diff --git a/src/compiler/binder.ts b/src/compiler/binder.ts
index 7ce19bc264fb8..d6bc1769ea5f3 100644
--- a/src/compiler/binder.ts
+++ b/src/compiler/binder.ts
@@ -84,6 +84,7 @@ import {
     getContainingClass,
     getEffectiveContainerForJSDocTemplateTag,
     getElementOrPropertyAccessName,
+    getEmitModuleResolutionKind,
     getEmitScriptTarget,
     getEnclosingBlockScopeContainer,
     getErrorSpanForNode,
@@ -235,6 +236,7 @@ import {
     ModifierFlags,
     ModuleBlock,
     ModuleDeclaration,
+    ModuleResolutionKind,
     Mutable,
     NamespaceExportDeclaration,
     Node,
@@ -3520,6 +3522,7 @@ function createBinder(): (file: SourceFile, options: CompilerOptions) => void {
         if (!isBindingPattern(node.name)) {
             const possibleVariableDecl = node.kind === SyntaxKind.VariableDeclaration ? node : node.parent.parent;
             if (isInJSFile(node) &&
+                getEmitModuleResolutionKind(options) !== ModuleResolutionKind.Bundler &&
                 isVariableDeclarationInitializedToBareOrAccessedRequire(possibleVariableDecl) &&
                 !getJSDocTypeTag(node) &&
                 !(getCombinedModifierFlags(node) & ModifierFlags.Export)
diff --git a/src/compiler/checker.ts b/src/compiler/checker.ts
index 963981dde4743..3d9d48b1bb893 100644
--- a/src/compiler/checker.ts
+++ b/src/compiler/checker.ts
@@ -139,6 +139,7 @@ import {
     ElementFlags,
     EmitFlags,
     EmitHint,
+    emitModuleKindIsNonNodeESM,
     EmitResolver,
     EmitTextWriter,
     emptyArray,
@@ -317,6 +318,7 @@ import {
     getResolutionModeOverrideForClause,
     getResolvedExternalModuleName,
     getResolvedModule,
+    getResolveJsonModule,
     getRestParameterElementType,
     getRootDeclaration,
     getScriptTargetFeatures,
@@ -346,8 +348,8 @@ import {
     hasAccessorModifier,
     hasAmbientModifier,
     hasContextSensitiveParameters,
-    HasDecorators,
     hasDecorators,
+    HasDecorators,
     hasDynamicName,
     hasEffectiveModifier,
     hasEffectiveModifiers,
@@ -356,8 +358,8 @@ import {
     hasExtension,
     HasIllegalDecorators,
     HasIllegalModifiers,
-    HasInitializer,
     hasInitializer,
+    HasInitializer,
     hasJSDocNodes,
     hasJSDocParameterTags,
     hasJsonModuleEmitEnabled,
@@ -458,6 +460,7 @@ import {
     isConstructorTypeNode,
     isConstTypeReference,
     isDeclaration,
+    isDeclarationFileName,
     isDeclarationName,
     isDeclarationReadonly,
     isDecorator,
@@ -897,6 +900,7 @@ import {
     setTextRangePosEnd,
     setValueDeclaration,
     ShorthandPropertyAssignment,
+    shouldAllowImportingTsExtension,
     shouldPreserveConstEnums,
     Signature,
     SignatureDeclaration,
@@ -4543,6 +4547,7 @@ export function createTypeChecker(host: TypeCheckerHost): TypeChecker {
             if (
                 namespace.valueDeclaration &&
                 isInJSFile(namespace.valueDeclaration) &&
+                getEmitModuleResolutionKind(compilerOptions) !== ModuleResolutionKind.Bundler &&
                 isVariableDeclaration(namespace.valueDeclaration) &&
                 namespace.valueDeclaration.initializer &&
                 isCommonJsRequire(namespace.valueDeclaration.initializer)
@@ -4727,6 +4732,7 @@ export function createTypeChecker(host: TypeCheckerHost): TypeChecker {
                 (isModuleDeclaration(location) ? location : location.parent && isModuleDeclaration(location.parent) && location.parent.name === location ? location.parent : undefined)?.name ||
                 (isLiteralImportTypeNode(location) ? location : undefined)?.argument.literal;
         const mode = contextSpecifier && isStringLiteralLike(contextSpecifier) ? getModeForUsageLocation(currentSourceFile, contextSpecifier) : currentSourceFile.impliedNodeFormat;
+        const moduleResolutionKind = getEmitModuleResolutionKind(compilerOptions);
         const resolvedModule = getResolvedModule(currentSourceFile, moduleReference, mode);
         const resolutionDiagnostic = resolvedModule && getResolutionDiagnostic(compilerOptions, resolvedModule);
         const sourceFile = resolvedModule
@@ -4737,11 +4743,28 @@ export function createTypeChecker(host: TypeCheckerHost): TypeChecker {
             if (resolutionDiagnostic) {
                 error(errorNode, resolutionDiagnostic, moduleReference, resolvedModule.resolvedFileName);
             }
+
+            if (resolvedModule.resolvedUsingTsExtension && isDeclarationFileName(moduleReference)) {
+                const importOrExport =
+                    findAncestor(location, isImportDeclaration)?.importClause ||
+                    findAncestor(location, or(isImportEqualsDeclaration, isExportDeclaration));
+                if (importOrExport && !importOrExport.isTypeOnly || findAncestor(location, isImportCall)) {
+                    error(
+                        errorNode,
+                        Diagnostics.A_declaration_file_cannot_be_imported_without_import_type_Did_you_mean_to_import_an_implementation_file_0_instead,
+                        getSuggestedImportSource(Debug.checkDefined(tryExtractTSExtension(moduleReference))));
+                }
+            }
+            else if (resolvedModule.resolvedUsingTsExtension && !shouldAllowImportingTsExtension(compilerOptions, currentSourceFile.fileName)) {
+                const tsExtension = Debug.checkDefined(tryExtractTSExtension(moduleReference));
+                error(errorNode, Diagnostics.An_import_path_can_only_end_with_a_0_extension_when_allowImportingTsExtensions_is_enabled, tsExtension);
+            }
+
             if (sourceFile.symbol) {
                 if (resolvedModule.isExternalLibraryImport && !resolutionExtensionIsTSOrJson(resolvedModule.extension)) {
                     errorOnImplicitAnyModule(/*isError*/ false, errorNode, resolvedModule, moduleReference);
                 }
-                if (getEmitModuleResolutionKind(compilerOptions) === ModuleResolutionKind.Node16 || getEmitModuleResolutionKind(compilerOptions) === ModuleResolutionKind.NodeNext) {
+                if (moduleResolutionKind === ModuleResolutionKind.Node16 || moduleResolutionKind === ModuleResolutionKind.NodeNext) {
                     const isSyncImport = (currentSourceFile.impliedNodeFormat === ModuleKind.CommonJS && !findAncestor(location, isImportCall)) || !!findAncestor(location, isImportEqualsDeclaration);
                     const overrideClauseHost = findAncestor(location, l => isImportTypeNode(l) || isExportDeclaration(l) || isImportDeclaration(l)) as ImportTypeNode | ImportDeclaration | ExportDeclaration | undefined;
                     const overrideClause = overrideClauseHost && isImportTypeNode(overrideClauseHost) ? overrideClauseHost.assertions?.assertClause : overrideClauseHost?.assertClause;
@@ -4849,25 +4872,14 @@ export function createTypeChecker(host: TypeCheckerHost): TypeChecker {
             else {
                 const tsExtension = tryExtractTSExtension(moduleReference);
                 const isExtensionlessRelativePathImport = pathIsRelative(moduleReference) && !hasExtension(moduleReference);
-                const moduleResolutionKind = getEmitModuleResolutionKind(compilerOptions);
                 const resolutionIsNode16OrNext = moduleResolutionKind === ModuleResolutionKind.Node16 ||
                     moduleResolutionKind === ModuleResolutionKind.NodeNext;
                 if (tsExtension) {
-                    const diag = Diagnostics.An_import_path_cannot_end_with_a_0_extension_Consider_importing_1_instead;
-                    const importSourceWithoutExtension = removeExtension(moduleReference, tsExtension);
-                    let replacedImportSource = importSourceWithoutExtension;
-                    /**
-                     * Direct users to import source with .js extension if outputting an ES module.
-                     * @see https://github.com/microsoft/TypeScript/issues/42151
-                     */
-                    if (moduleKind >= ModuleKind.ES2015) {
-                        replacedImportSource += tsExtension === Extension.Mts ? ".mjs" : tsExtension === Extension.Cts ? ".cjs" : ".js";
-                    }
-                    error(errorNode, diag, tsExtension, replacedImportSource);
-                }
-                else if (!compilerOptions.resolveJsonModule &&
+                    errorOnTSExtensionImport(tsExtension);
+                }
+                else if (!getResolveJsonModule(compilerOptions) &&
                     fileExtensionIs(moduleReference, Extension.Json) &&
-                    getEmitModuleResolutionKind(compilerOptions) !== ModuleResolutionKind.Classic &&
+                    moduleResolutionKind !== ModuleResolutionKind.Classic &&
                     hasJsonModuleEmitEnabled(compilerOptions)) {
                     error(errorNode, Diagnostics.Cannot_find_module_0_Consider_using_resolveJsonModule_to_import_module_with_json_extension, moduleReference);
                 }
@@ -4889,6 +4901,23 @@ export function createTypeChecker(host: TypeCheckerHost): TypeChecker {
             }
         }
         return undefined;
+
+        function errorOnTSExtensionImport(tsExtension: string) {
+            const diag = Diagnostics.An_import_path_cannot_end_with_a_0_extension_Consider_importing_1_instead;
+            error(errorNode, diag, tsExtension, getSuggestedImportSource(tsExtension));
+        }
+
+        function getSuggestedImportSource(tsExtension: string) {
+            const importSourceWithoutExtension = removeExtension(moduleReference, tsExtension);
+            /**
+             * Direct users to import source with .js extension if outputting an ES module.
+             * @see https://github.com/microsoft/TypeScript/issues/42151
+             */
+            if (emitModuleKindIsNonNodeESM(moduleKind) || mode === ModuleKind.ESNext) {
+                return importSourceWithoutExtension + (tsExtension === Extension.Mts ? ".mjs" : tsExtension === Extension.Cts ? ".cjs" : ".js");
+            }
+            return importSourceWithoutExtension;
+        }
     }
 
     function errorOnImplicitAnyModule(isError: boolean, errorNode: Node, { packageId, resolvedFileName }: ResolvedModuleFull, moduleReference: string): void {
@@ -33297,7 +33326,7 @@ export function createTypeChecker(host: TypeCheckerHost): TypeChecker {
         }
 
         // In JavaScript files, calls to any identifier 'require' are treated as external module imports
-        if (isInJSFile(node) && isCommonJsRequire(node)) {
+        if (isInJSFile(node) && getEmitModuleResolutionKind(compilerOptions) !== ModuleResolutionKind.Bundler && isCommonJsRequire(node)) {
             return resolveExternalModuleTypeByLiteral(node.arguments![0] as StringLiteral);
         }
 
@@ -42699,6 +42728,9 @@ export function createTypeChecker(host: TypeCheckerHost): TypeChecker {
                     // Import equals declaration is deprecated in es6 or above
                     grammarErrorOnNode(node, Diagnostics.Import_assignment_cannot_be_used_when_targeting_ECMAScript_modules_Consider_using_import_Asterisk_as_ns_from_mod_import_a_from_mod_import_d_from_mod_or_another_module_format_instead);
                 }
+                else if (getEmitModuleResolutionKind(compilerOptions) === ModuleResolutionKind.Bundler) {
+                    grammarErrorOnNode(node, Diagnostics.Import_assignment_is_not_allowed_when_moduleResolution_is_set_to_bundler_Consider_using_import_Asterisk_as_ns_from_mod_import_a_from_mod_import_d_from_mod_or_another_module_format_instead);
+                }
             }
         }
     }
@@ -42921,6 +42953,9 @@ export function createTypeChecker(host: TypeCheckerHost): TypeChecker {
                 // system modules does not support export assignment
                 grammarErrorOnNode(node, Diagnostics.Export_assignment_is_not_supported_when_module_flag_is_system);
             }
+            else if (getEmitModuleResolutionKind(compilerOptions) === ModuleResolutionKind.Bundler) {
+                grammarErrorOnNode(node, Diagnostics.Export_assignment_cannot_be_used_when_moduleResolution_is_set_to_bundler_Consider_using_export_default_or_another_module_format_instead);
+            }
         }
     }
 
@@ -44015,7 +44050,7 @@ export function createTypeChecker(host: TypeCheckerHost): TypeChecker {
                 // 4). type A = import("./f/*gotToDefinitionHere*/oo")
                 if ((isExternalModuleImportEqualsDeclaration(node.parent.parent) && getExternalModuleImportEqualsDeclarationExpression(node.parent.parent) === node) ||
                     ((node.parent.kind === SyntaxKind.ImportDeclaration || node.parent.kind === SyntaxKind.ExportDeclaration) && (node.parent as ImportDeclaration).moduleSpecifier === node) ||
-                    ((isInJSFile(node) && isRequireCall(node.parent, /*checkArgumentIsStringLiteralLike*/ false)) || isImportCall(node.parent)) ||
+                    ((isInJSFile(node) && getEmitModuleResolutionKind(compilerOptions) !== ModuleResolutionKind.Bundler && isRequireCall(node.parent, /*checkArgumentIsStringLiteralLike*/ false)) || isImportCall(node.parent)) ||
                     (isLiteralTypeNode(node.parent) && isLiteralImportTypeNode(node.parent.parent) && node.parent.parent.argument === node.parent)
                 ) {
                     return resolveExternalModuleName(node, node as LiteralExpression, ignoreErrors);
@@ -47321,4 +47356,4 @@ class SymbolTrackerImpl implements SymbolTracker {
     private onDiagnosticReported() {
         this.context.reportedDiagnostic = true;
     }
-}
\ No newline at end of file
+}
diff --git a/src/compiler/commandLineParser.ts b/src/compiler/commandLineParser.ts
index 97a09f716345e..e8f5452edfcba 100644
--- a/src/compiler/commandLineParser.ts
+++ b/src/compiler/commandLineParser.ts
@@ -965,6 +965,7 @@ const commandOptionsWithoutBuild: CommandLineOption[] = [
             classic: ModuleResolutionKind.Classic,
             node16: ModuleResolutionKind.Node16,
             nodenext: ModuleResolutionKind.NodeNext,
+            bundler: ModuleResolutionKind.Bundler,
         })),
         affectsModuleResolution: true,
         paramType: Diagnostics.STRATEGY,
@@ -1081,6 +1082,41 @@ const commandOptionsWithoutBuild: CommandLineOption[] = [
         category: Diagnostics.Modules,
         description: Diagnostics.List_of_file_name_suffixes_to_search_when_resolving_a_module,
     },
+    {
+        name: "allowImportingTsExtensions",
+        type: "boolean",
+        affectsModuleResolution: true,
+        category: Diagnostics.Modules,
+        description: Diagnostics.Allow_imports_to_include_TypeScript_file_extensions_Requires_moduleResolution_bundler_and_either_noEmit_or_emitDeclarationOnly_to_be_set,
+        defaultValueDescription: false,
+    },
+    {
+        name: "resolvePackageJsonExports",
+        type: "boolean",
+        affectsModuleResolution: true,
+        category: Diagnostics.Modules,
+        description: Diagnostics.Use_the_package_json_exports_field_when_resolving_package_imports,
+        defaultValueDescription: Diagnostics.true_when_moduleResolution_is_node16_nodenext_or_bundler_otherwise_false,
+    },
+    {
+        name: "resolvePackageJsonImports",
+        type: "boolean",
+        affectsModuleResolution: true,
+        category: Diagnostics.Modules,
+        description: Diagnostics.Use_the_package_json_imports_field_when_resolving_imports,
+        defaultValueDescription: Diagnostics.true_when_moduleResolution_is_node16_nodenext_or_bundler_otherwise_false,
+    },
+    {
+        name: "customConditions",
+        type: "list",
+        element: {
+            name: "condition",
+            type: "string",
+        },
+        affectsModuleResolution: true,
+        category: Diagnostics.Modules,
+        description: Diagnostics.Conditions_to_set_in_addition_to_the_resolver_specific_defaults_when_resolving_imports,
+    },
 
     // Source Maps
     {
diff --git a/src/compiler/diagnosticMessages.json b/src/compiler/diagnosticMessages.json
index e146cce88c8cb..ad3d9ec3e3eba 100644
--- a/src/compiler/diagnosticMessages.json
+++ b/src/compiler/diagnosticMessages.json
@@ -3563,6 +3563,10 @@
         "category": "Error",
         "code": 2845
     },
+    "A declaration file cannot be imported without 'import type'. Did you mean to import an implementation file '{0}' instead?": {
+        "category": "Error",
+        "code": 2846
+    },
 
     "Import declaration '{0}' is using private name '{1}'.": {
         "category": "Error",
@@ -4221,6 +4225,26 @@
         "category": "Error",
         "code": 5095
     },
+    "Option 'allowImportingTsExtensions' can only be used when 'moduleResolution' is set to 'bundler' and either 'noEmit' or 'emitDeclarationOnly' is set.": {
+        "category": "Error",
+        "code": 5096
+    },
+    "An import path can only end with a '{0}' extension when 'allowImportingTsExtensions' is enabled.": {
+        "category": "Error",
+        "code": 5097
+    },
+    "Option '{0}' can only be used when 'moduleResolution' is set to 'node16', 'nodenext', or 'bundler'.": {
+        "category": "Error",
+        "code": 5098
+    },
+    "Import assignment is not allowed when 'moduleResolution' is set to 'bundler'. Consider using 'import * as ns from \"mod\"', 'import {a} from \"mod\"', 'import d from \"mod\"', or another module format instead.": {
+        "category": "Error",
+        "code": 5099
+    },
+    "Export assignment cannot be used when 'moduleResolution' is set to 'bundler'. Consider using 'export default' or another module format instead.": {
+        "category": "Error",
+        "code": 5100
+    },
 
     "Generates a sourcemap for each corresponding '.d.ts' file.": {
         "category": "Message",
@@ -4443,10 +4467,6 @@
         "category": "Message",
         "code": 6066
     },
-    "Specify module resolution strategy: 'node' (Node.js) or 'classic' (TypeScript pre-1.6).": {
-        "category": "Message",
-        "code": 6069
-    },
     "Initializes a TypeScript project and creates a tsconfig.json file.": {
         "category": "Message",
         "code": 6070
@@ -5430,6 +5450,26 @@
         "category": "Message",
         "code": 6406
     },
+    "Allow imports to include TypeScript file extensions. Requires '--moduleResolution bundler' and either '--noEmit' or '--emitDeclarationOnly' to be set.": {
+        "category": "Message",
+        "code": 6407
+    },
+    "Use the package.json 'exports' field when resolving package imports.": {
+        "category": "Message",
+        "code": 6408
+    },
+    "Use the package.json 'imports' field when resolving imports.": {
+        "category": "Message",
+        "code": 6409
+    },
+    "Conditions to set in addition to the resolver-specific defaults when resolving imports.": {
+        "category": "Message",
+        "code": 6410
+    },
+    "`true` when 'moduleResolution' is 'node16', 'nodenext', or 'bundler'; otherwise `false`.": {
+        "category": "Message",
+        "code": 6411
+    },
 
     "The expected type comes from property '{0}' which is declared here on type '{1}'": {
         "category": "Message",
diff --git a/src/compiler/moduleNameResolver.ts b/src/compiler/moduleNameResolver.ts
index fd9cf539fc333..5a1c504bc2515 100644
--- a/src/compiler/moduleNameResolver.ts
+++ b/src/compiler/moduleNameResolver.ts
@@ -2,6 +2,7 @@ import {
     append,
     appendIfUnique,
     arrayFrom,
+    arrayIsEqualTo,
     changeAnyExtension,
     CharacterCodes,
     combinePaths,
@@ -9,10 +10,12 @@ import {
     comparePaths,
     Comparison,
     CompilerOptions,
+    concatenate,
     contains,
     containsPath,
     createCompilerDiagnostic,
     Debug,
+    deduplicate,
     Diagnostic,
     DiagnosticMessage,
     DiagnosticReporter,
@@ -47,12 +50,14 @@ import {
     getPathsBasePath,
     getPossibleOriginalInputExtensionForExtension,
     getRelativePathFromDirectory,
+    getResolveJsonModule,
     getRootLength,
     hasJSFileExtension,
     hasProperty,
     hasTrailingDirectorySeparator,
     hostGetCanonicalFileName,
     isArray,
+    isDeclarationFileName,
     isExternalModuleNameRelative,
     isRootedDiskPath,
     isString,
@@ -94,6 +99,7 @@ import {
     startsWith,
     stringContains,
     supportedDeclarationExtensions,
+    supportedTSExtensionsFlat,
     supportedTSImplementationExtensions,
     toPath,
     tryExtractTSExtension,
@@ -128,7 +134,7 @@ function withPackageId(packageInfo: PackageJsonInfo | undefined, r: PathAndExten
             };
         }
     }
-    return r && { path: r.path, extension: r.ext, packageId };
+    return r && { path: r.path, extension: r.ext, packageId, resolvedUsingTsExtension: r.resolvedUsingTsExtension };
 }
 
 function noPackageId(r: PathAndExtension | undefined): Resolved | undefined {
@@ -138,7 +144,7 @@ function noPackageId(r: PathAndExtension | undefined): Resolved | undefined {
 function removeIgnoredPackageId(r: Resolved | undefined): PathAndExtension | undefined {
     if (r) {
         Debug.assert(r.packageId === undefined);
-        return { path: r.path, ext: r.extension };
+        return { path: r.path, ext: r.extension, resolvedUsingTsExtension: r.resolvedUsingTsExtension };
     }
 }
 
@@ -157,6 +163,7 @@ interface Resolved {
      * Note: This is a file name with preserved original casing, not a normalized `Path`.
      */
     originalPath?: string | true;
+    resolvedUsingTsExtension: boolean | undefined;
 }
 
 /** Result of trying to resolve a module at a file. Needs to have 'packageId' added later. */
@@ -164,6 +171,7 @@ interface PathAndExtension {
     path: string;
     // (Use a different name than `extension` to make sure Resolved isn't assignable to PathAndExtension.)
     ext: Extension;
+    resolvedUsingTsExtension: boolean | undefined;
 }
 
 /**
@@ -215,7 +223,14 @@ function createResolvedModuleWithFailedLookupLocations(
         return resultFromCache;
     }
     return {
-        resolvedModule: resolved && { resolvedFileName: resolved.path, originalPath: resolved.originalPath === true ? undefined : resolved.originalPath, extension: resolved.extension, isExternalLibraryImport, packageId: resolved.packageId },
+        resolvedModule: resolved && {
+            resolvedFileName: resolved.path,
+            originalPath: resolved.originalPath === true ? undefined : resolved.originalPath,
+            extension: resolved.extension,
+            isExternalLibraryImport,
+            packageId: resolved.packageId,
+            resolvedUsingTsExtension: !!resolved.resolvedUsingTsExtension,
+        },
         failedLookupLocations: initializeResolutionField(failedLookupLocations),
         affectingLocations: initializeResolutionField(affectingLocations),
         resolutionDiagnostics: initializeResolutionField(diagnostics),
@@ -488,7 +503,7 @@ export function resolveTypeReferenceDirective(typeReferenceDirectiveName: string
 
     const failedLookupLocations: string[] = [];
     const affectingLocations: string[] = [];
-    let features = getDefaultNodeResolutionFeatures(options);
+    let features = getNodeResolutionFeatures(options);
     // Unlike `import` statements, whose mode-calculating APIs are all guaranteed to return `undefined` if we're in an un-mode-ed module resolution
     // setting, type references will return their target mode regardless of options because of how the parser works, so we guard against the mode being
     // set in a non-modal module resolution setting here. Do note that our behavior is not particularly well defined when these mode-overriding imports
@@ -499,7 +514,7 @@ export function resolveTypeReferenceDirective(typeReferenceDirectiveName: string
     if (resolutionMode === ModuleKind.ESNext && (getEmitModuleResolutionKind(options) === ModuleResolutionKind.Node16 || getEmitModuleResolutionKind(options) === ModuleResolutionKind.NodeNext)) {
         features |= NodeResolutionFeatures.EsmMode;
     }
-    const conditions = features & NodeResolutionFeatures.Exports ? features & NodeResolutionFeatures.EsmMode ? ["node", "import", "types"] : ["node", "require", "types"] : [];
+    const conditions = features & NodeResolutionFeatures.Exports ? getConditions(options, !!(features & NodeResolutionFeatures.EsmMode)) : [];
     const diagnostics: Diagnostic[] = [];
     const moduleResolutionState: ModuleResolutionState = {
         compilerOptions: options,
@@ -614,10 +629,44 @@ export function resolveTypeReferenceDirective(typeReferenceDirectiveName: string
     }
 }
 
-function getDefaultNodeResolutionFeatures(options: CompilerOptions) {
-    return getEmitModuleResolutionKind(options) === ModuleResolutionKind.Node16 ? NodeResolutionFeatures.Node16Default :
-        getEmitModuleResolutionKind(options) === ModuleResolutionKind.NodeNext ? NodeResolutionFeatures.NodeNextDefault :
-            NodeResolutionFeatures.None;
+function getNodeResolutionFeatures(options: CompilerOptions) {
+    let features = NodeResolutionFeatures.None;
+    switch (getEmitModuleResolutionKind(options)) {
+        case ModuleResolutionKind.Node16:
+            features = NodeResolutionFeatures.Node16Default;
+            break;
+        case ModuleResolutionKind.NodeNext:
+            features = NodeResolutionFeatures.NodeNextDefault;
+            break;
+        case ModuleResolutionKind.Bundler:
+            features = NodeResolutionFeatures.BundlerDefault;
+            break;
+    }
+    if (options.resolvePackageJsonExports) {
+        features |= NodeResolutionFeatures.Exports;
+    }
+    else if (options.resolvePackageJsonExports === false) {
+        features &= ~NodeResolutionFeatures.Exports;
+    }
+    if (options.resolvePackageJsonImports) {
+        features |= NodeResolutionFeatures.Imports;
+    }
+    else if (options.resolvePackageJsonImports === false) {
+        features &= ~NodeResolutionFeatures.Imports;
+    }
+    return features;
+}
+
+function getConditions(options: CompilerOptions, esmMode?: boolean) {
+    // conditions are only used by the node16/nodenext/bundler resolvers - there's no priority order in the list,
+    // it's essentially a set (priority is determined by object insertion order in the object we look at).
+    const conditions = esmMode || getEmitModuleResolutionKind(options) === ModuleResolutionKind.Bundler
+        ? ["node", "import"]
+        : ["node", "require"];
+    if (!options.noDtsResolution) {
+        conditions.push("types");
+    }
+    return concatenate(conditions, options.customConditions);
 }
 
 /**
@@ -1235,6 +1284,9 @@ export function resolveModuleName(moduleName: string, containingFile: string, co
             case ModuleResolutionKind.Classic:
                 result = classicNameResolver(moduleName, containingFile, compilerOptions, host, cache, redirectedReference);
                 break;
+            case ModuleResolutionKind.Bundler:
+                result = bundlerModuleNameResolver(moduleName, containingFile, compilerOptions, host, cache, redirectedReference);
+                break;
             default:
                 return Debug.fail(`Unexpected moduleResolution: ${moduleResolution}`);
         }
@@ -1489,6 +1541,8 @@ export enum NodeResolutionFeatures {
 
     NodeNextDefault = AllFeatures,
 
+    BundlerDefault = Imports | SelfName | Exports | ExportsPatternTrailers,
+
     EsmMode = 1 << 5,
 }
 
@@ -1528,7 +1582,7 @@ function nodeNextModuleNameResolverWorker(features: NodeResolutionFeatures, modu
     // es module file or cjs-like input file, use a variant of the legacy cjs resolver that supports the selected modern features
     const esmMode = resolutionMode === ModuleKind.ESNext ? NodeResolutionFeatures.EsmMode : 0;
     let extensions = compilerOptions.noDtsResolution ? Extensions.ImplementationFiles : Extensions.TypeScript | Extensions.JavaScript | Extensions.Declaration;
-    if (compilerOptions.resolveJsonModule) {
+    if (getResolveJsonModule(compilerOptions)) {
         extensions |= Extensions.Json;
     }
     return nodeModuleNameResolverWorker(features | esmMode, moduleName, containingDirectory, compilerOptions, host, cache, extensions, /*isConfigLookup*/ false, redirectedReference);
@@ -1547,6 +1601,15 @@ function tryResolveJSModuleWorker(moduleName: string, initialDir: string, host:
         /*redirectedReferences*/ undefined);
 }
 
+export function bundlerModuleNameResolver(moduleName: string, containingFile: string, compilerOptions: CompilerOptions, host: ModuleResolutionHost, cache?: ModuleResolutionCache, redirectedReference?: ResolvedProjectReference): ResolvedModuleWithFailedLookupLocations {
+    const containingDirectory = getDirectoryPath(containingFile);
+    let extensions = compilerOptions.noDtsResolution ? Extensions.ImplementationFiles : Extensions.TypeScript | Extensions.JavaScript | Extensions.Declaration;
+    if (getResolveJsonModule(compilerOptions)) {
+        extensions |= Extensions.Json;
+    }
+    return nodeModuleNameResolverWorker(getNodeResolutionFeatures(compilerOptions), moduleName, containingDirectory, compilerOptions, host, cache, extensions, /*isConfigLookup*/ false, redirectedReference);
+}
+
 export function nodeModuleNameResolver(moduleName: string, containingFile: string, compilerOptions: CompilerOptions, host: ModuleResolutionHost, cache?: ModuleResolutionCache, redirectedReference?: ResolvedProjectReference): ResolvedModuleWithFailedLookupLocations;
 /** @internal */ export function nodeModuleNameResolver(moduleName: string, containingFile: string, compilerOptions: CompilerOptions, host: ModuleResolutionHost, cache?: ModuleResolutionCache, redirectedReference?: ResolvedProjectReference, lookupConfig?: boolean): ResolvedModuleWithFailedLookupLocations; // eslint-disable-line @typescript-eslint/unified-signatures
 export function nodeModuleNameResolver(moduleName: string, containingFile: string, compilerOptions: CompilerOptions, host: ModuleResolutionHost, cache?: ModuleResolutionCache, redirectedReference?: ResolvedProjectReference, isConfigLookup?: boolean): ResolvedModuleWithFailedLookupLocations {
@@ -1556,10 +1619,10 @@ export function nodeModuleNameResolver(moduleName: string, containingFile: strin
     }
     else if (compilerOptions.noDtsResolution) {
         extensions = Extensions.ImplementationFiles;
-        if (compilerOptions.resolveJsonModule) extensions |= Extensions.Json;
+        if (getResolveJsonModule(compilerOptions)) extensions |= Extensions.Json;
     }
     else {
-        extensions = compilerOptions.resolveJsonModule
+        extensions = getResolveJsonModule(compilerOptions)
             ? Extensions.TypeScript | Extensions.JavaScript | Extensions.Declaration | Extensions.Json
             : Extensions.TypeScript | Extensions.JavaScript | Extensions.Declaration;
     }
@@ -1571,12 +1634,7 @@ function nodeModuleNameResolverWorker(features: NodeResolutionFeatures, moduleNa
 
     const failedLookupLocations: string[] = [];
     const affectingLocations: string[] = [];
-    // conditions are only used by the node16/nodenext resolver - there's no priority order in the list,
-    //it's essentially a set (priority is determined by object insertion order in the object we look at).
-    const conditions = features & NodeResolutionFeatures.EsmMode ? ["node", "import", "types"] : ["node", "require", "types"];
-    if (compilerOptions.noDtsResolution) {
-        conditions.pop();
-    }
+    const conditions = getConditions(compilerOptions, !!(features & NodeResolutionFeatures.EsmMode));
 
     const diagnostics: Diagnostic[] = [];
     const state: ModuleResolutionState = {
@@ -1720,7 +1778,7 @@ function nodeLoadModuleByRelativeName(extensions: Extensions, candidate: string,
         }
     }
     // esm mode relative imports shouldn't do any directory lookups (either inside `package.json`
-    // files or implicit `index.js`es). This is a notable depature from cjs norms, where `./foo/pkg`
+    // files or implicit `index.js`es). This is a notable departure from cjs norms, where `./foo/pkg`
     // could have been redirected by `./foo/pkg/package.json` to an arbitrary location!
     if (!(state.features & NodeResolutionFeatures.EsmMode)) {
         return loadNodeModuleFromDirectory(extensions, candidate, onlyRecordFailures, state, considerPackageJson);
@@ -1795,7 +1853,12 @@ function loadModuleFromFile(extensions: Extensions, candidate: string, onlyRecor
 function loadModuleFromFileNoImplicitExtensions(extensions: Extensions, candidate: string, onlyRecordFailures: boolean, state: ModuleResolutionState): PathAndExtension | undefined {
     // If that didn't work, try stripping a ".js" or ".jsx" extension and replacing it with a TypeScript one;
     // e.g. "./foo.js" can be matched by "./foo.ts" or "./foo.d.ts"
-    if (hasJSFileExtension(candidate) || extensions & Extensions.Json && fileExtensionIs(candidate, Extension.Json)) {
+    if (hasJSFileExtension(candidate) ||
+        extensions & Extensions.Json && fileExtensionIs(candidate, Extension.Json) ||
+        extensions & (Extensions.TypeScript | Extensions.Declaration)
+            && moduleResolutionSupportsResolvingTsExtensions(state.compilerOptions)
+            && fileExtensionIsOneOf(candidate, supportedTSExtensionsFlat)
+    ) {
         const extensionless = removeFileExtension(candidate);
         const extension = candidate.substring(extensionless.length);
         if (state.traceEnabled) {
@@ -1810,7 +1873,7 @@ function loadJSOrExactTSFileName(extensions: Extensions, candidate: string, only
         extensions & Extensions.Declaration && fileExtensionIsOneOf(candidate, supportedDeclarationExtensions)
     ) {
         const result = tryFile(candidate, onlyRecordFailures, state);
-        return result !== undefined ? { path: candidate, ext: tryExtractTSExtension(candidate) as Extension } : undefined;
+        return result !== undefined ? { path: candidate, ext: tryExtractTSExtension(candidate) as Extension, resolvedUsingTsExtension: undefined } : undefined;
     }
 
     return loadModuleFromFileNoImplicitExtensions(extensions, candidate, onlyRecordFailures, state);
@@ -1854,6 +1917,13 @@ function tryAddingExtensions(candidate: string, extensions: Extensions, original
                 if (result) return result;
             }
             return undefined;
+        case Extension.Ts:
+        case Extension.Tsx:
+        case Extension.Dts:
+            if (moduleResolutionSupportsResolvingTsExtensions(state.compilerOptions) && extensionIsOk(extensions, originalExtension)) {
+                return tryExtension(originalExtension, /*resolvedUsingTsExtension*/ true);
+            }
+            // falls through
         default:
             return extensions & Extensions.TypeScript && (tryExtension(Extension.Ts) || tryExtension(Extension.Tsx))
                 || extensions & Extensions.Declaration && tryExtension(Extension.Dts)
@@ -1863,9 +1933,9 @@ function tryAddingExtensions(candidate: string, extensions: Extensions, original
 
     }
 
-    function tryExtension(ext: Extension): PathAndExtension | undefined {
+    function tryExtension(ext: Extension, resolvedUsingTsExtension?: boolean): PathAndExtension | undefined {
         const path = tryFile(candidate + ext, onlyRecordFailures, state);
-        return path === undefined ? undefined : { path, ext };
+        return path === undefined ? undefined : { path, ext, resolvedUsingTsExtension };
     }
 }
 
@@ -1921,26 +1991,30 @@ export function getEntrypointsFromPackageJsonInfo(
 
     let entrypoints: string[] | undefined;
     const extensions = Extensions.TypeScript | Extensions.Declaration | (resolveJs ? Extensions.JavaScript : 0);
-    const features = getDefaultNodeResolutionFeatures(options);
-    const requireState = getTemporaryModuleResolutionState(cache?.getPackageJsonInfoCache(), host, options);
-    requireState.conditions = ["node", "require", "types"];
-    requireState.requestContainingDirectory = packageJsonInfo.packageDirectory;
-    const requireResolution = loadNodeModuleFromDirectoryWorker(
+    const features = getNodeResolutionFeatures(options);
+    const loadPackageJsonMainState = getTemporaryModuleResolutionState(cache?.getPackageJsonInfoCache(), host, options);
+    loadPackageJsonMainState.conditions = getConditions(options);
+    loadPackageJsonMainState.requestContainingDirectory = packageJsonInfo.packageDirectory;
+    const mainResolution = loadNodeModuleFromDirectoryWorker(
         extensions,
         packageJsonInfo.packageDirectory,
         /*onlyRecordFailures*/ false,
-        requireState,
+        loadPackageJsonMainState,
         packageJsonInfo.contents.packageJsonContent,
-        getVersionPathsOfPackageJsonInfo(packageJsonInfo, requireState));
-    entrypoints = append(entrypoints, requireResolution?.path);
+        getVersionPathsOfPackageJsonInfo(packageJsonInfo, loadPackageJsonMainState));
+    entrypoints = append(entrypoints, mainResolution?.path);
 
     if (features & NodeResolutionFeatures.Exports && packageJsonInfo.contents.packageJsonContent.exports) {
-        for (const conditions of [["node", "import", "types"], ["node", "require", "types"]]) {
-            const exportState = { ...requireState, failedLookupLocations: [], conditions };
+        const conditionSets = deduplicate(
+            [getConditions(options, /*esmMode*/ true), getConditions(options, /*esmMode*/ false)],
+            arrayIsEqualTo
+        );
+        for (const conditions of conditionSets) {
+            const loadPackageJsonExportsState = { ...loadPackageJsonMainState, failedLookupLocations: [], conditions };
             const exportResolutions = loadEntrypointsFromExportMap(
                 packageJsonInfo,
                 packageJsonInfo.contents.packageJsonContent.exports,
-                exportState,
+                loadPackageJsonExportsState,
                 extensions);
             if (exportResolutions) {
                 for (const resolution of exportResolutions) {
@@ -2046,7 +2120,7 @@ export interface PackageJsonInfoContents {
  *
  * @internal
  */
- export function getPackageScopeForPath(fileName: string, state: ModuleResolutionState): PackageJsonInfo | undefined {
+export function getPackageScopeForPath(fileName: string, state: ModuleResolutionState): PackageJsonInfo | undefined {
     const parts = getPathComponents(fileName);
     parts.pop();
     while (parts.length > 0) {
@@ -2179,9 +2253,9 @@ function loadNodeModuleFromDirectoryWorker(extensions: Extensions, candidate: st
 }
 
 /** Resolve from an arbitrarily specified file. Return `undefined` if it has an unsupported extension. */
-function resolvedIfExtensionMatches(extensions: Extensions, path: string): PathAndExtension | undefined {
+function resolvedIfExtensionMatches(extensions: Extensions, path: string, resolvedUsingTsExtension?: boolean): PathAndExtension | undefined {
     const ext = tryGetExtensionFromPath(path);
-    return ext !== undefined && extensionIsOk(extensions, ext) ? { path, ext } : undefined;
+    return ext !== undefined && extensionIsOk(extensions, ext) ? { path, ext, resolvedUsingTsExtension } : undefined;
 }
 
 /** True if `extension` is one of the supported `extensions`. */
@@ -2372,7 +2446,13 @@ function getLoadModuleFromTargetImportOrExport(extensions: Extensions, state: Mo
                     traceIfEnabled(state, Diagnostics.Using_0_subpath_1_with_target_2, "imports", key, combinedLookup);
                     traceIfEnabled(state, Diagnostics.Resolving_module_0_from_1, combinedLookup, scope.packageDirectory + "/");
                     const result = nodeModuleNameResolverWorker(state.features, combinedLookup, scope.packageDirectory + "/", state.compilerOptions, state.host, cache, extensions, /*isConfigLookup*/ false, redirectedReference);
-                    return toSearchResult(result.resolvedModule ? { path: result.resolvedModule.resolvedFileName, extension: result.resolvedModule.extension, packageId: result.resolvedModule.packageId, originalPath: result.resolvedModule.originalPath } : undefined);
+                    return toSearchResult(result.resolvedModule ? {
+                        path: result.resolvedModule.resolvedFileName,
+                        extension: result.resolvedModule.extension,
+                        packageId: result.resolvedModule.packageId,
+                        originalPath: result.resolvedModule.originalPath,
+                        resolvedUsingTsExtension: result.resolvedModule.resolvedUsingTsExtension
+                    } : undefined);
                 }
                 if (state.traceEnabled) {
                     trace(state.host, Diagnostics.package_json_scope_0_has_invalid_type_for_target_of_specifier_1, scope.packageDirectory, moduleName);
@@ -2753,7 +2833,7 @@ function tryLoadModuleUsingPaths(extensions: Extensions, moduleName: string, bas
             if (extension !== undefined) {
                 const path = tryFile(candidate, onlyRecordFailures, state);
                 if (path !== undefined) {
-                    return noPackageId({ path, ext: extension });
+                    return noPackageId({ path, ext: extension, resolvedUsingTsExtension: undefined });
                 }
             }
             return loader(extensions, candidate, onlyRecordFailures || !directoryProbablyExists(getDirectoryPath(candidate), state.host), state);
@@ -2813,7 +2893,15 @@ function tryFindNonRelativeModuleNameInCache(cache: NonRelativeModuleNameResolut
             trace(state.host, Diagnostics.Resolution_for_module_0_was_found_in_cache_from_location_1, moduleName, containingDirectory);
         }
         state.resultFromCache = result;
-        return { value: result.resolvedModule && { path: result.resolvedModule.resolvedFileName, originalPath: result.resolvedModule.originalPath || true, extension: result.resolvedModule.extension, packageId: result.resolvedModule.packageId } };
+        return {
+            value: result.resolvedModule && {
+                path: result.resolvedModule.resolvedFileName,
+                originalPath: result.resolvedModule.originalPath || true,
+                extension: result.resolvedModule.extension,
+                packageId: result.resolvedModule.packageId,
+                resolvedUsingTsExtension: result.resolvedModule.resolvedUsingTsExtension
+            }
+        };
     }
 }
 
@@ -2880,6 +2968,18 @@ export function classicNameResolver(moduleName: string, containingFile: string,
     }
 }
 
+export function moduleResolutionSupportsResolvingTsExtensions(compilerOptions: CompilerOptions) {
+    return getEmitModuleResolutionKind(compilerOptions) === ModuleResolutionKind.Bundler;
+}
+
+// Program errors validate that `noEmit` or `emitDeclarationOnly` is also set,
+// so this function doesn't check them to avoid propagating errors.
+export function shouldAllowImportingTsExtension(compilerOptions: CompilerOptions, fromFileName?: string) {
+    return moduleResolutionSupportsResolvingTsExtensions(compilerOptions) && (
+        !!compilerOptions.allowImportingTsExtensions ||
+        fromFileName && isDeclarationFileName(fromFileName));
+}
+
 /**
  * A host may load a module from a global cache of typings.
  * This is the minumum code needed to expose that functionality; the rest is in the host.
diff --git a/src/compiler/moduleSpecifiers.ts b/src/compiler/moduleSpecifiers.ts
index c21a26c7dcb28..351d98a24bd19 100644
--- a/src/compiler/moduleSpecifiers.ts
+++ b/src/compiler/moduleSpecifiers.ts
@@ -34,9 +34,9 @@ import {
     GetCanonicalFileName,
     getDirectoryPath,
     getEmitModuleResolutionKind,
-    getImpliedNodeFormatForFile,
     getModeForResolutionAtIndex,
     getModuleNameStringLiteralAt,
+    getModuleSpecifierEndingPreference,
     getNodeModulePathParts,
     getNormalizedAbsolutePath,
     getOwnKeys,
@@ -54,6 +54,7 @@ import {
     Identifier,
     isAmbientModule,
     isApplicableVersionedTypesKey,
+    isDeclarationFileName,
     isExternalModuleAugmentation,
     isExternalModuleNameRelative,
     isModuleBlock,
@@ -71,9 +72,9 @@ import {
     ModuleDeclaration,
     ModuleKind,
     ModulePath,
-    ModuleResolutionHost,
     ModuleResolutionKind,
     ModuleSpecifierCache,
+    ModuleSpecifierEnding,
     ModuleSpecifierOptions,
     ModuleSpecifierResolutionHost,
     NodeFlags,
@@ -89,6 +90,7 @@ import {
     ResolutionMode,
     resolvePath,
     ScriptKind,
+    shouldAllowImportingTsExtension,
     some,
     SourceFile,
     startsWith,
@@ -107,61 +109,63 @@ import {
 // Used by importFixes, getEditsForFileRename, and declaration emit to synthesize import module specifiers.
 
 const enum RelativePreference { Relative, NonRelative, Shortest, ExternalNonRelative }
-// See UserPreferences#importPathEnding
-const enum Ending { Minimal, Index, JsExtension }
 
 // Processed preferences
 interface Preferences {
     readonly relativePreference: RelativePreference;
-    readonly ending: Ending;
+    /**
+     * @param syntaxImpliedNodeFormat Used when the import syntax implies ESM or CJS irrespective of the mode of the file.
+     */
+    getAllowedEndingsInPreferredOrder(syntaxImpliedNodeFormat?: SourceFile["impliedNodeFormat"]): ModuleSpecifierEnding[];
 }
 
-function getPreferences(host: ModuleSpecifierResolutionHost, { importModuleSpecifierPreference, importModuleSpecifierEnding }: UserPreferences, compilerOptions: CompilerOptions, importingSourceFile: SourceFile): Preferences {
+function getPreferences(
+    { importModuleSpecifierPreference, importModuleSpecifierEnding }: UserPreferences,
+    compilerOptions: CompilerOptions,
+    importingSourceFile: SourceFile,
+    oldImportSpecifier?: string,
+): Preferences {
+    const preferredEnding = getPreferredEnding();
     return {
         relativePreference:
+            oldImportSpecifier !== undefined ? (isExternalModuleNameRelative(oldImportSpecifier) ?
+                RelativePreference.Relative :
+                RelativePreference.NonRelative) :
             importModuleSpecifierPreference === "relative" ? RelativePreference.Relative :
             importModuleSpecifierPreference === "non-relative" ? RelativePreference.NonRelative :
             importModuleSpecifierPreference === "project-relative" ? RelativePreference.ExternalNonRelative :
             RelativePreference.Shortest,
-        ending: getEnding(),
-    };
-    function getEnding(): Ending {
-        switch (importModuleSpecifierEnding) {
-            case "minimal": return Ending.Minimal;
-            case "index": return Ending.Index;
-            case "js": return Ending.JsExtension;
-            default: return usesJsExtensionOnImports(importingSourceFile) || isFormatRequiringExtensions(compilerOptions, importingSourceFile.path, host) ? Ending.JsExtension
-                : getEmitModuleResolutionKind(compilerOptions) !== ModuleResolutionKind.NodeJs ? Ending.Index : Ending.Minimal;
-        }
-    }
-}
-
-function getPreferencesForUpdate(compilerOptions: CompilerOptions, oldImportSpecifier: string, importingSourceFileName: Path, host: ModuleSpecifierResolutionHost): Preferences {
-    return {
-        relativePreference: isExternalModuleNameRelative(oldImportSpecifier) ? RelativePreference.Relative : RelativePreference.NonRelative,
-        ending: hasJSFileExtension(oldImportSpecifier) || isFormatRequiringExtensions(compilerOptions, importingSourceFileName, host) ?
-            Ending.JsExtension :
-            getEmitModuleResolutionKind(compilerOptions) !== ModuleResolutionKind.NodeJs || endsWith(oldImportSpecifier, "index") ? Ending.Index : Ending.Minimal,
+        getAllowedEndingsInPreferredOrder: syntaxImpliedNodeFormat => {
+            if ((syntaxImpliedNodeFormat ?? importingSourceFile.impliedNodeFormat) === ModuleKind.ESNext) {
+                if (shouldAllowImportingTsExtension(compilerOptions, importingSourceFile.fileName)) {
+                    return [ModuleSpecifierEnding.TsExtension, ModuleSpecifierEnding.JsExtension];
+                }
+                return [ModuleSpecifierEnding.JsExtension];
+            }
+            if (getEmitModuleResolutionKind(compilerOptions) === ModuleResolutionKind.Classic) {
+                return [ModuleSpecifierEnding.Index, ModuleSpecifierEnding.JsExtension];
+            }
+            switch (preferredEnding) {
+                case ModuleSpecifierEnding.JsExtension: return [ModuleSpecifierEnding.JsExtension, ModuleSpecifierEnding.Minimal, ModuleSpecifierEnding.Index];
+                case ModuleSpecifierEnding.TsExtension: return [ModuleSpecifierEnding.TsExtension, ModuleSpecifierEnding.Minimal, ModuleSpecifierEnding.JsExtension, ModuleSpecifierEnding.Index];
+                case ModuleSpecifierEnding.Index: return [ModuleSpecifierEnding.Index, ModuleSpecifierEnding.Minimal, ModuleSpecifierEnding.JsExtension];
+                case ModuleSpecifierEnding.Minimal: return [ModuleSpecifierEnding.Minimal, ModuleSpecifierEnding.Index, ModuleSpecifierEnding.JsExtension];
+                default: Debug.assertNever(preferredEnding);
+            }
+        },
     };
-}
 
-function isFormatRequiringExtensions(compilerOptions: CompilerOptions, importingSourceFileName: Path, host: ModuleSpecifierResolutionHost) {
-    if (getEmitModuleResolutionKind(compilerOptions) !== ModuleResolutionKind.Node16
-    && getEmitModuleResolutionKind(compilerOptions) !== ModuleResolutionKind.NodeNext) {
-        return false;
+    function getPreferredEnding(): ModuleSpecifierEnding {
+        if (oldImportSpecifier !== undefined) {
+            if (hasJSFileExtension(oldImportSpecifier)) return ModuleSpecifierEnding.JsExtension;
+            if (endsWith(oldImportSpecifier, "/index")) return ModuleSpecifierEnding.Index;
+        }
+        return getModuleSpecifierEndingPreference(
+            importModuleSpecifierEnding,
+            importingSourceFile.impliedNodeFormat,
+            compilerOptions,
+            importingSourceFile);
     }
-    return getImpliedNodeFormatForFile(importingSourceFileName, host.getPackageJsonInfoCache?.(), getModuleResolutionHost(host), compilerOptions) !== ModuleKind.CommonJS;
-}
-
-function getModuleResolutionHost(host: ModuleSpecifierResolutionHost): ModuleResolutionHost {
-    return {
-        fileExists: host.fileExists,
-        readFile: Debug.checkDefined(host.readFile),
-        directoryExists: host.directoryExists,
-        getCurrentDirectory: host.getCurrentDirectory,
-        realpath: host.realpath,
-        useCaseSensitiveFileNames: host.useCaseSensitiveFileNames?.(),
-    };
 }
 
 // `importingSourceFile` and `importingSourceFileName`? Why not just use `importingSourceFile.path`?
@@ -178,7 +182,7 @@ export function updateModuleSpecifier(
     oldImportSpecifier: string,
     options: ModuleSpecifierOptions = {},
 ): string | undefined {
-    const res = getModuleSpecifierWorker(compilerOptions, importingSourceFile, importingSourceFileName, toFileName, host, getPreferencesForUpdate(compilerOptions, oldImportSpecifier, importingSourceFileName, host), {}, options);
+    const res = getModuleSpecifierWorker(compilerOptions, importingSourceFile, importingSourceFileName, toFileName, host, getPreferences({}, compilerOptions, importingSourceFile, oldImportSpecifier), {}, options);
     if (res === oldImportSpecifier) return undefined;
     return res;
 }
@@ -198,7 +202,7 @@ export function getModuleSpecifier(
     host: ModuleSpecifierResolutionHost,
     options: ModuleSpecifierOptions = {},
 ): string {
-    return getModuleSpecifierWorker(compilerOptions, importingSourceFile, importingSourceFileName, toFileName, host, getPreferences(host, {}, compilerOptions, importingSourceFile), {}, options);
+    return getModuleSpecifierWorker(compilerOptions, importingSourceFile, importingSourceFileName, toFileName, host, getPreferences({}, compilerOptions, importingSourceFile), {}, options);
 }
 
 /** @internal */
@@ -331,7 +335,7 @@ function computeModuleSpecifiers(
     options: ModuleSpecifierOptions = {},
 ): readonly string[] {
     const info = getInfo(importingSourceFile.path, host);
-    const preferences = getPreferences(host, userPreferences, compilerOptions, importingSourceFile);
+    const preferences = getPreferences(userPreferences, compilerOptions, importingSourceFile);
     const existingSpecifier = forEach(modulePaths, modulePath => forEach(
         host.getFileIncludeReasons().get(toPath(modulePath.path, host.getCurrentDirectory(), info.getCanonicalFileName)),
         reason => {
@@ -423,17 +427,18 @@ function getInfo(importingSourceFileName: Path, host: ModuleSpecifierResolutionH
     return { getCanonicalFileName, importingSourceFileName, sourceDirectory };
 }
 
-function getLocalModuleSpecifier(moduleFileName: string, info: Info, compilerOptions: CompilerOptions, host: ModuleSpecifierResolutionHost, importMode: ResolutionMode, { ending, relativePreference }: Preferences): string;
-function getLocalModuleSpecifier(moduleFileName: string, info: Info, compilerOptions: CompilerOptions, host: ModuleSpecifierResolutionHost, importMode: ResolutionMode, { ending, relativePreference }: Preferences, pathsOnly?: boolean): string | undefined;
-function getLocalModuleSpecifier(moduleFileName: string, info: Info, compilerOptions: CompilerOptions, host: ModuleSpecifierResolutionHost, importMode: ResolutionMode, { ending, relativePreference }: Preferences, pathsOnly?: boolean): string | undefined {
+function getLocalModuleSpecifier(moduleFileName: string, info: Info, compilerOptions: CompilerOptions, host: ModuleSpecifierResolutionHost, importMode: ResolutionMode, preferences: Preferences): string;
+function getLocalModuleSpecifier(moduleFileName: string, info: Info, compilerOptions: CompilerOptions, host: ModuleSpecifierResolutionHost, importMode: ResolutionMode, preferences: Preferences, pathsOnly?: boolean): string | undefined;
+function getLocalModuleSpecifier(moduleFileName: string, info: Info, compilerOptions: CompilerOptions, host: ModuleSpecifierResolutionHost, importMode: ResolutionMode, { getAllowedEndingsInPreferredOrder: getAllowedEndingsInPrefererredOrder, relativePreference }: Preferences, pathsOnly?: boolean): string | undefined {
     const { baseUrl, paths, rootDirs } = compilerOptions;
     if (pathsOnly && !paths) {
         return undefined;
     }
 
     const { sourceDirectory, getCanonicalFileName } = info;
-    const relativePath = rootDirs && tryGetModuleNameFromRootDirs(rootDirs, moduleFileName, sourceDirectory, getCanonicalFileName, ending, compilerOptions) ||
-        removeExtensionAndIndexPostFix(ensurePathIsNonModuleName(getRelativePathFromDirectory(sourceDirectory, moduleFileName, getCanonicalFileName)), ending, compilerOptions);
+    const allowedEndings = getAllowedEndingsInPrefererredOrder(importMode);
+    const relativePath = rootDirs && tryGetModuleNameFromRootDirs(rootDirs, moduleFileName, sourceDirectory, getCanonicalFileName, allowedEndings, compilerOptions) ||
+        processEnding(ensurePathIsNonModuleName(getRelativePathFromDirectory(sourceDirectory, moduleFileName, getCanonicalFileName)), allowedEndings, compilerOptions);
     if (!baseUrl && !paths || relativePreference === RelativePreference.Relative) {
         return pathsOnly ? undefined : relativePath;
     }
@@ -444,12 +449,12 @@ function getLocalModuleSpecifier(moduleFileName: string, info: Info, compilerOpt
         return pathsOnly ? undefined : relativePath;
     }
 
-    const fromPaths = paths && tryGetModuleNameFromPaths(relativeToBaseUrl, paths, getAllowedEndings(ending, compilerOptions, importMode), host, compilerOptions);
+    const fromPaths = paths && tryGetModuleNameFromPaths(relativeToBaseUrl, paths, allowedEndings, host, compilerOptions);
     if (pathsOnly) {
         return fromPaths;
     }
 
-    const maybeNonRelative = fromPaths === undefined && baseUrl !== undefined ? removeExtensionAndIndexPostFix(relativeToBaseUrl, ending, compilerOptions) : fromPaths;
+    const maybeNonRelative = fromPaths === undefined && baseUrl !== undefined ? processEnding(relativeToBaseUrl, allowedEndings, compilerOptions) : fromPaths;
     if (!maybeNonRelative) {
         return relativePath;
     }
@@ -508,10 +513,6 @@ export function countPathComponents(path: string): number {
     return count;
 }
 
-function usesJsExtensionOnImports({ imports }: SourceFile): boolean {
-    return firstDefined(imports, ({ text }) => pathIsRelative(text) ? hasJSFileExtension(text) : undefined) || false;
-}
-
 function comparePathsByRedirectAndNumberOfDirectorySeparators(a: ModulePath, b: ModulePath) {
     return compareBooleans(b.isRedirect, a.isRedirect) || compareNumberOfDirectorySeparators(a.path, b.path);
 }
@@ -698,19 +699,7 @@ function tryGetModuleNameFromAmbientModule(moduleSymbol: Symbol, checker: TypeCh
     }
 }
 
-function getAllowedEndings(preferredEnding: Ending, compilerOptions: CompilerOptions, importMode: ResolutionMode) {
-    if (getEmitModuleResolutionKind(compilerOptions) >= ModuleResolutionKind.Node16 && importMode === ModuleKind.ESNext) {
-        return [Ending.JsExtension];
-    }
-    switch (preferredEnding) {
-        case Ending.JsExtension: return [Ending.JsExtension, Ending.Minimal, Ending.Index];
-        case Ending.Index: return [Ending.Index, Ending.Minimal, Ending.JsExtension];
-        case Ending.Minimal: return [Ending.Minimal, Ending.Index, Ending.JsExtension];
-        default: Debug.assertNever(preferredEnding);
-    }
-}
-
-function tryGetModuleNameFromPaths(relativeToBaseUrl: string, paths: MapLike<readonly string[]>, allowedEndings: Ending[], host: ModuleSpecifierResolutionHost, compilerOptions: CompilerOptions): string | undefined {
+function tryGetModuleNameFromPaths(relativeToBaseUrl: string, paths: MapLike<readonly string[]>, allowedEndings: ModuleSpecifierEnding[], host: ModuleSpecifierResolutionHost, compilerOptions: CompilerOptions): string | undefined {
     for (const key in paths) {
         for (const patternText of paths[key]) {
             const pattern = normalizePath(patternText);
@@ -751,9 +740,9 @@ function tryGetModuleNameFromPaths(relativeToBaseUrl: string, paths: MapLike<rea
             // resolution, but as long criteria (b) above is met, I don't think its result needs to be the highest priority result
             // in module specifier generation. I have included it last, as it's difficult to tell exactly where it should be
             // sorted among the others for a particular value of `importModuleSpecifierEnding`.
-            const candidates: { ending: Ending | undefined, value: string }[] = allowedEndings.map(ending => ({
+            const candidates: { ending: ModuleSpecifierEnding | undefined, value: string }[] = allowedEndings.map(ending => ({
                 ending,
-                value: removeExtensionAndIndexPostFix(relativeToBaseUrl, ending, compilerOptions)
+                value: processEnding(relativeToBaseUrl, [ending], compilerOptions)
             }));
             if (tryGetExtensionFromPath(pattern)) {
                 candidates.push({ ending: undefined, value: relativeToBaseUrl });
@@ -774,23 +763,23 @@ function tryGetModuleNameFromPaths(relativeToBaseUrl: string, paths: MapLike<rea
                 }
             }
             else if (
-                some(candidates, c => c.ending !== Ending.Minimal && pattern === c.value) ||
-                some(candidates, c => c.ending === Ending.Minimal && pattern === c.value && validateEnding(c))
+                some(candidates, c => c.ending !== ModuleSpecifierEnding.Minimal && pattern === c.value) ||
+                some(candidates, c => c.ending === ModuleSpecifierEnding.Minimal && pattern === c.value && validateEnding(c))
             ) {
                 return key;
             }
         }
     }
 
-    function validateEnding({ ending, value }: { ending: Ending | undefined, value: string }) {
+    function validateEnding({ ending, value }: { ending: ModuleSpecifierEnding | undefined, value: string }) {
         // Optimization: `removeExtensionAndIndexPostFix` can query the file system (a good bit) if `ending` is `Minimal`, the basename
         // is 'index', and a `host` is provided. To avoid that until it's unavoidable, we ran the function with no `host` above. Only
         // here, after we've checked that the minimal ending is indeed a match (via the length and prefix/suffix checks / `some` calls),
         // do we check that the host-validated result is consistent with the answer we got before. If it's not, it falls back to the
-        // `Ending.Index` result, which should already be in the list of candidates if `Minimal` was. (Note: the assumption here is
+        // `ModuleSpecifierEnding.Index` result, which should already be in the list of candidates if `Minimal` was. (Note: the assumption here is
         // that every module resolution mode that supports dropping extensions also supports dropping `/index`. Like literally
         // everything else in this file, this logic needs to be updated if that's not true in some future module resolution mode.)
-        return ending !== Ending.Minimal || value === removeExtensionAndIndexPostFix(relativeToBaseUrl, ending, compilerOptions, host);
+        return ending !== ModuleSpecifierEnding.Minimal || value === processEnding(relativeToBaseUrl, [ending], compilerOptions, host);
     }
 }
 
@@ -865,7 +854,7 @@ function tryGetModuleNameFromExports(options: CompilerOptions, targetFilePath: s
     return undefined;
 }
 
-function tryGetModuleNameFromRootDirs(rootDirs: readonly string[], moduleFileName: string, sourceDirectory: string, getCanonicalFileName: (file: string) => string, ending: Ending, compilerOptions: CompilerOptions): string | undefined {
+function tryGetModuleNameFromRootDirs(rootDirs: readonly string[], moduleFileName: string, sourceDirectory: string, getCanonicalFileName: (file: string) => string, allowedEndings: readonly ModuleSpecifierEnding[], compilerOptions: CompilerOptions): string | undefined {
     const normalizedTargetPaths = getPathsRelativeToRootDirs(moduleFileName, rootDirs, getCanonicalFileName);
     if (normalizedTargetPaths === undefined) {
         return undefined;
@@ -879,10 +868,7 @@ function tryGetModuleNameFromRootDirs(rootDirs: readonly string[], moduleFileNam
     if (!shortest) {
         return undefined;
     }
-
-    return getEmitModuleResolutionKind(compilerOptions) === ModuleResolutionKind.Classic
-        ? removeFileExtension(shortest)
-        : removeExtensionAndIndexPostFix(shortest, ending, compilerOptions);
+    return processEnding(shortest, allowedEndings, compilerOptions);
 }
 
 function tryGetModuleNameAsNodeModule({ path, isRedirect }: ModulePath, { getCanonicalFileName, sourceDirectory }: Info, importingSourceFile: SourceFile, host: ModuleSpecifierResolutionHost, options: CompilerOptions, userPreferences: UserPreferences, packageNameOnly?: boolean, overrideMode?: ResolutionMode): string | undefined {
@@ -896,7 +882,8 @@ function tryGetModuleNameAsNodeModule({ path, isRedirect }: ModulePath, { getCan
 
     // Simplify the full file path to something that can be resolved by Node.
 
-    const preferences = getPreferences(host, userPreferences, options, importingSourceFile);
+    const preferences = getPreferences(userPreferences, options, importingSourceFile);
+    const allowedEndings = preferences.getAllowedEndingsInPreferredOrder();
     let moduleSpecifier = path;
     let isPackageRootPath = false;
     if (!packageNameOnly) {
@@ -923,7 +910,7 @@ function tryGetModuleNameAsNodeModule({ path, isRedirect }: ModulePath, { getCan
             // try with next level of directory
             packageRootIndex = path.indexOf(directorySeparator, packageRootIndex + 1);
             if (packageRootIndex === -1) {
-                moduleSpecifier = removeExtensionAndIndexPostFix(moduleFileName, preferences.ending, options, host);
+                moduleSpecifier = processEnding(moduleFileName, allowedEndings, options, host);
                 break;
             }
         }
@@ -979,7 +966,7 @@ function tryGetModuleNameAsNodeModule({ path, isRedirect }: ModulePath, { getCan
                 const fromPaths = tryGetModuleNameFromPaths(
                     subModuleName,
                     versionPaths.paths,
-                    getAllowedEndings(preferences.ending, options, importMode),
+                    allowedEndings,
                     host,
                     options
                 );
@@ -1036,13 +1023,22 @@ function getPathsRelativeToRootDirs(path: string, rootDirs: readonly string[], g
     });
 }
 
-function removeExtensionAndIndexPostFix(fileName: string, ending: Ending, options: CompilerOptions, host?: ModuleSpecifierResolutionHost): string {
-    if (fileExtensionIsOneOf(fileName, [Extension.Json, Extension.Mjs, Extension.Cjs])) return fileName;
+function processEnding(fileName: string, allowedEndings: readonly ModuleSpecifierEnding[], options: CompilerOptions, host?: ModuleSpecifierResolutionHost): string {
+    if (fileExtensionIsOneOf(fileName, [Extension.Json, Extension.Mjs, Extension.Cjs])) {
+        return fileName;
+    }
+
     const noExtension = removeFileExtension(fileName);
-    if (fileName === noExtension) return fileName;
-    if (fileExtensionIsOneOf(fileName, [Extension.Dmts, Extension.Mts, Extension.Dcts, Extension.Cts])) return noExtension + getJSExtensionForFile(fileName, options);
-    switch (ending) {
-        case Ending.Minimal:
+    if (fileName === noExtension) {
+        return fileName;
+    }
+
+    if (fileExtensionIsOneOf(fileName, [Extension.Dmts, Extension.Mts, Extension.Dcts, Extension.Cts])) {
+        return noExtension + getJSExtensionForFile(fileName, options);
+    }
+
+    switch (allowedEndings[0]) {
+        case ModuleSpecifierEnding.Minimal:
             const withoutIndex = removeSuffix(noExtension, "/index");
             if (host && withoutIndex !== noExtension && tryGetAnyFileFromPath(host, withoutIndex)) {
                 // Can't remove index if there's a file by the same name as the directory.
@@ -1050,12 +1046,23 @@ function removeExtensionAndIndexPostFix(fileName: string, ending: Ending, option
                 return noExtension;
             }
             return withoutIndex;
-        case Ending.Index:
+        case ModuleSpecifierEnding.Index:
             return noExtension;
-        case Ending.JsExtension:
+        case ModuleSpecifierEnding.JsExtension:
             return noExtension + getJSExtensionForFile(fileName, options);
+        case ModuleSpecifierEnding.TsExtension:
+            // For now, we don't know if this import is going to be type-only, which means we don't
+            // know if a .d.ts extension is valid, so use no extension or a .js extension
+            if (isDeclarationFileName(fileName)) {
+                const extensionlessPriority = allowedEndings.findIndex(e => e === ModuleSpecifierEnding.Minimal || e === ModuleSpecifierEnding.Index);
+                const jsPriority = allowedEndings.indexOf(ModuleSpecifierEnding.JsExtension);
+                return extensionlessPriority !== -1 && extensionlessPriority < jsPriority
+                    ? noExtension
+                    : noExtension + getJSExtensionForFile(fileName, options);
+            }
+            return fileName;
         default:
-            return Debug.assertNever(ending);
+            return Debug.assertNever(allowedEndings[0]);
     }
 }
 
diff --git a/src/compiler/program.ts b/src/compiler/program.ts
index 5cefcfdda324f..ee27160a182e9 100644
--- a/src/compiler/program.ts
+++ b/src/compiler/program.ts
@@ -132,6 +132,7 @@ import {
     getPropertyArrayElementValue,
     getPropertyAssignment,
     getResolvedModule,
+    getResolveJsonModule,
     getRootLength,
     getSetExternalModuleIndicator,
     getSpellingSuggestion,
@@ -215,6 +216,8 @@ import {
     ModuleResolutionHost,
     moduleResolutionIsEqualTo,
     ModuleResolutionKind,
+    moduleResolutionSupportsPackageJsonExportsAndImports,
+    moduleResolutionSupportsResolvingTsExtensions,
     Mutable,
     Node,
     NodeArray,
@@ -3158,7 +3161,10 @@ export function createProgram(rootNamesOrOptions: readonly string[] | CreateProg
         for (const node of file.statements) {
             collectModuleReferences(node, /*inAmbientModule*/ false);
         }
-        if ((file.flags & NodeFlags.PossiblyContainsDynamicImport) || isJavaScriptFile) {
+
+        // `require` has no special meaning in `--moduleResolution bundler`
+        const shouldProcessRequires = isJavaScriptFile && getEmitModuleResolutionKind(options) !== ModuleResolutionKind.Bundler;
+        if ((file.flags & NodeFlags.PossiblyContainsDynamicImport) || shouldProcessRequires) {
             collectDynamicImportOrRequireCalls(file);
         }
 
@@ -3220,7 +3226,7 @@ export function createProgram(rootNamesOrOptions: readonly string[] | CreateProg
             const r = /import|require/g;
             while (r.exec(file.text) !== null) { // eslint-disable-line no-null/no-null
                 const node = getNodeAtPosition(file, r.lastIndex);
-                if (isJavaScriptFile && isRequireCall(node, /*checkArgumentIsStringLiteralLike*/ true)) {
+                if (shouldProcessRequires && isRequireCall(node, /*checkArgumentIsStringLiteralLike*/ true)) {
                     setParentRecursive(node, /*incremental*/ false); // we need parent data on imports before the program is fully bound, so we ensure it's set here
                     imports = append(imports, node.arguments[0]);
                 }
@@ -4111,10 +4117,11 @@ export function createProgram(rootNamesOrOptions: readonly string[] | CreateProg
             }
         }
 
-        if (options.resolveJsonModule) {
+        if (getResolveJsonModule(options)) {
             if (getEmitModuleResolutionKind(options) !== ModuleResolutionKind.NodeJs &&
                 getEmitModuleResolutionKind(options) !== ModuleResolutionKind.Node16 &&
-                getEmitModuleResolutionKind(options) !== ModuleResolutionKind.NodeNext) {
+                getEmitModuleResolutionKind(options) !== ModuleResolutionKind.NodeNext &&
+                getEmitModuleResolutionKind(options) !== ModuleResolutionKind.Bundler) {
                 createDiagnosticForOptionName(Diagnostics.Option_resolveJsonModule_cannot_be_specified_without_node_module_resolution_strategy, "resolveJsonModule");
             }
             // Any emit other than common js, amd, es2015 or esnext is error
@@ -4205,6 +4212,21 @@ export function createProgram(rootNamesOrOptions: readonly string[] | CreateProg
             createOptionValueDiagnostic("importsNotUsedAsValues", Diagnostics.Option_preserveValueImports_can_only_be_used_when_module_is_set_to_es2015_or_later);
         }
 
+        if (options.allowImportingTsExtensions && !(moduleResolutionSupportsResolvingTsExtensions(options) && (options.noEmit || options.emitDeclarationOnly))) {
+            createOptionValueDiagnostic("allowImportingTsExtensions", Diagnostics.Option_allowImportingTsExtensions_can_only_be_used_when_moduleResolution_is_set_to_bundler_and_either_noEmit_or_emitDeclarationOnly_is_set);
+        }
+
+        const moduleResolution = getEmitModuleResolutionKind(options);
+        if (options.resolvePackageJsonExports && !moduleResolutionSupportsPackageJsonExportsAndImports(moduleResolution)) {
+            createOptionValueDiagnostic("resolvePackageJsonExports", Diagnostics.Option_0_can_only_be_used_when_moduleResolution_is_set_to_node16_nodenext_or_bundler, "resolvePackageJsonExports");
+        }
+        if (options.resolvePackageJsonImports && !moduleResolutionSupportsPackageJsonExportsAndImports(moduleResolution)) {
+            createOptionValueDiagnostic("resolvePackageJsonImports", Diagnostics.Option_0_can_only_be_used_when_moduleResolution_is_set_to_node16_nodenext_or_bundler, "resolvePackageJsonImports");
+        }
+        if (options.customConditions && !moduleResolutionSupportsPackageJsonExportsAndImports(moduleResolution)) {
+            createOptionValueDiagnostic("customConditions", Diagnostics.Option_0_can_only_be_used_when_moduleResolution_is_set_to_node16_nodenext_or_bundler, "customConditions");
+        }
+
         // If the emit is enabled make sure that every output file is unique and not overwriting any of the input files
         if (!options.noEmit && !options.suppressOutputPathCheck) {
             const emitHost = getEmitHost();
@@ -4900,7 +4922,7 @@ export function getResolutionDiagnostic(options: CompilerOptions, { extension }:
         return getAllowJSCompilerOption(options) || !getStrictOptionValue(options, "noImplicitAny") ? undefined : Diagnostics.Could_not_find_a_declaration_file_for_module_0_1_implicitly_has_an_any_type;
     }
     function needResolveJsonModule() {
-        return options.resolveJsonModule ? undefined : Diagnostics.Module_0_was_resolved_to_1_but_resolveJsonModule_is_not_used;
+        return getResolveJsonModule(options) ? undefined : Diagnostics.Module_0_was_resolved_to_1_but_resolveJsonModule_is_not_used;
     }
 }
 
diff --git a/src/compiler/types.ts b/src/compiler/types.ts
index 773d64df907ae..52cd88091726b 100644
--- a/src/compiler/types.ts
+++ b/src/compiler/types.ts
@@ -6886,6 +6886,7 @@ export enum ModuleResolutionKind {
     // In turn, we offer both a `NodeNext` moving resolution target, and a `Node16` version-anchored resolution target
     Node16   = 3,
     NodeNext = 99, // Not simply `Node16` so that compiled code linked against TS can use the `Next` value reliably (same as with `ModuleKind`)
+    Bundler   = 100,
 }
 
 export enum ModuleDetectionKind {
@@ -6945,6 +6946,7 @@ export type CompilerOptionsValue = string | number | boolean | (string | number)
 
 export interface CompilerOptions {
     /** @internal */ all?: boolean;
+    allowImportingTsExtensions?: boolean;
     allowJs?: boolean;
     /** @internal */ allowNonTsExtensions?: boolean;
     allowSyntheticDefaultImports?: boolean;
@@ -6968,6 +6970,7 @@ export interface CompilerOptions {
      * @internal
      */
     readonly configFile?: TsConfigSourceFile;
+    customConditions?: string[];
     declaration?: boolean;
     declarationMap?: boolean;
     emitDeclarationOnly?: boolean;
@@ -7054,6 +7057,8 @@ export interface CompilerOptions {
     incremental?: boolean;
     tsBuildInfoFile?: string;
     removeComments?: boolean;
+    resolvePackageJsonExports?: boolean;
+    resolvePackageJsonImports?: boolean;
     rootDir?: string;
     rootDirs?: string[];
     skipLibCheck?: boolean;
@@ -7501,6 +7506,11 @@ export interface ResolvedModule {
     resolvedFileName: string;
     /** True if `resolvedFileName` comes from `node_modules`. */
     isExternalLibraryImport?: boolean;
+    /**
+     * True if the original module reference used a .ts extension to refer directly to a .ts file,
+     * which should produce an error during checking if emit is enabled.
+     */
+    resolvedUsingTsExtension?: boolean;
 }
 
 /**
diff --git a/src/compiler/utilities.ts b/src/compiler/utilities.ts
index 5c65c652db3ef..4f69ae16f98a5 100644
--- a/src/compiler/utilities.ts
+++ b/src/compiler/utilities.ts
@@ -11,6 +11,7 @@ import {
     AnyImportOrReExport,
     AnyImportSyntax,
     AnyValidImportOrReExport,
+    append,
     arrayFrom,
     ArrayLiteralExpression,
     ArrayTypeNode,
@@ -441,6 +442,7 @@ import {
     semanticDiagnosticsOptionDeclarations,
     SetAccessorDeclaration,
     ShorthandPropertyAssignment,
+    shouldAllowImportingTsExtension,
     Signature,
     SignatureDeclaration,
     SignatureFlags,
@@ -513,6 +515,7 @@ import {
     TypeReferenceNode,
     unescapeLeadingUnderscores,
     UnionOrIntersectionTypeNode,
+    UserPreferences,
     ValidImportTypeNode,
     VariableDeclaration,
     VariableDeclarationInitializedTo,
@@ -7693,6 +7696,10 @@ export function getEmitModuleKind(compilerOptions: {module?: CompilerOptions["mo
         getEmitScriptTarget(compilerOptions) >= ScriptTarget.ES2015 ? ModuleKind.ES2015 : ModuleKind.CommonJS;
 }
 
+export function emitModuleKindIsNonNodeESM(moduleKind: ModuleKind) {
+    return moduleKind >= ModuleKind.ES2015 && moduleKind <= ModuleKind.ESNext;
+}
+
 /** @internal */
 export function getEmitModuleResolutionKind(compilerOptions: CompilerOptions) {
     let moduleResolution = compilerOptions.moduleResolution;
@@ -7768,11 +7775,62 @@ export function getESModuleInterop(compilerOptions: CompilerOptions) {
 
 /** @internal */
 export function getAllowSyntheticDefaultImports(compilerOptions: CompilerOptions) {
-    const moduleKind = getEmitModuleKind(compilerOptions);
-    return compilerOptions.allowSyntheticDefaultImports !== undefined
-        ? compilerOptions.allowSyntheticDefaultImports
-        : getESModuleInterop(compilerOptions) ||
-        moduleKind === ModuleKind.System;
+    if (compilerOptions.allowSyntheticDefaultImports !== undefined) {
+        return compilerOptions.allowSyntheticDefaultImports;
+    }
+    return getESModuleInterop(compilerOptions)
+        || getEmitModuleKind(compilerOptions) === ModuleKind.System
+        || getEmitModuleResolutionKind(compilerOptions) === ModuleResolutionKind.Bundler;
+}
+
+/** @internal */
+export function moduleResolutionSupportsPackageJsonExportsAndImports(moduleResolution: ModuleResolutionKind): boolean {
+    return moduleResolution >= ModuleResolutionKind.Node16 && moduleResolution <= ModuleResolutionKind.NodeNext
+        || moduleResolution === ModuleResolutionKind.Bundler;
+}
+
+/** @internal */
+export function getResolvePackageJsonExports(compilerOptions: CompilerOptions) {
+    const moduleResolution = getEmitModuleResolutionKind(compilerOptions);
+    if (!moduleResolutionSupportsPackageJsonExportsAndImports(moduleResolution)) {
+        return false;
+    }
+    if (compilerOptions.resolvePackageJsonExports !== undefined) {
+        return compilerOptions.resolvePackageJsonExports;
+    }
+    switch (moduleResolution) {
+        case ModuleResolutionKind.Node16:
+        case ModuleResolutionKind.NodeNext:
+        case ModuleResolutionKind.Bundler:
+            return true;
+    }
+    return false;
+}
+
+/** @internal */
+export function getResolvePackageJsonImports(compilerOptions: CompilerOptions) {
+    const moduleResolution = getEmitModuleResolutionKind(compilerOptions);
+    if (!moduleResolutionSupportsPackageJsonExportsAndImports(moduleResolution)) {
+        return false;
+    }
+    if (compilerOptions.resolvePackageJsonExports !== undefined) {
+        return compilerOptions.resolvePackageJsonExports;
+    }
+    switch (moduleResolution) {
+        case ModuleResolutionKind.Node16:
+        case ModuleResolutionKind.NodeNext:
+        case ModuleResolutionKind.Bundler:
+            return true;
+    }
+    return false;
+}
+
+/** @internal */
+export function getResolveJsonModule(compilerOptions: CompilerOptions) {
+    if (compilerOptions.resolveJsonModule !== undefined) {
+        return compilerOptions.resolveJsonModule;
+    }
+    return getEmitModuleResolutionKind(compilerOptions) === ModuleResolutionKind.Bundler;
 }
 
 /** @internal */
@@ -8410,7 +8468,7 @@ export function getSupportedExtensionsWithJsonIfResolveJsonModule(options: Compi
 export function getSupportedExtensionsWithJsonIfResolveJsonModule(options: CompilerOptions | undefined, supportedExtensions: readonly string[][]): readonly string[][];
 /** @internal */
 export function getSupportedExtensionsWithJsonIfResolveJsonModule(options: CompilerOptions | undefined, supportedExtensions: readonly string[][]): readonly string[][] {
-    if (!options || !options.resolveJsonModule) return supportedExtensions;
+    if (!options || !getResolveJsonModule(options)) return supportedExtensions;
     if (supportedExtensions === allSupportedExtensions) return allSupportedExtensionsWithJson;
     if (supportedExtensions === supportedTSExtensions) return supportedTSExtensionsWithJson;
     return [...supportedExtensions, [Extension.Json]];
@@ -8430,6 +8488,92 @@ export function hasTSFileExtension(fileName: string): boolean {
     return some(supportedTSExtensionsFlat, extension => fileExtensionIs(fileName, extension));
 }
 
+/**
+ * @internal
+ * Corresponds to UserPreferences#importPathEnding
+ */
+export const enum ModuleSpecifierEnding {
+    Minimal,
+    Index,
+    JsExtension,
+    TsExtension,
+}
+
+/** @internal */
+export function usesExtensionsOnImports({ imports }: SourceFile, hasExtension: (text: string) => boolean = or(hasJSFileExtension, hasTSFileExtension)): boolean {
+    return firstDefined(imports, ({ text }) => pathIsRelative(text) ? hasExtension(text) : undefined) || false;
+}
+
+/** @internal */
+export function getModuleSpecifierEndingPreference(preference: UserPreferences["importModuleSpecifierEnding"], resolutionMode: ResolutionMode, compilerOptions: CompilerOptions, sourceFile: SourceFile): ModuleSpecifierEnding {
+    if (preference === "js" || resolutionMode === ModuleKind.ESNext) {
+        // Extensions are explicitly requested or required. Now choose between .js and .ts.
+        if (!shouldAllowImportingTsExtension(compilerOptions)) {
+            return ModuleSpecifierEnding.JsExtension;
+        }
+        // `allowImportingTsExtensions` is a strong signal, so use .ts unless the file
+        // already uses .js extensions and no .ts extensions.
+        return inferPreference() !== ModuleSpecifierEnding.JsExtension
+            ? ModuleSpecifierEnding.TsExtension
+            : ModuleSpecifierEnding.JsExtension;
+    }
+    if (preference === "minimal") {
+        return ModuleSpecifierEnding.Minimal;
+    }
+    if (preference === "index") {
+        return ModuleSpecifierEnding.Index;
+    }
+
+    // No preference was specified.
+    // Look at imports and/or requires to guess whether .js, .ts, or extensionless imports are preferred.
+    // N.B. that `Index` detection is not supported since it would require file system probing to do
+    // accurately, and more importantly, literally nobody wants `Index` and its existence is a mystery.
+    if (!shouldAllowImportingTsExtension(compilerOptions)) {
+        // If .ts imports are not valid, we only need to see one .js import to go with that.
+        return usesExtensionsOnImports(sourceFile) ? ModuleSpecifierEnding.JsExtension : ModuleSpecifierEnding.Minimal;
+    }
+
+    return inferPreference();
+
+    function inferPreference() {
+        let usesJsExtensions = false;
+        const specifiers = sourceFile.imports.length ? sourceFile.imports.map(i => i.text) :
+            isSourceFileJS(sourceFile) ? getRequiresAtTopOfFile(sourceFile).map(r => r.arguments[0].text) :
+            emptyArray;
+        for (const specifier of specifiers) {
+            if (pathIsRelative(specifier)) {
+                if (hasTSFileExtension(specifier)) {
+                    return ModuleSpecifierEnding.TsExtension;
+                }
+                if (hasJSFileExtension(specifier)) {
+                    usesJsExtensions = true;
+                }
+            }
+        }
+        return usesJsExtensions ? ModuleSpecifierEnding.JsExtension : ModuleSpecifierEnding.Minimal;
+    }
+}
+
+function getRequiresAtTopOfFile(sourceFile: SourceFile): readonly RequireOrImportCall[] {
+    let nonRequireStatementCount = 0;
+    let requires: RequireOrImportCall[] | undefined;
+    for (const statement of sourceFile.statements) {
+        if (nonRequireStatementCount > 3) {
+            break;
+        }
+        if (isRequireVariableStatement(statement)) {
+            requires = concatenate(requires, statement.declarationList.declarations.map(d => d.initializer));
+        }
+        else if (isExpressionStatement(statement) && isRequireCall(statement.expression, /*requireStringLiteralLikeArgument*/ true)) {
+            requires = append(requires, statement.expression);
+        }
+        else {
+            nonRequireStatementCount++;
+        }
+    }
+    return requires || emptyArray;
+}
+
 /** @internal */
 export function isSupportedSourceFileName(fileName: string, compilerOptions?: CompilerOptions, extraFileExtensions?: readonly FileExtensionInfo[]) {
     if (!fileName) return false;
diff --git a/src/harness/fourslashImpl.ts b/src/harness/fourslashImpl.ts
index ac7c0c40ad3b5..8a2a4c65390d5 100644
--- a/src/harness/fourslashImpl.ts
+++ b/src/harness/fourslashImpl.ts
@@ -804,18 +804,6 @@ export class TestState {
         });
     }
 
-    private renderMarkers(markers: { text: string, fileName: string, position: number }[]) {
-        const filesToDisplay = ts.deduplicate(markers.map(m => m.fileName), ts.equateValues);
-        return filesToDisplay.map(fileName => {
-            const markersToRender = markers.filter(m => m.fileName === fileName).sort((a, b) => b.position - a.position);
-            let fileContent = this.tryGetFileContent(fileName) || "";
-            for (const marker of markersToRender) {
-                fileContent = fileContent.slice(0, marker.position) + `\x1b[1;4m/*${marker.text}*/\x1b[0;31m` + fileContent.slice(marker.position);
-            }
-            return `// @Filename: ${fileName}\n${fileContent}`;
-        }).join("\n\n");
-    }
-
     private verifyDefinitionTextSpan(defs: ts.DefinitionInfoAndBoundSpan, startMarkerName: string) {
         const range = this.testData.ranges.find(range => this.markerName(range.marker!) === startMarkerName);
 
@@ -839,6 +827,22 @@ export class TestState {
         }
     }
 
+    private renderMarkers(markers: { text: string, fileName: string, position: number }[], useTerminalBoldSequence = true) {
+        const filesToDisplay = ts.deduplicate(markers.map(m => m.fileName), ts.equateValues);
+        return filesToDisplay.map(fileName => {
+            const markersToRender = markers.filter(m => m.fileName === fileName).sort((a, b) => b.position - a.position);
+            let fileContent = this.tryGetFileContent(fileName) || "";
+            for (const marker of markersToRender) {
+                fileContent = fileContent.slice(0, marker.position) + bold(`/*${marker.text}*/`) + fileContent.slice(marker.position);
+            }
+            return `// @Filename: ${fileName}\n${fileContent}`;
+        }).join("\n\n");
+
+        function bold(text: string) {
+            return useTerminalBoldSequence ? `\x1b[1;4m${text}\x1b[0;31m` : text;
+        }
+    }
+
     public verifyGetEmitOutputForCurrentFile(expected: string): void {
         const emit = this.languageService.getEmitOutput(this.activeFile.fileName);
         if (emit.outputFiles.length !== 1) {
@@ -3188,12 +3192,53 @@ export class TestState {
         if (!negative && !validBraceCompletion) {
             this.raiseError(`${position} is not a valid brace completion position for ${openingBrace}`);
         }
-
         if (negative && validBraceCompletion) {
             this.raiseError(`${position} is a valid brace completion position for ${openingBrace}`);
         }
     }
 
+    public baselineAutoImports(markerName: string, preferences?: ts.UserPreferences) {
+        const marker = this.getMarkerByName(markerName);
+        const baselineFile = this.getBaselineFileNameForContainingTestFile(`.baseline.md`);
+        const completionPreferences = {
+            includeCompletionsForModuleExports: true,
+            includeCompletionsWithInsertText: true,
+            allowIncompleteCompletions: true,
+            includeCompletionsWithSnippetText: true,
+            ...preferences
+        };
+
+        const ext = ts.getAnyExtensionFromPath(this.activeFile.fileName).slice(1);
+        const lang = ["mts", "cts"].includes(ext) ? "ts" : ext;
+        let baselineText = codeFence(this.renderMarkers([{ text: "|", fileName: marker.fileName, position: marker.position }], /*useTerminalBoldSequence*/ false), lang) + "\n\n";
+        this.goToMarker(marker);
+
+        const completions = this.getCompletionListAtCaret(completionPreferences)!;
+
+        const autoImportCompletions = completions.entries.filter(c => c.hasAction && c.source && c.sortText === ts.Completions.SortText.AutoImportSuggestions);
+        if (autoImportCompletions.length) {
+            baselineText += `## From completions\n\n${autoImportCompletions.map(c => `- \`${c.name}\` from \`"${c.source}"\``).join("\n")}\n\n`;
+            autoImportCompletions.forEach(c => {
+                const details = this.getCompletionEntryDetails(c.name, c.source, c.data, completionPreferences);
+                assert(details?.codeActions, `Entry '${c.name}' from "${c.source}" returned no code actions from completion details request`);
+                assert(details.codeActions.length === 1, `Entry '${c.name}' from "${c.source}" returned more than one code action`);
+                assert(details.codeActions[0].changes.length === 1, `Entry '${c.name}' from "${c.source}" returned a code action changing more than one file`);
+                assert(details.codeActions[0].changes[0].fileName === this.activeFile.fileName, `Entry '${c.name}' from "${c.source}" returned a code action changing a different file`);
+                const changes = details.codeActions[0].changes[0].textChanges;
+                const completionChange: ts.TextChange = { newText: c.insertText || c.name, span: c.replacementSpan || completions.optionalReplacementSpan || { start: marker.position, length: 0 } };
+                const sortedChanges = [...changes, completionChange].sort((a, b) => a.span.start - b.span.start);
+                let newFileContent = this.activeFile.content;
+                for (let i = sortedChanges.length - 1; i >= 0; i--) {
+                    newFileContent = newFileContent.substring(0, sortedChanges[i].span.start) + sortedChanges[i].newText + newFileContent.substring(sortedChanges[i].span.start + sortedChanges[i].span.length);
+                }
+                baselineText += codeFence(newFileContent, lang) + "\n\n";
+            });
+        }
+
+        // TODO: do codefixes too
+        Harness.Baseline.runBaseline(baselineFile, baselineText);
+    }
+
     public verifyJsxClosingTag(map: { [markerName: string]: ts.JsxClosingTagInfo | undefined }): void {
         for (const markerName in map) {
             this.goToMarker(markerName);
@@ -4605,10 +4650,10 @@ function rangesOfDiffBetweenTwoStrings(source: string, target: string) {
         else {
             ranges.push({ start: index - 1, length: 1 });
         }
-      }
-      else {
+        }
+        else {
             ranges.push({ start: index - 1, length: 1 });
-      }
+        }
     };
 
     for (let index = 0; index < Math.max(source.length, target.length); index++) {
@@ -4618,10 +4663,10 @@ function rangesOfDiffBetweenTwoStrings(source: string, target: string) {
     }
 
     return ranges;
-  }
+}
 
-  // Adds an _ when the source string and the target string have a whitespace difference
-  function highlightDifferenceBetweenStrings(source: string, target: string) {
+// Adds an _ when the source string and the target string have a whitespace difference
+function highlightDifferenceBetweenStrings(source: string, target: string) {
     const ranges = rangesOfDiffBetweenTwoStrings(source, target);
     let emTarget = target;
     ranges.forEach((range, index) => {
@@ -4633,8 +4678,12 @@ function rangesOfDiffBetweenTwoStrings(source: string, target: string) {
             range.start + 1 + additionalOffset,
             range.start + range.length + 1 + additionalOffset
         );
-         const after = emTarget.slice(range.start + range.length + 1 + additionalOffset, emTarget.length);
+        const after = emTarget.slice(range.start + range.length + 1 + additionalOffset, emTarget.length);
         emTarget = before + lhs + between + rhs + after;
     });
     return emTarget;
-  }
+}
+
+function codeFence(code: string, lang?: string) {
+    return `\`\`\`${lang || ""}\n${code}\n\`\`\``;
+}
diff --git a/src/harness/fourslashInterfaceImpl.ts b/src/harness/fourslashInterfaceImpl.ts
index af1044d6fee6b..b71d67b530d8a 100644
--- a/src/harness/fourslashInterfaceImpl.ts
+++ b/src/harness/fourslashInterfaceImpl.ts
@@ -488,6 +488,10 @@ export class Verify extends VerifyNegatable {
         this.state.verifyImportFixModuleSpecifiers(marker, moduleSpecifiers, preferences);
     }
 
+    public baselineAutoImports(marker: string, preferences?: ts.UserPreferences) {
+        this.state.baselineAutoImports(marker, preferences);
+    }
+
     public navigationBar(json: any, options?: { checkSpans?: boolean }) {
         this.state.verifyNavigationBar(json, options);
     }
diff --git a/src/services/codefixes/importFixes.ts b/src/services/codefixes/importFixes.ts
index 2f0c90737549a..1b753b8942dde 100644
--- a/src/services/codefixes/importFixes.ts
+++ b/src/services/codefixes/importFixes.ts
@@ -814,7 +814,8 @@ function getNewImportFixes(
     const compilerOptions = program.getCompilerOptions();
     const moduleSpecifierResolutionHost = createModuleSpecifierResolutionHost(program, host);
     const getChecker = createGetChecker(program, host);
-    const rejectNodeModulesRelativePaths = moduleResolutionUsesNodeModules(getEmitModuleResolutionKind(compilerOptions));
+    const moduleResolution = getEmitModuleResolutionKind(compilerOptions);
+    const rejectNodeModulesRelativePaths = moduleResolutionUsesNodeModules(moduleResolution);
     const getModuleSpecifiers = fromCacheOnly
         ? (moduleSymbol: Symbol) => ({ moduleSpecifiers: moduleSpecifiers.tryGetModuleSpecifiersFromCache(moduleSymbol, sourceFile, moduleSpecifierResolutionHost, preferences), computedWithoutCache: false })
         : (moduleSymbol: Symbol, checker: TypeChecker) => moduleSpecifiers.getModuleSpecifiersWithCacheInfo(moduleSymbol, checker, compilerOptions, sourceFile, moduleSpecifierResolutionHost, preferences);
diff --git a/src/services/completions.ts b/src/services/completions.ts
index 6e02fd1e567a4..c451f7cf29fed 100644
--- a/src/services/completions.ts
+++ b/src/services/completions.ts
@@ -269,7 +269,7 @@ import {
     modifierToFlag,
     ModuleDeclaration,
     ModuleReference,
-    moduleResolutionRespectsExports,
+    moduleResolutionSupportsPackageJsonExportsAndImports,
     NamedImportBindings,
     Node,
     NodeArray,
@@ -548,7 +548,7 @@ const enum KeywordCompletionFilters {
 
 const enum GlobalsSearch { Continue, Success, Fail }
 
-interface ModuleSpecifierResolutioContext {
+interface ModuleSpecifierResolutionContext {
     tryResolve: (exportInfo: readonly SymbolExportInfo[], symbolName: string, isFromAmbientModule: boolean) => ModuleSpecifierResolutionResult;
     resolvedAny: () => boolean;
     skippedAny: () => boolean;
@@ -569,7 +569,7 @@ function resolvingModuleSpecifiers<TReturn>(
     preferences: UserPreferences,
     isForImportStatementCompletion: boolean,
     isValidTypeOnlyUseSite: boolean,
-    cb: (context: ModuleSpecifierResolutioContext) => TReturn,
+    cb: (context: ModuleSpecifierResolutionContext) => TReturn,
 ): TReturn {
     const start = timestamp();
     // Under `--moduleResolution nodenext`, we have to resolve module specifiers up front, because
@@ -577,7 +577,7 @@ function resolvingModuleSpecifiers<TReturn>(
     // relative path into node_modules), and we want to filter those completions out entirely.
     // Import statement completions always need specifier resolution because the module specifier is
     // part of their `insertText`, not the `codeActions` creating edits away from the cursor.
-    const needsFullResolution = isForImportStatementCompletion || moduleResolutionRespectsExports(getEmitModuleResolutionKind(program.getCompilerOptions()));
+    const needsFullResolution = isForImportStatementCompletion || moduleResolutionSupportsPackageJsonExportsAndImports(getEmitModuleResolutionKind(program.getCompilerOptions()));
     let skippedAny = false;
     let ambientCount = 0;
     let resolvedCount = 0;
diff --git a/src/services/stringCompletions.ts b/src/services/stringCompletions.ts
index c319ad3b8e92a..18f8e17750e2c 100644
--- a/src/services/stringCompletions.ts
+++ b/src/services/stringCompletions.ts
@@ -49,10 +49,12 @@ import {
     getEmitModuleResolutionKind,
     getLeadingCommentRanges,
     getModeForUsageLocation,
+    getModuleSpecifierEndingPreference,
     getOwnKeys,
     getPackageJsonTypesVersionsPaths,
     getPathComponents,
     getReplacementSpanForContextToken,
+    getResolvePackageJsonExports,
     getSupportedExtensions,
     getSupportedExtensionsWithJsonIfResolveJsonModule,
     getTokenAtPosition,
@@ -89,7 +91,8 @@ import {
     mapDefined,
     MapLike,
     ModuleKind,
-    ModuleResolutionKind,
+    moduleResolutionUsesNodeModules,
+    ModuleSpecifierEnding,
     moduleSpecifiers,
     Node,
     normalizePath,
@@ -120,6 +123,7 @@ import {
     StringLiteralLike,
     StringLiteralType,
     stripQuotes,
+    supportedTSImplementationExtensions,
     Symbol,
     SyntaxKind,
     textPart,
@@ -525,49 +529,44 @@ function getStringLiteralCompletionsFromModuleNamesWorker(sourceFile: SourceFile
 
     const scriptPath = sourceFile.path;
     const scriptDirectory = getDirectoryPath(scriptPath);
+    const extensionOptions = getExtensionOptions(compilerOptions, ReferenceKind.ModuleSpecifier, sourceFile, preferences, mode);
 
     return isPathRelativeToScript(literalValue) || !compilerOptions.baseUrl && (isRootedDiskPath(literalValue) || isUrl(literalValue))
-        ? getCompletionEntriesForRelativeModules(literalValue, scriptDirectory, compilerOptions, host, scriptPath, getIncludeExtensionOption())
-        : getCompletionEntriesForNonRelativeModules(literalValue, scriptDirectory, mode, compilerOptions, host, getIncludeExtensionOption(), typeChecker);
-
-    function getIncludeExtensionOption() {
-        const mode = isStringLiteralLike(node) ? getModeForUsageLocation(sourceFile, node) : undefined;
-        return preferences.importModuleSpecifierEnding === "js" || mode === ModuleKind.ESNext ? IncludeExtensionsOption.ModuleSpecifierCompletion : IncludeExtensionsOption.Exclude;
-    }
+        ? getCompletionEntriesForRelativeModules(literalValue, scriptDirectory, compilerOptions, host, scriptPath, extensionOptions)
+        : getCompletionEntriesForNonRelativeModules(literalValue, scriptDirectory, mode, compilerOptions, host, extensionOptions, typeChecker);
 }
 
 interface ExtensionOptions {
-    readonly extensions: readonly Extension[];
-    readonly includeExtensionsOption: IncludeExtensionsOption;
+    readonly extensionsToSearch: readonly Extension[];
+    readonly referenceKind: ReferenceKind;
+    readonly importingSourceFile: SourceFile;
+    readonly endingPreference?: UserPreferences["importModuleSpecifierEnding"];
+    readonly resolutionMode?: ResolutionMode;
 }
-function getExtensionOptions(compilerOptions: CompilerOptions, includeExtensionsOption = IncludeExtensionsOption.Exclude): ExtensionOptions {
-    return { extensions: flatten(getSupportedExtensionsForModuleResolution(compilerOptions)), includeExtensionsOption };
+
+function getExtensionOptions(compilerOptions: CompilerOptions, referenceKind: ReferenceKind, importingSourceFile: SourceFile, preferences?: UserPreferences, resolutionMode?: ResolutionMode): ExtensionOptions {
+    return {
+        extensionsToSearch: flatten(getSupportedExtensionsForModuleResolution(compilerOptions)),
+        referenceKind,
+        importingSourceFile,
+        endingPreference: preferences?.importModuleSpecifierEnding,
+        resolutionMode,
+    };
 }
-function getCompletionEntriesForRelativeModules(literalValue: string, scriptDirectory: string, compilerOptions: CompilerOptions, host: LanguageServiceHost, scriptPath: Path, includeExtensions: IncludeExtensionsOption) {
-    const extensionOptions = getExtensionOptions(compilerOptions, includeExtensions);
+function getCompletionEntriesForRelativeModules(literalValue: string, scriptDirectory: string, compilerOptions: CompilerOptions, host: LanguageServiceHost, scriptPath: Path, extensionOptions: ExtensionOptions) {
     if (compilerOptions.rootDirs) {
         return getCompletionEntriesForDirectoryFragmentWithRootDirs(
             compilerOptions.rootDirs, literalValue, scriptDirectory, extensionOptions, compilerOptions, host, scriptPath);
     }
     else {
-        return arrayFrom(getCompletionEntriesForDirectoryFragment(literalValue, scriptDirectory, extensionOptions, host, scriptPath).values());
+        return arrayFrom(getCompletionEntriesForDirectoryFragment(literalValue, scriptDirectory, extensionOptions, host, /*moduleSpecifierIsRelative*/ false, scriptPath).values());
     }
 }
 
-function isEmitResolutionKindUsingNodeModules(compilerOptions: CompilerOptions): boolean {
-    return getEmitModuleResolutionKind(compilerOptions) === ModuleResolutionKind.NodeJs ||
-        getEmitModuleResolutionKind(compilerOptions) === ModuleResolutionKind.Node16 ||
-        getEmitModuleResolutionKind(compilerOptions) === ModuleResolutionKind.NodeNext;
-}
-
-function isEmitModuleResolutionRespectingExportMaps(compilerOptions: CompilerOptions) {
-    return getEmitModuleResolutionKind(compilerOptions) === ModuleResolutionKind.Node16 ||
-    getEmitModuleResolutionKind(compilerOptions) === ModuleResolutionKind.NodeNext;
-}
-
 function getSupportedExtensionsForModuleResolution(compilerOptions: CompilerOptions): readonly Extension[][] {
     const extensions = getSupportedExtensions(compilerOptions);
-    return isEmitResolutionKindUsingNodeModules(compilerOptions) ?
+    const moduleResolution = getEmitModuleResolutionKind(compilerOptions);
+    return moduleResolutionUsesNodeModules(moduleResolution) ?
         getSupportedExtensionsWithJsonIfResolveJsonModule(compilerOptions, extensions) :
         extensions;
 }
@@ -595,22 +594,22 @@ function getCompletionEntriesForDirectoryFragmentWithRootDirs(rootDirs: string[]
     const basePath = compilerOptions.project || host.getCurrentDirectory();
     const ignoreCase = !(host.useCaseSensitiveFileNames && host.useCaseSensitiveFileNames());
     const baseDirectories = getBaseDirectoriesFromRootDirs(rootDirs, basePath, scriptDirectory, ignoreCase);
-    return flatMap(baseDirectories, baseDirectory => arrayFrom(getCompletionEntriesForDirectoryFragment(fragment, baseDirectory, extensionOptions, host, exclude).values()));
+    return flatMap(baseDirectories, baseDirectory => arrayFrom(getCompletionEntriesForDirectoryFragment(fragment, baseDirectory, extensionOptions, host, /*moduleSpecifierIsRelative*/ true, exclude).values()));
 }
 
-const enum IncludeExtensionsOption {
-    Exclude,
-    Include,
-    ModuleSpecifierCompletion,
+const enum ReferenceKind {
+    Filename,
+    ModuleSpecifier,
 }
 /**
  * Given a path ending at a directory, gets the completions for the path, and filters for those entries containing the basename.
  */
 function getCompletionEntriesForDirectoryFragment(
     fragment: string,
-    scriptPath: string,
+    scriptDirectory: string,
     extensionOptions: ExtensionOptions,
     host: LanguageServiceHost,
+    moduleSpecifierIsRelative: boolean,
     exclude?: string,
     result = createNameAndKindSet()
 ): NameAndKindSet {
@@ -634,23 +633,25 @@ function getCompletionEntriesForDirectoryFragment(
 
     fragment = ensureTrailingDirectorySeparator(fragment);
 
-    const absolutePath = resolvePath(scriptPath, fragment);
+    const absolutePath = resolvePath(scriptDirectory, fragment);
     const baseDirectory = hasTrailingDirectorySeparator(absolutePath) ? absolutePath : getDirectoryPath(absolutePath);
 
-    // check for a version redirect
-    const packageJsonPath = findPackageJson(baseDirectory, host);
-    if (packageJsonPath) {
-        const packageJson = readJson(packageJsonPath, host as { readFile: (filename: string) => string | undefined });
-        const typesVersions = (packageJson as any).typesVersions;
-        if (typeof typesVersions === "object") {
-            const versionPaths = getPackageJsonTypesVersionsPaths(typesVersions)?.paths;
-            if (versionPaths) {
-                const packageDirectory = getDirectoryPath(packageJsonPath);
-                const pathInPackage = absolutePath.slice(ensureTrailingDirectorySeparator(packageDirectory).length);
-                if (addCompletionEntriesFromPaths(result, pathInPackage, packageDirectory, extensionOptions, host, versionPaths)) {
-                    // A true result means one of the `versionPaths` was matched, which will block relative resolution
-                    // to files and folders from here. All reachable paths given the pattern match are already added.
-                    return result;
+    if (!moduleSpecifierIsRelative) {
+        // check for a version redirect
+        const packageJsonPath = findPackageJson(baseDirectory, host);
+        if (packageJsonPath) {
+            const packageJson = readJson(packageJsonPath, host as { readFile: (filename: string) => string | undefined });
+            const typesVersions = (packageJson as any).typesVersions;
+            if (typeof typesVersions === "object") {
+                const versionPaths = getPackageJsonTypesVersionsPaths(typesVersions)?.paths;
+                if (versionPaths) {
+                    const packageDirectory = getDirectoryPath(packageJsonPath);
+                    const pathInPackage = absolutePath.slice(ensureTrailingDirectorySeparator(packageDirectory).length);
+                    if (addCompletionEntriesFromPaths(result, pathInPackage, packageDirectory, extensionOptions, host, versionPaths)) {
+                        // A true result means one of the `versionPaths` was matched, which will block relative resolution
+                        // to files and folders from here. All reachable paths given the pattern match are already added.
+                        return result;
+                    }
                 }
             }
         }
@@ -660,16 +661,16 @@ function getCompletionEntriesForDirectoryFragment(
     if (!tryDirectoryExists(host, baseDirectory)) return result;
 
     // Enumerate the available files if possible
-    const files = tryReadDirectory(host, baseDirectory, extensionOptions.extensions, /*exclude*/ undefined, /*include*/ ["./*"]);
+    const files = tryReadDirectory(host, baseDirectory, extensionOptions.extensionsToSearch, /*exclude*/ undefined, /*include*/ ["./*"]);
 
     if (files) {
         for (let filePath of files) {
             filePath = normalizePath(filePath);
-            if (exclude && comparePaths(filePath, exclude, scriptPath, ignoreCase) === Comparison.EqualTo) {
+            if (exclude && comparePaths(filePath, exclude, scriptDirectory, ignoreCase) === Comparison.EqualTo) {
                 continue;
             }
 
-            const { name, extension } = getFilenameWithExtensionOption(getBaseFileName(filePath), host.getCompilationSettings(), extensionOptions.includeExtensionsOption);
+            const { name, extension } = getFilenameWithExtensionOption(getBaseFileName(filePath), host.getCompilationSettings(), extensionOptions);
             result.add(nameAndKind(name, ScriptElementKind.scriptElement, extension));
         }
     }
@@ -689,17 +690,32 @@ function getCompletionEntriesForDirectoryFragment(
     return result;
 }
 
-function getFilenameWithExtensionOption(name: string, compilerOptions: CompilerOptions, includeExtensionsOption: IncludeExtensionsOption): { name: string, extension: Extension | undefined } {
-    const outputExtension = moduleSpecifiers.tryGetJSExtensionForFile(name, compilerOptions);
-    if (includeExtensionsOption === IncludeExtensionsOption.Exclude && !fileExtensionIsOneOf(name, [Extension.Json, Extension.Mts, Extension.Cts, Extension.Dmts, Extension.Dcts, Extension.Mjs, Extension.Cjs])) {
-        return { name: removeFileExtension(name), extension: tryGetExtensionFromPath(name) };
+function getFilenameWithExtensionOption(name: string, compilerOptions: CompilerOptions, extensionOptions: ExtensionOptions): { name: string, extension: Extension | undefined } {
+    if (extensionOptions.referenceKind === ReferenceKind.Filename) {
+        return { name, extension: tryGetExtensionFromPath(name) };
     }
-    else if ((fileExtensionIsOneOf(name, [Extension.Mts, Extension.Cts, Extension.Dmts, Extension.Dcts, Extension.Mjs, Extension.Cjs]) || includeExtensionsOption === IncludeExtensionsOption.ModuleSpecifierCompletion) && outputExtension) {
-        return { name: changeExtension(name, outputExtension), extension: outputExtension };
+
+    const endingPreference = getModuleSpecifierEndingPreference(extensionOptions.endingPreference, extensionOptions.resolutionMode, compilerOptions, extensionOptions.importingSourceFile);
+    if (endingPreference === ModuleSpecifierEnding.TsExtension) {
+        if (fileExtensionIsOneOf(name, supportedTSImplementationExtensions)) {
+            return { name, extension: tryGetExtensionFromPath(name) };
+        }
+        const outputExtension = moduleSpecifiers.tryGetJSExtensionForFile(name, compilerOptions);
+        return outputExtension
+            ? { name: changeExtension(name, outputExtension), extension: outputExtension }
+            : { name, extension: tryGetExtensionFromPath(name) };
     }
-    else {
-        return { name, extension: tryGetExtensionFromPath(name) };
+
+    if ((endingPreference === ModuleSpecifierEnding.Minimal || endingPreference === ModuleSpecifierEnding.Index) &&
+        fileExtensionIsOneOf(name, [Extension.Js, Extension.Jsx, Extension.Ts, Extension.Tsx, Extension.Dts])
+    ) {
+        return { name: removeFileExtension(name), extension: tryGetExtensionFromPath(name) };
     }
+
+    const outputExtension = moduleSpecifiers.tryGetJSExtensionForFile(name, compilerOptions);
+    return outputExtension
+        ? { name: changeExtension(name, outputExtension), extension: outputExtension }
+        : { name, extension: tryGetExtensionFromPath(name) };
 }
 
 /** @returns whether `fragment` was a match for any `paths` (which should indicate whether any other path completions should be offered) */
@@ -786,17 +802,17 @@ function getCompletionEntriesForNonRelativeModules(
     mode: ResolutionMode,
     compilerOptions: CompilerOptions,
     host: LanguageServiceHost,
-    includeExtensionsOption: IncludeExtensionsOption,
+    extensionOptions: ExtensionOptions,
     typeChecker: TypeChecker,
 ): readonly NameAndKind[] {
     const { baseUrl, paths } = compilerOptions;
 
     const result = createNameAndKindSet();
-    const extensionOptions = getExtensionOptions(compilerOptions, includeExtensionsOption);
+    const moduleResolution = getEmitModuleResolutionKind(compilerOptions);
     if (baseUrl) {
         const projectDir = compilerOptions.project || host.getCurrentDirectory();
         const absolute = normalizePath(combinePaths(projectDir, baseUrl));
-        getCompletionEntriesForDirectoryFragment(fragment, absolute, extensionOptions, host, /*exclude*/ undefined, result);
+        getCompletionEntriesForDirectoryFragment(fragment, absolute, extensionOptions, host, /*moduleSpecifierIsRelative*/ false, /*exclude*/ undefined, result);
         if (paths) {
             addCompletionEntriesFromPaths(result, fragment, absolute, extensionOptions, host, paths);
         }
@@ -809,7 +825,7 @@ function getCompletionEntriesForNonRelativeModules(
 
     getCompletionEntriesFromTypings(host, compilerOptions, scriptPath, fragmentDirectory, extensionOptions, result);
 
-    if (isEmitResolutionKindUsingNodeModules(compilerOptions)) {
+    if (moduleResolutionUsesNodeModules(moduleResolution)) {
         // If looking for a global package name, don't just include everything in `node_modules` because that includes dependencies' own dependencies.
         // (But do if we didn't find anything, e.g. 'package.json' missing.)
         let foundGlobal = false;
@@ -826,10 +842,10 @@ function getCompletionEntriesForNonRelativeModules(
             let ancestorLookup: (directory: string) => void | undefined = ancestor => {
                 const nodeModules = combinePaths(ancestor, "node_modules");
                 if (tryDirectoryExists(host, nodeModules)) {
-                    getCompletionEntriesForDirectoryFragment(fragment, nodeModules, extensionOptions, host, /*exclude*/ undefined, result);
+                    getCompletionEntriesForDirectoryFragment(fragment, nodeModules, extensionOptions, host, /*moduleSpecifierIsRelative*/ false, /*exclude*/ undefined, result);
                 }
             };
-            if (fragmentDirectory && isEmitModuleResolutionRespectingExportMaps(compilerOptions)) {
+            if (fragmentDirectory && getResolvePackageJsonExports(compilerOptions)) {
                 const nodeModulesDirectoryLookup = ancestorLookup;
                 ancestorLookup = ancestor => {
                     const components = getPathComponents(fragment);
@@ -967,13 +983,13 @@ function getModulesForPathsPattern(
     // done.
     const includeGlob = normalizedSuffix ? "**/*" + normalizedSuffix : "./*";
 
-    const matches = mapDefined(tryReadDirectory(host, baseDirectory, extensionOptions.extensions, /*exclude*/ undefined, [includeGlob]), match => {
+    const matches = mapDefined(tryReadDirectory(host, baseDirectory, extensionOptions.extensionsToSearch, /*exclude*/ undefined, [includeGlob]), match => {
         const trimmedWithPattern = trimPrefixAndSuffix(match);
         if (trimmedWithPattern) {
             if (containsSlash(trimmedWithPattern)) {
                 return directoryResult(getPathComponents(removeLeadingDirectorySeparator(trimmedWithPattern))[1]);
             }
-            const { name, extension } = getFilenameWithExtensionOption(trimmedWithPattern, host.getCompilationSettings(), extensionOptions.includeExtensionsOption);
+            const { name, extension } = getFilenameWithExtensionOption(trimmedWithPattern, host.getCompilationSettings(), extensionOptions);
             return nameAndKind(name, ScriptElementKind.scriptElement, extension);
         }
     });
@@ -1030,8 +1046,8 @@ function getTripleSlashReferenceCompletion(sourceFile: SourceFile, position: num
 
     const [, prefix, kind, toComplete] = match;
     const scriptPath = getDirectoryPath(sourceFile.path);
-    const names = kind === "path" ? getCompletionEntriesForDirectoryFragment(toComplete, scriptPath, getExtensionOptions(compilerOptions, IncludeExtensionsOption.Include), host, sourceFile.path)
-        : kind === "types" ? getCompletionEntriesFromTypings(host, compilerOptions, scriptPath, getFragmentDirectory(toComplete), getExtensionOptions(compilerOptions))
+    const names = kind === "path" ? getCompletionEntriesForDirectoryFragment(toComplete, scriptPath, getExtensionOptions(compilerOptions, ReferenceKind.Filename, sourceFile), host, /*moduleSpecifierIsRelative*/ true, sourceFile.path)
+        : kind === "types" ? getCompletionEntriesFromTypings(host, compilerOptions, scriptPath, getFragmentDirectory(toComplete), getExtensionOptions(compilerOptions, ReferenceKind.ModuleSpecifier, sourceFile))
         : Debug.fail();
     return addReplacementSpans(toComplete, range.pos + prefix.length, arrayFrom(names.values()));
 }
@@ -1071,7 +1087,7 @@ function getCompletionEntriesFromTypings(host: LanguageServiceHost, options: Com
                 const baseDirectory = combinePaths(directory, typeDirectoryName);
                 const remainingFragment = tryRemoveDirectoryPrefix(fragmentDirectory, packageName, hostGetCanonicalFileName(host));
                 if (remainingFragment !== undefined) {
-                    getCompletionEntriesForDirectoryFragment(remainingFragment, baseDirectory, extensionOptions, host, /*exclude*/ undefined, result);
+                    getCompletionEntriesForDirectoryFragment(remainingFragment, baseDirectory, extensionOptions, host, /*moduleSpecifierIsRelative*/ false, /*exclude*/ undefined, result);
                 }
             }
         }
diff --git a/src/services/utilities.ts b/src/services/utilities.ts
index ac93d22ba7699..8369ef43d80ba 100644
--- a/src/services/utilities.ts
+++ b/src/services/utilities.ts
@@ -2374,6 +2374,7 @@ export function programContainsModules(program: Program): boolean {
 export function programContainsEsModules(program: Program): boolean {
     return program.getSourceFiles().some(s => !s.isDeclarationFile && !program.isSourceFileFromExternalLibrary(s) && !!s.externalModuleIndicator);
 }
+// TODO: this function is, at best, poorly named. Use sites are pretty suspicious.
 /** @internal */
 export function compilerOptionsIndicateEsModules(compilerOptions: CompilerOptions): boolean {
     return !!compilerOptions.module || getEmitScriptTarget(compilerOptions) >= ScriptTarget.ES2015 || !!compilerOptions.noEmit;
@@ -2408,11 +2409,6 @@ export function getModuleSpecifierResolverHost(program: Program, host: LanguageS
     };
 }
 
-/** @internal */
-export function moduleResolutionRespectsExports(moduleResolution: ModuleResolutionKind): boolean {
-    return moduleResolution >= ModuleResolutionKind.Node16 && moduleResolution <= ModuleResolutionKind.NodeNext;
-}
-
 /** @internal */
 export function moduleResolutionUsesNodeModules(moduleResolution: ModuleResolutionKind): boolean {
     return moduleResolution === ModuleResolutionKind.NodeJs || moduleResolution >= ModuleResolutionKind.Node16 && moduleResolution <= ModuleResolutionKind.NodeNext;
diff --git a/src/testRunner/compilerRunner.ts b/src/testRunner/compilerRunner.ts
index bad01ecd0bb01..33d01f4c24953 100644
--- a/src/testRunner/compilerRunner.ts
+++ b/src/testRunner/compilerRunner.ts
@@ -135,8 +135,10 @@ class CompilerTest {
         "module",
         "moduleResolution",
         "moduleDetection",
+        "allowImportingTsExtensions",
         "target",
         "jsx",
+        "noEmit",
         "removeComments",
         "importHelpers",
         "importHelpers",
@@ -161,6 +163,8 @@ class CompilerTest {
         "useUnknownInCatchVariables",
         "noUncheckedIndexedAccess",
         "noPropertyAccessFromIndexSignature",
+        "resolvePackageJsonExports",
+        "resolvePackageJsonImports",
     ];
     private fileName: string;
     private justName: string;
diff --git a/src/testRunner/unittests/helpers.ts b/src/testRunner/unittests/helpers.ts
index 725fb7c4e60fb..4e5f2046a416a 100644
--- a/src/testRunner/unittests/helpers.ts
+++ b/src/testRunner/unittests/helpers.ts
@@ -170,4 +170,4 @@ export function updateProgram(oldProgram: ProgramWithSourceTexts, rootNames: rea
 export function updateProgramText(files: readonly NamedSourceText[], fileName: string, newProgramText: string) {
     const file = ts.find(files, f => f.name === fileName)!;
     file.text = file.text.updateProgram(newProgramText);
-}
\ No newline at end of file
+}
diff --git a/tests/baselines/reference/api/tsserverlibrary.d.ts b/tests/baselines/reference/api/tsserverlibrary.d.ts
index 0af2b39653975..cad75d3083540 100644
--- a/tests/baselines/reference/api/tsserverlibrary.d.ts
+++ b/tests/baselines/reference/api/tsserverlibrary.d.ts
@@ -6971,7 +6971,8 @@ declare namespace ts {
         Classic = 1,
         NodeJs = 2,
         Node16 = 3,
-        NodeNext = 99
+        NodeNext = 99,
+        Bundler = 100
     }
     enum ModuleDetectionKind {
         /**
@@ -7022,6 +7023,7 @@ declare namespace ts {
     }
     type CompilerOptionsValue = string | number | boolean | (string | number)[] | string[] | MapLike<string[]> | PluginImport[] | ProjectReference[] | null | undefined;
     interface CompilerOptions {
+        allowImportingTsExtensions?: boolean;
         allowJs?: boolean;
         allowSyntheticDefaultImports?: boolean;
         allowUmdGlobalAccess?: boolean;
@@ -7031,6 +7033,7 @@ declare namespace ts {
         baseUrl?: string;
         charset?: string;
         checkJs?: boolean;
+        customConditions?: string[];
         declaration?: boolean;
         declarationMap?: boolean;
         emitDeclarationOnly?: boolean;
@@ -7095,6 +7098,8 @@ declare namespace ts {
         incremental?: boolean;
         tsBuildInfoFile?: string;
         removeComments?: boolean;
+        resolvePackageJsonExports?: boolean;
+        resolvePackageJsonImports?: boolean;
         rootDir?: string;
         rootDirs?: string[];
         skipLibCheck?: boolean;
@@ -7266,6 +7271,11 @@ declare namespace ts {
         resolvedFileName: string;
         /** True if `resolvedFileName` comes from `node_modules`. */
         isExternalLibraryImport?: boolean;
+        /**
+         * True if the original module reference used a .ts extension to refer directly to a .ts file,
+         * which should produce an error during checking if emit is enabled.
+         */
+        resolvedUsingTsExtension?: boolean;
     }
     /**
      * ResolvedModule with an explicitly provided `extension` property.
@@ -8772,6 +8782,7 @@ declare namespace ts {
         parent: ConstructorDeclaration;
         name: Identifier;
     };
+    function emitModuleKindIsNonNodeESM(moduleKind: ModuleKind): boolean;
     function isJSDocOptionalParameter(node: ParameterDeclaration): boolean;
     function isOptionalDeclaration(declaration: Declaration): boolean;
     function createUnparsedSourceFile(text: string): UnparsedSource;
@@ -9202,8 +9213,11 @@ declare namespace ts {
     function createTypeReferenceDirectiveResolutionCache(currentDirectory: string, getCanonicalFileName: (s: string) => string, options?: CompilerOptions, packageJsonInfoCache?: PackageJsonInfoCache): TypeReferenceDirectiveResolutionCache;
     function resolveModuleNameFromCache(moduleName: string, containingFile: string, cache: ModuleResolutionCache, mode?: ResolutionMode): ResolvedModuleWithFailedLookupLocations | undefined;
     function resolveModuleName(moduleName: string, containingFile: string, compilerOptions: CompilerOptions, host: ModuleResolutionHost, cache?: ModuleResolutionCache, redirectedReference?: ResolvedProjectReference, resolutionMode?: ResolutionMode): ResolvedModuleWithFailedLookupLocations;
+    function bundlerModuleNameResolver(moduleName: string, containingFile: string, compilerOptions: CompilerOptions, host: ModuleResolutionHost, cache?: ModuleResolutionCache, redirectedReference?: ResolvedProjectReference): ResolvedModuleWithFailedLookupLocations;
     function nodeModuleNameResolver(moduleName: string, containingFile: string, compilerOptions: CompilerOptions, host: ModuleResolutionHost, cache?: ModuleResolutionCache, redirectedReference?: ResolvedProjectReference): ResolvedModuleWithFailedLookupLocations;
     function classicNameResolver(moduleName: string, containingFile: string, compilerOptions: CompilerOptions, host: ModuleResolutionHost, cache?: NonRelativeModuleNameResolutionCache, redirectedReference?: ResolvedProjectReference): ResolvedModuleWithFailedLookupLocations;
+    function moduleResolutionSupportsResolvingTsExtensions(compilerOptions: CompilerOptions): boolean;
+    function shouldAllowImportingTsExtension(compilerOptions: CompilerOptions, fromFileName?: string): boolean | "" | undefined;
     interface TypeReferenceDirectiveResolutionCache extends PerDirectoryResolutionCache<ResolvedTypeReferenceDirectiveWithFailedLookupLocations>, NonRelativeNameResolutionCache<ResolvedTypeReferenceDirectiveWithFailedLookupLocations>, PackageJsonInfoCache {
     }
     interface ModeAwareCache<T> {
diff --git a/tests/baselines/reference/api/typescript.d.ts b/tests/baselines/reference/api/typescript.d.ts
index eaf5c1e2626fa..c6bb421d196b8 100644
--- a/tests/baselines/reference/api/typescript.d.ts
+++ b/tests/baselines/reference/api/typescript.d.ts
@@ -3037,7 +3037,8 @@ declare namespace ts {
         Classic = 1,
         NodeJs = 2,
         Node16 = 3,
-        NodeNext = 99
+        NodeNext = 99,
+        Bundler = 100
     }
     enum ModuleDetectionKind {
         /**
@@ -3088,6 +3089,7 @@ declare namespace ts {
     }
     type CompilerOptionsValue = string | number | boolean | (string | number)[] | string[] | MapLike<string[]> | PluginImport[] | ProjectReference[] | null | undefined;
     interface CompilerOptions {
+        allowImportingTsExtensions?: boolean;
         allowJs?: boolean;
         allowSyntheticDefaultImports?: boolean;
         allowUmdGlobalAccess?: boolean;
@@ -3097,6 +3099,7 @@ declare namespace ts {
         baseUrl?: string;
         charset?: string;
         checkJs?: boolean;
+        customConditions?: string[];
         declaration?: boolean;
         declarationMap?: boolean;
         emitDeclarationOnly?: boolean;
@@ -3161,6 +3164,8 @@ declare namespace ts {
         incremental?: boolean;
         tsBuildInfoFile?: string;
         removeComments?: boolean;
+        resolvePackageJsonExports?: boolean;
+        resolvePackageJsonImports?: boolean;
         rootDir?: string;
         rootDirs?: string[];
         skipLibCheck?: boolean;
@@ -3332,6 +3337,11 @@ declare namespace ts {
         resolvedFileName: string;
         /** True if `resolvedFileName` comes from `node_modules`. */
         isExternalLibraryImport?: boolean;
+        /**
+         * True if the original module reference used a .ts extension to refer directly to a .ts file,
+         * which should produce an error during checking if emit is enabled.
+         */
+        resolvedUsingTsExtension?: boolean;
     }
     /**
      * ResolvedModule with an explicitly provided `extension` property.
@@ -4838,6 +4848,7 @@ declare namespace ts {
         parent: ConstructorDeclaration;
         name: Identifier;
     };
+    function emitModuleKindIsNonNodeESM(moduleKind: ModuleKind): boolean;
     function isJSDocOptionalParameter(node: ParameterDeclaration): boolean;
     function isOptionalDeclaration(declaration: Declaration): boolean;
     function createUnparsedSourceFile(text: string): UnparsedSource;
@@ -5268,8 +5279,11 @@ declare namespace ts {
     function createTypeReferenceDirectiveResolutionCache(currentDirectory: string, getCanonicalFileName: (s: string) => string, options?: CompilerOptions, packageJsonInfoCache?: PackageJsonInfoCache): TypeReferenceDirectiveResolutionCache;
     function resolveModuleNameFromCache(moduleName: string, containingFile: string, cache: ModuleResolutionCache, mode?: ResolutionMode): ResolvedModuleWithFailedLookupLocations | undefined;
     function resolveModuleName(moduleName: string, containingFile: string, compilerOptions: CompilerOptions, host: ModuleResolutionHost, cache?: ModuleResolutionCache, redirectedReference?: ResolvedProjectReference, resolutionMode?: ResolutionMode): ResolvedModuleWithFailedLookupLocations;
+    function bundlerModuleNameResolver(moduleName: string, containingFile: string, compilerOptions: CompilerOptions, host: ModuleResolutionHost, cache?: ModuleResolutionCache, redirectedReference?: ResolvedProjectReference): ResolvedModuleWithFailedLookupLocations;
     function nodeModuleNameResolver(moduleName: string, containingFile: string, compilerOptions: CompilerOptions, host: ModuleResolutionHost, cache?: ModuleResolutionCache, redirectedReference?: ResolvedProjectReference): ResolvedModuleWithFailedLookupLocations;
     function classicNameResolver(moduleName: string, containingFile: string, compilerOptions: CompilerOptions, host: ModuleResolutionHost, cache?: NonRelativeModuleNameResolutionCache, redirectedReference?: ResolvedProjectReference): ResolvedModuleWithFailedLookupLocations;
+    function moduleResolutionSupportsResolvingTsExtensions(compilerOptions: CompilerOptions): boolean;
+    function shouldAllowImportingTsExtension(compilerOptions: CompilerOptions, fromFileName?: string): boolean | "" | undefined;
     interface TypeReferenceDirectiveResolutionCache extends PerDirectoryResolutionCache<ResolvedTypeReferenceDirectiveWithFailedLookupLocations>, NonRelativeNameResolutionCache<ResolvedTypeReferenceDirectiveWithFailedLookupLocations>, PackageJsonInfoCache {
     }
     interface ModeAwareCache<T> {
diff --git a/tests/baselines/reference/autoImportAllowTsExtensions1.baseline.md b/tests/baselines/reference/autoImportAllowTsExtensions1.baseline.md
new file mode 100644
index 0000000000000..0e3c27ce7e96a
--- /dev/null
+++ b/tests/baselines/reference/autoImportAllowTsExtensions1.baseline.md
@@ -0,0 +1,36 @@
+```ts
+// @Filename: /main.ts
+/*|*/
+```
+
+## From completions
+
+- `Component` from `"./Component"`
+- `fromAtTypesFoo` from `"foo"`
+- `fromBar` from `"bar"`
+- `fromLocal` from `"./local"`
+
+```ts
+import { Component } from "./Component";
+
+Component
+```
+
+```ts
+import { fromAtTypesFoo } from "foo";
+
+fromAtTypesFoo
+```
+
+```ts
+import { fromBar } from "bar";
+
+fromBar
+```
+
+```ts
+import { fromLocal } from "./local";
+
+fromLocal
+```
+
diff --git a/tests/baselines/reference/autoImportAllowTsExtensions2.baseline.md b/tests/baselines/reference/autoImportAllowTsExtensions2.baseline.md
new file mode 100644
index 0000000000000..1117148b1877d
--- /dev/null
+++ b/tests/baselines/reference/autoImportAllowTsExtensions2.baseline.md
@@ -0,0 +1,36 @@
+```ts
+// @Filename: /main.ts
+/*|*/
+```
+
+## From completions
+
+- `Component` from `"./Component.tsx"`
+- `fromAtTypesFoo` from `"foo"`
+- `fromBar` from `"bar"`
+- `fromLocal` from `"./local.ts"`
+
+```ts
+import { Component } from "./Component.tsx";
+
+Component
+```
+
+```ts
+import { fromAtTypesFoo } from "foo";
+
+fromAtTypesFoo
+```
+
+```ts
+import { fromBar } from "bar";
+
+fromBar
+```
+
+```ts
+import { fromLocal } from "./local.ts";
+
+fromLocal
+```
+
diff --git a/tests/baselines/reference/autoImportAllowTsExtensions3.baseline.md b/tests/baselines/reference/autoImportAllowTsExtensions3.baseline.md
new file mode 100644
index 0000000000000..551ff404a6a33
--- /dev/null
+++ b/tests/baselines/reference/autoImportAllowTsExtensions3.baseline.md
@@ -0,0 +1,23 @@
+```ts
+// @Filename: /main.ts
+import { Component } from "./Component.tsx";
+/*|*/
+```
+
+## From completions
+
+- `fromDecl` from `"./decl"`
+- `fromLocal` from `"./local.ts"`
+
+```ts
+import { Component } from "./Component.tsx";
+import { fromDecl } from "./decl";
+fromDecl
+```
+
+```ts
+import { Component } from "./Component.tsx";
+import { fromLocal } from "./local.ts";
+fromLocal
+```
+
diff --git a/tests/baselines/reference/autoImportAllowTsExtensions4.baseline.md b/tests/baselines/reference/autoImportAllowTsExtensions4.baseline.md
new file mode 100644
index 0000000000000..cdae3c5eaa40b
--- /dev/null
+++ b/tests/baselines/reference/autoImportAllowTsExtensions4.baseline.md
@@ -0,0 +1,22 @@
+```ts
+// @Filename: /main.ts
+import { Component } from "./local.js";
+/*|*/
+```
+
+## From completions
+
+- `fromDecl` from `"./decl.js"`
+- `fromLocal` from `"./local.js"`
+
+```ts
+import { fromDecl } from "./decl.js";
+import { Component } from "./local.js";
+fromDecl
+```
+
+```ts
+import { Component, fromLocal } from "./local.js";
+fromLocal
+```
+
diff --git a/tests/baselines/reference/bundlerImportESM.js b/tests/baselines/reference/bundlerImportESM.js
new file mode 100644
index 0000000000000..efe3cbd491689
--- /dev/null
+++ b/tests/baselines/reference/bundlerImportESM.js
@@ -0,0 +1,26 @@
+//// [tests/cases/conformance/moduleResolution/bundler/bundlerImportESM.ts] ////
+
+//// [esm.mts]
+export const esm = 0;
+
+//// [not-actually-cjs.cts]
+import { esm } from "./esm.mjs";
+
+//// [package.json]
+{ "type": "commonjs" }
+
+//// [still-not-cjs.ts]
+import { esm } from "./esm.mjs";
+
+
+//// [esm.mjs]
+"use strict";
+Object.defineProperty(exports, "__esModule", { value: true });
+exports.esm = void 0;
+exports.esm = 0;
+//// [not-actually-cjs.cjs]
+"use strict";
+Object.defineProperty(exports, "__esModule", { value: true });
+//// [still-not-cjs.js]
+"use strict";
+Object.defineProperty(exports, "__esModule", { value: true });
diff --git a/tests/baselines/reference/bundlerImportESM.symbols b/tests/baselines/reference/bundlerImportESM.symbols
new file mode 100644
index 0000000000000..de03eed56fdc2
--- /dev/null
+++ b/tests/baselines/reference/bundlerImportESM.symbols
@@ -0,0 +1,12 @@
+=== /esm.mts ===
+export const esm = 0;
+>esm : Symbol(esm, Decl(esm.mts, 0, 12))
+
+=== /not-actually-cjs.cts ===
+import { esm } from "./esm.mjs";
+>esm : Symbol(esm, Decl(not-actually-cjs.cts, 0, 8))
+
+=== /still-not-cjs.ts ===
+import { esm } from "./esm.mjs";
+>esm : Symbol(esm, Decl(still-not-cjs.ts, 0, 8))
+
diff --git a/tests/baselines/reference/bundlerImportESM.types b/tests/baselines/reference/bundlerImportESM.types
new file mode 100644
index 0000000000000..3ffcb432c7bff
--- /dev/null
+++ b/tests/baselines/reference/bundlerImportESM.types
@@ -0,0 +1,13 @@
+=== /esm.mts ===
+export const esm = 0;
+>esm : 0
+>0 : 0
+
+=== /not-actually-cjs.cts ===
+import { esm } from "./esm.mjs";
+>esm : 0
+
+=== /still-not-cjs.ts ===
+import { esm } from "./esm.mjs";
+>esm : 0
+
diff --git a/tests/baselines/reference/bundlerImportTsExtensions(allowimportingtsextensions=false,noemit=false).errors.txt b/tests/baselines/reference/bundlerImportTsExtensions(allowimportingtsextensions=false,noemit=false).errors.txt
new file mode 100644
index 0000000000000..e679c61f21d2e
--- /dev/null
+++ b/tests/baselines/reference/bundlerImportTsExtensions(allowimportingtsextensions=false,noemit=false).errors.txt
@@ -0,0 +1,103 @@
+error TS5056: Cannot write file 'out/b.js' because it would be overwritten by multiple input files.
+error TS5056: Cannot write file 'out/c.js' because it would be overwritten by multiple input files.
+error TS6054: File '/project/e.txt' has an unsupported extension. The only supported extensions are '.ts', '.tsx', '.d.ts', '.js', '.jsx', '.cts', '.d.cts', '.cjs', '.mts', '.d.mts', '.mjs'.
+  The file is in the program because:
+    Root file specified for compilation
+/project/main.ts(3,16): error TS5097: An import path can only end with a '.ts' extension when 'allowImportingTsExtensions' is enabled.
+/project/main.ts(7,16): error TS5097: An import path can only end with a '.ts' extension when 'allowImportingTsExtensions' is enabled.
+/project/main.ts(8,16): error TS2846: A declaration file cannot be imported without 'import type'. Did you mean to import an implementation file './b' instead?
+/project/main.ts(11,16): error TS5097: An import path can only end with a '.ts' extension when 'allowImportingTsExtensions' is enabled.
+/project/main.ts(12,16): error TS5097: An import path can only end with a '.tsx' extension when 'allowImportingTsExtensions' is enabled.
+/project/main.ts(12,16): error TS6142: Module './c.tsx' was resolved to '/project/c.tsx', but '--jsx' is not set.
+/project/main.ts(16,16): error TS5097: An import path can only end with a '.ts' extension when 'allowImportingTsExtensions' is enabled.
+/project/types.d.ts(2,16): error TS2691: An import path cannot end with a '.d.ts' extension. Consider importing './a' instead.
+/project/types.d.ts(3,21): error TS2691: An import path cannot end with a '.d.ts' extension. Consider importing './a' instead.
+
+
+!!! error TS5056: Cannot write file 'out/b.js' because it would be overwritten by multiple input files.
+!!! error TS5056: Cannot write file 'out/c.js' because it would be overwritten by multiple input files.
+!!! error TS6054: File '/project/e.txt' has an unsupported extension. The only supported extensions are '.ts', '.tsx', '.d.ts', '.js', '.jsx', '.cts', '.d.cts', '.cjs', '.mts', '.d.mts', '.mjs'.
+!!! error TS6054:   The file is in the program because:
+!!! error TS6054:     Root file specified for compilation
+==== /project/a.ts (0 errors) ====
+    export {};
+    
+==== /project/b.ts (0 errors) ====
+    export {};
+    
+==== /project/b.js (0 errors) ====
+    export {};
+    
+==== /project/b.d.ts (0 errors) ====
+    export {};
+    
+==== /project/c.ts (0 errors) ====
+    export {};
+    
+==== /project/c.tsx (0 errors) ====
+    export {};
+    
+==== /project/d/index.ts (0 errors) ====
+    export {};
+    
+==== /project/e (0 errors) ====
+    WOMP WOMP BINARY DATA
+    
+==== /project/e.ts (0 errors) ====
+    export {};
+    
+==== /project/e.txt (0 errors) ====
+    The letter e is for elephant
+    This poem is not about elephants
+    It is about the letter e
+    - Authored by GitHub Copilot, Nov 2022
+    
+==== /project/e.txt.ts (0 errors) ====
+    export {};
+    
+==== /project/main.ts (7 errors) ====
+    import {} from "./a";
+    import {} from "./a.js";
+    import {} from "./a.ts";
+                   ~~~~~~~~
+!!! error TS5097: An import path can only end with a '.ts' extension when 'allowImportingTsExtensions' is enabled.
+    
+    import {} from "./b";
+    import {} from "./b.js";
+    import {} from "./b.ts";
+                   ~~~~~~~~
+!!! error TS5097: An import path can only end with a '.ts' extension when 'allowImportingTsExtensions' is enabled.
+    import {} from "./b.d.ts";
+                   ~~~~~~~~~~
+!!! error TS2846: A declaration file cannot be imported without 'import type'. Did you mean to import an implementation file './b' instead?
+    import type {} from "./b.d.ts";
+    
+    import {} from "./c.ts";
+                   ~~~~~~~~
+!!! error TS5097: An import path can only end with a '.ts' extension when 'allowImportingTsExtensions' is enabled.
+    import {} from "./c.tsx";
+                   ~~~~~~~~~
+!!! error TS5097: An import path can only end with a '.tsx' extension when 'allowImportingTsExtensions' is enabled.
+                   ~~~~~~~~~
+!!! error TS6142: Module './c.tsx' was resolved to '/project/c.tsx', but '--jsx' is not set.
+    
+    import {} from "./d";
+    import {} from "./d/index";
+    import {} from "./d/index.ts";
+                   ~~~~~~~~~~~~~~
+!!! error TS5097: An import path can only end with a '.ts' extension when 'allowImportingTsExtensions' is enabled.
+    
+    // These should not resolve, but preventing them has
+    // relatively little utility compared to the cost of
+    // the filesystem hits.
+    import {} from "./e";
+    import {} from "./e.txt";
+    
+==== /project/types.d.ts (2 errors) ====
+    import {} from "./a.ts";
+    import {} from "./a.d.ts";
+                   ~~~~~~~~~~
+!!! error TS2691: An import path cannot end with a '.d.ts' extension. Consider importing './a' instead.
+    import type {} from "./a.d.ts";
+                        ~~~~~~~~~~
+!!! error TS2691: An import path cannot end with a '.d.ts' extension. Consider importing './a' instead.
\ No newline at end of file
diff --git a/tests/baselines/reference/bundlerImportTsExtensions(allowimportingtsextensions=false,noemit=false).js b/tests/baselines/reference/bundlerImportTsExtensions(allowimportingtsextensions=false,noemit=false).js
new file mode 100644
index 0000000000000..e6f603d88dc3b
--- /dev/null
+++ b/tests/baselines/reference/bundlerImportTsExtensions(allowimportingtsextensions=false,noemit=false).js
@@ -0,0 +1,82 @@
+//// [tests/cases/conformance/moduleResolution/bundler/bundlerImportTsExtensions.ts] ////
+
+//// [a.ts]
+export {};
+
+//// [b.ts]
+export {};
+
+//// [b.js]
+export {};
+
+//// [b.d.ts]
+export {};
+
+//// [c.ts]
+export {};
+
+//// [c.tsx]
+export {};
+
+//// [index.ts]
+export {};
+
+//// [e]
+WOMP WOMP BINARY DATA
+
+//// [e.ts]
+export {};
+
+//// [e.txt]
+The letter e is for elephant
+This poem is not about elephants
+It is about the letter e
+- Authored by GitHub Copilot, Nov 2022
+
+//// [e.txt.ts]
+export {};
+
+//// [main.ts]
+import {} from "./a";
+import {} from "./a.js";
+import {} from "./a.ts";
+
+import {} from "./b";
+import {} from "./b.js";
+import {} from "./b.ts";
+import {} from "./b.d.ts";
+import type {} from "./b.d.ts";
+
+import {} from "./c.ts";
+import {} from "./c.tsx";
+
+import {} from "./d";
+import {} from "./d/index";
+import {} from "./d/index.ts";
+
+// These should not resolve, but preventing them has
+// relatively little utility compared to the cost of
+// the filesystem hits.
+import {} from "./e";
+import {} from "./e.txt";
+
+//// [types.d.ts]
+import {} from "./a.ts";
+import {} from "./a.d.ts";
+import type {} from "./a.d.ts";
+
+//// [a.js]
+"use strict";
+Object.defineProperty(exports, "__esModule", { value: true });
+//// [index.js]
+"use strict";
+Object.defineProperty(exports, "__esModule", { value: true });
+//// [e.js]
+"use strict";
+Object.defineProperty(exports, "__esModule", { value: true });
+//// [e.txt.js]
+"use strict";
+Object.defineProperty(exports, "__esModule", { value: true });
+//// [main.js]
+"use strict";
+Object.defineProperty(exports, "__esModule", { value: true });
diff --git a/tests/baselines/reference/bundlerImportTsExtensions(allowimportingtsextensions=false,noemit=false).symbols b/tests/baselines/reference/bundlerImportTsExtensions(allowimportingtsextensions=false,noemit=false).symbols
new file mode 100644
index 0000000000000..3c1dc17c50c28
--- /dev/null
+++ b/tests/baselines/reference/bundlerImportTsExtensions(allowimportingtsextensions=false,noemit=false).symbols
@@ -0,0 +1,66 @@
+=== /project/a.ts ===
+
+export {};
+
+=== /project/b.ts ===
+
+export {};
+
+=== /project/b.js ===
+
+export {};
+
+=== /project/b.d.ts ===
+
+export {};
+
+=== /project/c.ts ===
+
+export {};
+
+=== /project/c.tsx ===
+
+export {};
+
+=== /project/d/index.ts ===
+
+export {};
+
+=== /project/e.ts ===
+
+export {};
+
+=== /project/e.txt.ts ===
+
+export {};
+
+=== /project/main.ts ===
+
+import {} from "./a";
+import {} from "./a.js";
+import {} from "./a.ts";
+
+import {} from "./b";
+import {} from "./b.js";
+import {} from "./b.ts";
+import {} from "./b.d.ts";
+import type {} from "./b.d.ts";
+
+import {} from "./c.ts";
+import {} from "./c.tsx";
+
+import {} from "./d";
+import {} from "./d/index";
+import {} from "./d/index.ts";
+
+// These should not resolve, but preventing them has
+// relatively little utility compared to the cost of
+// the filesystem hits.
+import {} from "./e";
+import {} from "./e.txt";
+
+=== /project/types.d.ts ===
+
+import {} from "./a.ts";
+import {} from "./a.d.ts";
+import type {} from "./a.d.ts";
diff --git a/tests/baselines/reference/bundlerImportTsExtensions(allowimportingtsextensions=false,noemit=false).trace.json b/tests/baselines/reference/bundlerImportTsExtensions(allowimportingtsextensions=false,noemit=false).trace.json
new file mode 100644
index 0000000000000..16bd4a9de2e58
--- /dev/null
+++ b/tests/baselines/reference/bundlerImportTsExtensions(allowimportingtsextensions=false,noemit=false).trace.json
@@ -0,0 +1,101 @@
+[
+    "======== Resolving module './a' from '/project/main.ts'. ========",
+    "Explicitly specified module resolution kind: 'Bundler'.",
+    "Loading module as file / folder, candidate module location '/project/a', target file types: TypeScript, JavaScript, Declaration, JSON.",
+    "File '/project/a.ts' exist - use it as a name resolution result.",
+    "======== Module name './a' was successfully resolved to '/project/a.ts'. ========",
+    "======== Resolving module './a.js' from '/project/main.ts'. ========",
+    "Explicitly specified module resolution kind: 'Bundler'.",
+    "Loading module as file / folder, candidate module location '/project/a.js', target file types: TypeScript, JavaScript, Declaration, JSON.",
+    "File name '/project/a.js' has a '.js' extension - stripping it.",
+    "File '/project/a.ts' exist - use it as a name resolution result.",
+    "======== Module name './a.js' was successfully resolved to '/project/a.ts'. ========",
+    "======== Resolving module './a.ts' from '/project/main.ts'. ========",
+    "Explicitly specified module resolution kind: 'Bundler'.",
+    "Loading module as file / folder, candidate module location '/project/a.ts', target file types: TypeScript, JavaScript, Declaration, JSON.",
+    "File name '/project/a.ts' has a '.ts' extension - stripping it.",
+    "File '/project/a.ts' exist - use it as a name resolution result.",
+    "======== Module name './a.ts' was successfully resolved to '/project/a.ts'. ========",
+    "======== Resolving module './b' from '/project/main.ts'. ========",
+    "Explicitly specified module resolution kind: 'Bundler'.",
+    "Loading module as file / folder, candidate module location '/project/b', target file types: TypeScript, JavaScript, Declaration, JSON.",
+    "File '/project/b.ts' exist - use it as a name resolution result.",
+    "======== Module name './b' was successfully resolved to '/project/b.ts'. ========",
+    "======== Resolving module './b.js' from '/project/main.ts'. ========",
+    "Explicitly specified module resolution kind: 'Bundler'.",
+    "Loading module as file / folder, candidate module location '/project/b.js', target file types: TypeScript, JavaScript, Declaration, JSON.",
+    "File name '/project/b.js' has a '.js' extension - stripping it.",
+    "File '/project/b.ts' exist - use it as a name resolution result.",
+    "======== Module name './b.js' was successfully resolved to '/project/b.ts'. ========",
+    "======== Resolving module './b.ts' from '/project/main.ts'. ========",
+    "Explicitly specified module resolution kind: 'Bundler'.",
+    "Loading module as file / folder, candidate module location '/project/b.ts', target file types: TypeScript, JavaScript, Declaration, JSON.",
+    "File name '/project/b.ts' has a '.ts' extension - stripping it.",
+    "File '/project/b.ts' exist - use it as a name resolution result.",
+    "======== Module name './b.ts' was successfully resolved to '/project/b.ts'. ========",
+    "======== Resolving module './b.d.ts' from '/project/main.ts'. ========",
+    "Explicitly specified module resolution kind: 'Bundler'.",
+    "Loading module as file / folder, candidate module location '/project/b.d.ts', target file types: TypeScript, JavaScript, Declaration, JSON.",
+    "File name '/project/b.d.ts' has a '.d.ts' extension - stripping it.",
+    "File '/project/b.d.ts' exist - use it as a name resolution result.",
+    "======== Module name './b.d.ts' was successfully resolved to '/project/b.d.ts'. ========",
+    "======== Resolving module './c.ts' from '/project/main.ts'. ========",
+    "Explicitly specified module resolution kind: 'Bundler'.",
+    "Loading module as file / folder, candidate module location '/project/c.ts', target file types: TypeScript, JavaScript, Declaration, JSON.",
+    "File name '/project/c.ts' has a '.ts' extension - stripping it.",
+    "File '/project/c.ts' exist - use it as a name resolution result.",
+    "======== Module name './c.ts' was successfully resolved to '/project/c.ts'. ========",
+    "======== Resolving module './c.tsx' from '/project/main.ts'. ========",
+    "Explicitly specified module resolution kind: 'Bundler'.",
+    "Loading module as file / folder, candidate module location '/project/c.tsx', target file types: TypeScript, JavaScript, Declaration, JSON.",
+    "File name '/project/c.tsx' has a '.tsx' extension - stripping it.",
+    "File '/project/c.tsx' exist - use it as a name resolution result.",
+    "======== Module name './c.tsx' was successfully resolved to '/project/c.tsx'. ========",
+    "======== Resolving module './d' from '/project/main.ts'. ========",
+    "Explicitly specified module resolution kind: 'Bundler'.",
+    "Loading module as file / folder, candidate module location '/project/d', target file types: TypeScript, JavaScript, Declaration, JSON.",
+    "File '/project/d.ts' does not exist.",
+    "File '/project/d.tsx' does not exist.",
+    "File '/project/d.d.ts' does not exist.",
+    "File '/project/d.js' does not exist.",
+    "File '/project/d.jsx' does not exist.",
+    "File '/project/d/package.json' does not exist.",
+    "File '/project/d/index.ts' exist - use it as a name resolution result.",
+    "======== Module name './d' was successfully resolved to '/project/d/index.ts'. ========",
+    "======== Resolving module './d/index' from '/project/main.ts'. ========",
+    "Explicitly specified module resolution kind: 'Bundler'.",
+    "Loading module as file / folder, candidate module location '/project/d/index', target file types: TypeScript, JavaScript, Declaration, JSON.",
+    "File '/project/d/index.ts' exist - use it as a name resolution result.",
+    "======== Module name './d/index' was successfully resolved to '/project/d/index.ts'. ========",
+    "======== Resolving module './d/index.ts' from '/project/main.ts'. ========",
+    "Explicitly specified module resolution kind: 'Bundler'.",
+    "Loading module as file / folder, candidate module location '/project/d/index.ts', target file types: TypeScript, JavaScript, Declaration, JSON.",
+    "File name '/project/d/index.ts' has a '.ts' extension - stripping it.",
+    "File '/project/d/index.ts' exist - use it as a name resolution result.",
+    "======== Module name './d/index.ts' was successfully resolved to '/project/d/index.ts'. ========",
+    "======== Resolving module './e' from '/project/main.ts'. ========",
+    "Explicitly specified module resolution kind: 'Bundler'.",
+    "Loading module as file / folder, candidate module location '/project/e', target file types: TypeScript, JavaScript, Declaration, JSON.",
+    "File '/project/e.ts' exist - use it as a name resolution result.",
+    "======== Module name './e' was successfully resolved to '/project/e.ts'. ========",
+    "======== Resolving module './e.txt' from '/project/main.ts'. ========",
+    "Explicitly specified module resolution kind: 'Bundler'.",
+    "Loading module as file / folder, candidate module location '/project/e.txt', target file types: TypeScript, JavaScript, Declaration, JSON.",
+    "File '/project/e.txt.ts' exist - use it as a name resolution result.",
+    "======== Module name './e.txt' was successfully resolved to '/project/e.txt.ts'. ========",
+    "======== Resolving module './a.ts' from '/project/types.d.ts'. ========",
+    "Resolution for module './a.ts' was found in cache from location '/project'.",
+    "======== Module name './a.ts' was successfully resolved to '/project/a.ts'. ========",
+    "======== Resolving module './a.d.ts' from '/project/types.d.ts'. ========",
+    "Explicitly specified module resolution kind: 'Bundler'.",
+    "Loading module as file / folder, candidate module location '/project/a.d.ts', target file types: TypeScript, JavaScript, Declaration, JSON.",
+    "File name '/project/a.d.ts' has a '.d.ts' extension - stripping it.",
+    "File '/project/a.d.ts' does not exist.",
+    "File '/project/a.d.ts.ts' does not exist.",
+    "File '/project/a.d.ts.tsx' does not exist.",
+    "File '/project/a.d.ts.d.ts' does not exist.",
+    "File '/project/a.d.ts.js' does not exist.",
+    "File '/project/a.d.ts.jsx' does not exist.",
+    "Directory '/project/a.d.ts' does not exist, skipping all lookups in it.",
+    "======== Module name './a.d.ts' was not resolved. ========"
+]
\ No newline at end of file
diff --git a/tests/baselines/reference/bundlerImportTsExtensions(allowimportingtsextensions=false,noemit=false).types b/tests/baselines/reference/bundlerImportTsExtensions(allowimportingtsextensions=false,noemit=false).types
new file mode 100644
index 0000000000000..3c1dc17c50c28
--- /dev/null
+++ b/tests/baselines/reference/bundlerImportTsExtensions(allowimportingtsextensions=false,noemit=false).types
@@ -0,0 +1,66 @@
+=== /project/a.ts ===
+
+export {};
+
+=== /project/b.ts ===
+
+export {};
+
+=== /project/b.js ===
+
+export {};
+
+=== /project/b.d.ts ===
+
+export {};
+
+=== /project/c.ts ===
+
+export {};
+
+=== /project/c.tsx ===
+
+export {};
+
+=== /project/d/index.ts ===
+
+export {};
+
+=== /project/e.ts ===
+
+export {};
+
+=== /project/e.txt.ts ===
+
+export {};
+
+=== /project/main.ts ===
+
+import {} from "./a";
+import {} from "./a.js";
+import {} from "./a.ts";
+
+import {} from "./b";
+import {} from "./b.js";
+import {} from "./b.ts";
+import {} from "./b.d.ts";
+import type {} from "./b.d.ts";
+
+import {} from "./c.ts";
+import {} from "./c.tsx";
+
+import {} from "./d";
+import {} from "./d/index";
+import {} from "./d/index.ts";
+
+// These should not resolve, but preventing them has
+// relatively little utility compared to the cost of
+// the filesystem hits.
+import {} from "./e";
+import {} from "./e.txt";
+
+=== /project/types.d.ts ===
+
+import {} from "./a.ts";
+import {} from "./a.d.ts";
+import type {} from "./a.d.ts";
diff --git a/tests/baselines/reference/bundlerImportTsExtensions(allowimportingtsextensions=false,noemit=true).errors.txt b/tests/baselines/reference/bundlerImportTsExtensions(allowimportingtsextensions=false,noemit=true).errors.txt
new file mode 100644
index 0000000000000..a90647850052e
--- /dev/null
+++ b/tests/baselines/reference/bundlerImportTsExtensions(allowimportingtsextensions=false,noemit=true).errors.txt
@@ -0,0 +1,99 @@
+error TS6054: File '/project/e.txt' has an unsupported extension. The only supported extensions are '.ts', '.tsx', '.d.ts', '.js', '.jsx', '.cts', '.d.cts', '.cjs', '.mts', '.d.mts', '.mjs'.
+  The file is in the program because:
+    Root file specified for compilation
+/project/main.ts(3,16): error TS5097: An import path can only end with a '.ts' extension when 'allowImportingTsExtensions' is enabled.
+/project/main.ts(7,16): error TS5097: An import path can only end with a '.ts' extension when 'allowImportingTsExtensions' is enabled.
+/project/main.ts(8,16): error TS2846: A declaration file cannot be imported without 'import type'. Did you mean to import an implementation file './b' instead?
+/project/main.ts(11,16): error TS5097: An import path can only end with a '.ts' extension when 'allowImportingTsExtensions' is enabled.
+/project/main.ts(12,16): error TS5097: An import path can only end with a '.tsx' extension when 'allowImportingTsExtensions' is enabled.
+/project/main.ts(12,16): error TS6142: Module './c.tsx' was resolved to '/project/c.tsx', but '--jsx' is not set.
+/project/main.ts(16,16): error TS5097: An import path can only end with a '.ts' extension when 'allowImportingTsExtensions' is enabled.
+/project/types.d.ts(2,16): error TS2691: An import path cannot end with a '.d.ts' extension. Consider importing './a' instead.
+/project/types.d.ts(3,21): error TS2691: An import path cannot end with a '.d.ts' extension. Consider importing './a' instead.
+
+
+!!! error TS6054: File '/project/e.txt' has an unsupported extension. The only supported extensions are '.ts', '.tsx', '.d.ts', '.js', '.jsx', '.cts', '.d.cts', '.cjs', '.mts', '.d.mts', '.mjs'.
+!!! error TS6054:   The file is in the program because:
+!!! error TS6054:     Root file specified for compilation
+==== /project/a.ts (0 errors) ====
+    export {};
+    
+==== /project/b.ts (0 errors) ====
+    export {};
+    
+==== /project/b.js (0 errors) ====
+    export {};
+    
+==== /project/b.d.ts (0 errors) ====
+    export {};
+    
+==== /project/c.ts (0 errors) ====
+    export {};
+    
+==== /project/c.tsx (0 errors) ====
+    export {};
+    
+==== /project/d/index.ts (0 errors) ====
+    export {};
+    
+==== /project/e (0 errors) ====
+    WOMP WOMP BINARY DATA
+    
+==== /project/e.ts (0 errors) ====
+    export {};
+    
+==== /project/e.txt (0 errors) ====
+    The letter e is for elephant
+    This poem is not about elephants
+    It is about the letter e
+    - Authored by GitHub Copilot, Nov 2022
+    
+==== /project/e.txt.ts (0 errors) ====
+    export {};
+    
+==== /project/main.ts (7 errors) ====
+    import {} from "./a";
+    import {} from "./a.js";
+    import {} from "./a.ts";
+                   ~~~~~~~~
+!!! error TS5097: An import path can only end with a '.ts' extension when 'allowImportingTsExtensions' is enabled.
+    
+    import {} from "./b";
+    import {} from "./b.js";
+    import {} from "./b.ts";
+                   ~~~~~~~~
+!!! error TS5097: An import path can only end with a '.ts' extension when 'allowImportingTsExtensions' is enabled.
+    import {} from "./b.d.ts";
+                   ~~~~~~~~~~
+!!! error TS2846: A declaration file cannot be imported without 'import type'. Did you mean to import an implementation file './b' instead?
+    import type {} from "./b.d.ts";
+    
+    import {} from "./c.ts";
+                   ~~~~~~~~
+!!! error TS5097: An import path can only end with a '.ts' extension when 'allowImportingTsExtensions' is enabled.
+    import {} from "./c.tsx";
+                   ~~~~~~~~~
+!!! error TS5097: An import path can only end with a '.tsx' extension when 'allowImportingTsExtensions' is enabled.
+                   ~~~~~~~~~
+!!! error TS6142: Module './c.tsx' was resolved to '/project/c.tsx', but '--jsx' is not set.
+    
+    import {} from "./d";
+    import {} from "./d/index";
+    import {} from "./d/index.ts";
+                   ~~~~~~~~~~~~~~
+!!! error TS5097: An import path can only end with a '.ts' extension when 'allowImportingTsExtensions' is enabled.
+    
+    // These should not resolve, but preventing them has
+    // relatively little utility compared to the cost of
+    // the filesystem hits.
+    import {} from "./e";
+    import {} from "./e.txt";
+    
+==== /project/types.d.ts (2 errors) ====
+    import {} from "./a.ts";
+    import {} from "./a.d.ts";
+                   ~~~~~~~~~~
+!!! error TS2691: An import path cannot end with a '.d.ts' extension. Consider importing './a' instead.
+    import type {} from "./a.d.ts";
+                        ~~~~~~~~~~
+!!! error TS2691: An import path cannot end with a '.d.ts' extension. Consider importing './a' instead.
\ No newline at end of file
diff --git a/tests/baselines/reference/bundlerImportTsExtensions(allowimportingtsextensions=false,noemit=true).symbols b/tests/baselines/reference/bundlerImportTsExtensions(allowimportingtsextensions=false,noemit=true).symbols
new file mode 100644
index 0000000000000..3c1dc17c50c28
--- /dev/null
+++ b/tests/baselines/reference/bundlerImportTsExtensions(allowimportingtsextensions=false,noemit=true).symbols
@@ -0,0 +1,66 @@
+=== /project/a.ts ===
+
+export {};
+
+=== /project/b.ts ===
+
+export {};
+
+=== /project/b.js ===
+
+export {};
+
+=== /project/b.d.ts ===
+
+export {};
+
+=== /project/c.ts ===
+
+export {};
+
+=== /project/c.tsx ===
+
+export {};
+
+=== /project/d/index.ts ===
+
+export {};
+
+=== /project/e.ts ===
+
+export {};
+
+=== /project/e.txt.ts ===
+
+export {};
+
+=== /project/main.ts ===
+
+import {} from "./a";
+import {} from "./a.js";
+import {} from "./a.ts";
+
+import {} from "./b";
+import {} from "./b.js";
+import {} from "./b.ts";
+import {} from "./b.d.ts";
+import type {} from "./b.d.ts";
+
+import {} from "./c.ts";
+import {} from "./c.tsx";
+
+import {} from "./d";
+import {} from "./d/index";
+import {} from "./d/index.ts";
+
+// These should not resolve, but preventing them has
+// relatively little utility compared to the cost of
+// the filesystem hits.
+import {} from "./e";
+import {} from "./e.txt";
+
+=== /project/types.d.ts ===
+
+import {} from "./a.ts";
+import {} from "./a.d.ts";
+import type {} from "./a.d.ts";
diff --git a/tests/baselines/reference/bundlerImportTsExtensions(allowimportingtsextensions=false,noemit=true).trace.json b/tests/baselines/reference/bundlerImportTsExtensions(allowimportingtsextensions=false,noemit=true).trace.json
new file mode 100644
index 0000000000000..16bd4a9de2e58
--- /dev/null
+++ b/tests/baselines/reference/bundlerImportTsExtensions(allowimportingtsextensions=false,noemit=true).trace.json
@@ -0,0 +1,101 @@
+[
+    "======== Resolving module './a' from '/project/main.ts'. ========",
+    "Explicitly specified module resolution kind: 'Bundler'.",
+    "Loading module as file / folder, candidate module location '/project/a', target file types: TypeScript, JavaScript, Declaration, JSON.",
+    "File '/project/a.ts' exist - use it as a name resolution result.",
+    "======== Module name './a' was successfully resolved to '/project/a.ts'. ========",
+    "======== Resolving module './a.js' from '/project/main.ts'. ========",
+    "Explicitly specified module resolution kind: 'Bundler'.",
+    "Loading module as file / folder, candidate module location '/project/a.js', target file types: TypeScript, JavaScript, Declaration, JSON.",
+    "File name '/project/a.js' has a '.js' extension - stripping it.",
+    "File '/project/a.ts' exist - use it as a name resolution result.",
+    "======== Module name './a.js' was successfully resolved to '/project/a.ts'. ========",
+    "======== Resolving module './a.ts' from '/project/main.ts'. ========",
+    "Explicitly specified module resolution kind: 'Bundler'.",
+    "Loading module as file / folder, candidate module location '/project/a.ts', target file types: TypeScript, JavaScript, Declaration, JSON.",
+    "File name '/project/a.ts' has a '.ts' extension - stripping it.",
+    "File '/project/a.ts' exist - use it as a name resolution result.",
+    "======== Module name './a.ts' was successfully resolved to '/project/a.ts'. ========",
+    "======== Resolving module './b' from '/project/main.ts'. ========",
+    "Explicitly specified module resolution kind: 'Bundler'.",
+    "Loading module as file / folder, candidate module location '/project/b', target file types: TypeScript, JavaScript, Declaration, JSON.",
+    "File '/project/b.ts' exist - use it as a name resolution result.",
+    "======== Module name './b' was successfully resolved to '/project/b.ts'. ========",
+    "======== Resolving module './b.js' from '/project/main.ts'. ========",
+    "Explicitly specified module resolution kind: 'Bundler'.",
+    "Loading module as file / folder, candidate module location '/project/b.js', target file types: TypeScript, JavaScript, Declaration, JSON.",
+    "File name '/project/b.js' has a '.js' extension - stripping it.",
+    "File '/project/b.ts' exist - use it as a name resolution result.",
+    "======== Module name './b.js' was successfully resolved to '/project/b.ts'. ========",
+    "======== Resolving module './b.ts' from '/project/main.ts'. ========",
+    "Explicitly specified module resolution kind: 'Bundler'.",
+    "Loading module as file / folder, candidate module location '/project/b.ts', target file types: TypeScript, JavaScript, Declaration, JSON.",
+    "File name '/project/b.ts' has a '.ts' extension - stripping it.",
+    "File '/project/b.ts' exist - use it as a name resolution result.",
+    "======== Module name './b.ts' was successfully resolved to '/project/b.ts'. ========",
+    "======== Resolving module './b.d.ts' from '/project/main.ts'. ========",
+    "Explicitly specified module resolution kind: 'Bundler'.",
+    "Loading module as file / folder, candidate module location '/project/b.d.ts', target file types: TypeScript, JavaScript, Declaration, JSON.",
+    "File name '/project/b.d.ts' has a '.d.ts' extension - stripping it.",
+    "File '/project/b.d.ts' exist - use it as a name resolution result.",
+    "======== Module name './b.d.ts' was successfully resolved to '/project/b.d.ts'. ========",
+    "======== Resolving module './c.ts' from '/project/main.ts'. ========",
+    "Explicitly specified module resolution kind: 'Bundler'.",
+    "Loading module as file / folder, candidate module location '/project/c.ts', target file types: TypeScript, JavaScript, Declaration, JSON.",
+    "File name '/project/c.ts' has a '.ts' extension - stripping it.",
+    "File '/project/c.ts' exist - use it as a name resolution result.",
+    "======== Module name './c.ts' was successfully resolved to '/project/c.ts'. ========",
+    "======== Resolving module './c.tsx' from '/project/main.ts'. ========",
+    "Explicitly specified module resolution kind: 'Bundler'.",
+    "Loading module as file / folder, candidate module location '/project/c.tsx', target file types: TypeScript, JavaScript, Declaration, JSON.",
+    "File name '/project/c.tsx' has a '.tsx' extension - stripping it.",
+    "File '/project/c.tsx' exist - use it as a name resolution result.",
+    "======== Module name './c.tsx' was successfully resolved to '/project/c.tsx'. ========",
+    "======== Resolving module './d' from '/project/main.ts'. ========",
+    "Explicitly specified module resolution kind: 'Bundler'.",
+    "Loading module as file / folder, candidate module location '/project/d', target file types: TypeScript, JavaScript, Declaration, JSON.",
+    "File '/project/d.ts' does not exist.",
+    "File '/project/d.tsx' does not exist.",
+    "File '/project/d.d.ts' does not exist.",
+    "File '/project/d.js' does not exist.",
+    "File '/project/d.jsx' does not exist.",
+    "File '/project/d/package.json' does not exist.",
+    "File '/project/d/index.ts' exist - use it as a name resolution result.",
+    "======== Module name './d' was successfully resolved to '/project/d/index.ts'. ========",
+    "======== Resolving module './d/index' from '/project/main.ts'. ========",
+    "Explicitly specified module resolution kind: 'Bundler'.",
+    "Loading module as file / folder, candidate module location '/project/d/index', target file types: TypeScript, JavaScript, Declaration, JSON.",
+    "File '/project/d/index.ts' exist - use it as a name resolution result.",
+    "======== Module name './d/index' was successfully resolved to '/project/d/index.ts'. ========",
+    "======== Resolving module './d/index.ts' from '/project/main.ts'. ========",
+    "Explicitly specified module resolution kind: 'Bundler'.",
+    "Loading module as file / folder, candidate module location '/project/d/index.ts', target file types: TypeScript, JavaScript, Declaration, JSON.",
+    "File name '/project/d/index.ts' has a '.ts' extension - stripping it.",
+    "File '/project/d/index.ts' exist - use it as a name resolution result.",
+    "======== Module name './d/index.ts' was successfully resolved to '/project/d/index.ts'. ========",
+    "======== Resolving module './e' from '/project/main.ts'. ========",
+    "Explicitly specified module resolution kind: 'Bundler'.",
+    "Loading module as file / folder, candidate module location '/project/e', target file types: TypeScript, JavaScript, Declaration, JSON.",
+    "File '/project/e.ts' exist - use it as a name resolution result.",
+    "======== Module name './e' was successfully resolved to '/project/e.ts'. ========",
+    "======== Resolving module './e.txt' from '/project/main.ts'. ========",
+    "Explicitly specified module resolution kind: 'Bundler'.",
+    "Loading module as file / folder, candidate module location '/project/e.txt', target file types: TypeScript, JavaScript, Declaration, JSON.",
+    "File '/project/e.txt.ts' exist - use it as a name resolution result.",
+    "======== Module name './e.txt' was successfully resolved to '/project/e.txt.ts'. ========",
+    "======== Resolving module './a.ts' from '/project/types.d.ts'. ========",
+    "Resolution for module './a.ts' was found in cache from location '/project'.",
+    "======== Module name './a.ts' was successfully resolved to '/project/a.ts'. ========",
+    "======== Resolving module './a.d.ts' from '/project/types.d.ts'. ========",
+    "Explicitly specified module resolution kind: 'Bundler'.",
+    "Loading module as file / folder, candidate module location '/project/a.d.ts', target file types: TypeScript, JavaScript, Declaration, JSON.",
+    "File name '/project/a.d.ts' has a '.d.ts' extension - stripping it.",
+    "File '/project/a.d.ts' does not exist.",
+    "File '/project/a.d.ts.ts' does not exist.",
+    "File '/project/a.d.ts.tsx' does not exist.",
+    "File '/project/a.d.ts.d.ts' does not exist.",
+    "File '/project/a.d.ts.js' does not exist.",
+    "File '/project/a.d.ts.jsx' does not exist.",
+    "Directory '/project/a.d.ts' does not exist, skipping all lookups in it.",
+    "======== Module name './a.d.ts' was not resolved. ========"
+]
\ No newline at end of file
diff --git a/tests/baselines/reference/bundlerImportTsExtensions(allowimportingtsextensions=false,noemit=true).types b/tests/baselines/reference/bundlerImportTsExtensions(allowimportingtsextensions=false,noemit=true).types
new file mode 100644
index 0000000000000..3c1dc17c50c28
--- /dev/null
+++ b/tests/baselines/reference/bundlerImportTsExtensions(allowimportingtsextensions=false,noemit=true).types
@@ -0,0 +1,66 @@
+=== /project/a.ts ===
+
+export {};
+
+=== /project/b.ts ===
+
+export {};
+
+=== /project/b.js ===
+
+export {};
+
+=== /project/b.d.ts ===
+
+export {};
+
+=== /project/c.ts ===
+
+export {};
+
+=== /project/c.tsx ===
+
+export {};
+
+=== /project/d/index.ts ===
+
+export {};
+
+=== /project/e.ts ===
+
+export {};
+
+=== /project/e.txt.ts ===
+
+export {};
+
+=== /project/main.ts ===
+
+import {} from "./a";
+import {} from "./a.js";
+import {} from "./a.ts";
+
+import {} from "./b";
+import {} from "./b.js";
+import {} from "./b.ts";
+import {} from "./b.d.ts";
+import type {} from "./b.d.ts";
+
+import {} from "./c.ts";
+import {} from "./c.tsx";
+
+import {} from "./d";
+import {} from "./d/index";
+import {} from "./d/index.ts";
+
+// These should not resolve, but preventing them has
+// relatively little utility compared to the cost of
+// the filesystem hits.
+import {} from "./e";
+import {} from "./e.txt";
+
+=== /project/types.d.ts ===
+
+import {} from "./a.ts";
+import {} from "./a.d.ts";
+import type {} from "./a.d.ts";
diff --git a/tests/baselines/reference/bundlerImportTsExtensions(allowimportingtsextensions=true,noemit=false).errors.txt b/tests/baselines/reference/bundlerImportTsExtensions(allowimportingtsextensions=true,noemit=false).errors.txt
new file mode 100644
index 0000000000000..683dac372525f
--- /dev/null
+++ b/tests/baselines/reference/bundlerImportTsExtensions(allowimportingtsextensions=true,noemit=false).errors.txt
@@ -0,0 +1,90 @@
+error TS5056: Cannot write file 'out/b.js' because it would be overwritten by multiple input files.
+error TS5056: Cannot write file 'out/c.js' because it would be overwritten by multiple input files.
+error TS5096: Option 'allowImportingTsExtensions' can only be used when 'moduleResolution' is set to 'bundler' and either 'noEmit' or 'emitDeclarationOnly' is set.
+error TS6054: File '/project/e.txt' has an unsupported extension. The only supported extensions are '.ts', '.tsx', '.d.ts', '.js', '.jsx', '.cts', '.d.cts', '.cjs', '.mts', '.d.mts', '.mjs'.
+  The file is in the program because:
+    Root file specified for compilation
+/project/main.ts(8,16): error TS2846: A declaration file cannot be imported without 'import type'. Did you mean to import an implementation file './b' instead?
+/project/main.ts(12,16): error TS6142: Module './c.tsx' was resolved to '/project/c.tsx', but '--jsx' is not set.
+/project/types.d.ts(2,16): error TS2691: An import path cannot end with a '.d.ts' extension. Consider importing './a' instead.
+/project/types.d.ts(3,21): error TS2691: An import path cannot end with a '.d.ts' extension. Consider importing './a' instead.
+
+
+!!! error TS5056: Cannot write file 'out/b.js' because it would be overwritten by multiple input files.
+!!! error TS5056: Cannot write file 'out/c.js' because it would be overwritten by multiple input files.
+!!! error TS5096: Option 'allowImportingTsExtensions' can only be used when 'moduleResolution' is set to 'bundler' and either 'noEmit' or 'emitDeclarationOnly' is set.
+!!! error TS6054: File '/project/e.txt' has an unsupported extension. The only supported extensions are '.ts', '.tsx', '.d.ts', '.js', '.jsx', '.cts', '.d.cts', '.cjs', '.mts', '.d.mts', '.mjs'.
+!!! error TS6054:   The file is in the program because:
+!!! error TS6054:     Root file specified for compilation
+==== /project/a.ts (0 errors) ====
+    export {};
+    
+==== /project/b.ts (0 errors) ====
+    export {};
+    
+==== /project/b.js (0 errors) ====
+    export {};
+    
+==== /project/b.d.ts (0 errors) ====
+    export {};
+    
+==== /project/c.ts (0 errors) ====
+    export {};
+    
+==== /project/c.tsx (0 errors) ====
+    export {};
+    
+==== /project/d/index.ts (0 errors) ====
+    export {};
+    
+==== /project/e (0 errors) ====
+    WOMP WOMP BINARY DATA
+    
+==== /project/e.ts (0 errors) ====
+    export {};
+    
+==== /project/e.txt (0 errors) ====
+    The letter e is for elephant
+    This poem is not about elephants
+    It is about the letter e
+    - Authored by GitHub Copilot, Nov 2022
+    
+==== /project/e.txt.ts (0 errors) ====
+    export {};
+    
+==== /project/main.ts (2 errors) ====
+    import {} from "./a";
+    import {} from "./a.js";
+    import {} from "./a.ts";
+    
+    import {} from "./b";
+    import {} from "./b.js";
+    import {} from "./b.ts";
+    import {} from "./b.d.ts";
+                   ~~~~~~~~~~
+!!! error TS2846: A declaration file cannot be imported without 'import type'. Did you mean to import an implementation file './b' instead?
+    import type {} from "./b.d.ts";
+    
+    import {} from "./c.ts";
+    import {} from "./c.tsx";
+                   ~~~~~~~~~
+!!! error TS6142: Module './c.tsx' was resolved to '/project/c.tsx', but '--jsx' is not set.
+    
+    import {} from "./d";
+    import {} from "./d/index";
+    import {} from "./d/index.ts";
+    
+    // These should not resolve, but preventing them has
+    // relatively little utility compared to the cost of
+    // the filesystem hits.
+    import {} from "./e";
+    import {} from "./e.txt";
+    
+==== /project/types.d.ts (2 errors) ====
+    import {} from "./a.ts";
+    import {} from "./a.d.ts";
+                   ~~~~~~~~~~
+!!! error TS2691: An import path cannot end with a '.d.ts' extension. Consider importing './a' instead.
+    import type {} from "./a.d.ts";
+                        ~~~~~~~~~~
+!!! error TS2691: An import path cannot end with a '.d.ts' extension. Consider importing './a' instead.
\ No newline at end of file
diff --git a/tests/baselines/reference/bundlerImportTsExtensions(allowimportingtsextensions=true,noemit=false).js b/tests/baselines/reference/bundlerImportTsExtensions(allowimportingtsextensions=true,noemit=false).js
new file mode 100644
index 0000000000000..e6f603d88dc3b
--- /dev/null
+++ b/tests/baselines/reference/bundlerImportTsExtensions(allowimportingtsextensions=true,noemit=false).js
@@ -0,0 +1,82 @@
+//// [tests/cases/conformance/moduleResolution/bundler/bundlerImportTsExtensions.ts] ////
+
+//// [a.ts]
+export {};
+
+//// [b.ts]
+export {};
+
+//// [b.js]
+export {};
+
+//// [b.d.ts]
+export {};
+
+//// [c.ts]
+export {};
+
+//// [c.tsx]
+export {};
+
+//// [index.ts]
+export {};
+
+//// [e]
+WOMP WOMP BINARY DATA
+
+//// [e.ts]
+export {};
+
+//// [e.txt]
+The letter e is for elephant
+This poem is not about elephants
+It is about the letter e
+- Authored by GitHub Copilot, Nov 2022
+
+//// [e.txt.ts]
+export {};
+
+//// [main.ts]
+import {} from "./a";
+import {} from "./a.js";
+import {} from "./a.ts";
+
+import {} from "./b";
+import {} from "./b.js";
+import {} from "./b.ts";
+import {} from "./b.d.ts";
+import type {} from "./b.d.ts";
+
+import {} from "./c.ts";
+import {} from "./c.tsx";
+
+import {} from "./d";
+import {} from "./d/index";
+import {} from "./d/index.ts";
+
+// These should not resolve, but preventing them has
+// relatively little utility compared to the cost of
+// the filesystem hits.
+import {} from "./e";
+import {} from "./e.txt";
+
+//// [types.d.ts]
+import {} from "./a.ts";
+import {} from "./a.d.ts";
+import type {} from "./a.d.ts";
+
+//// [a.js]
+"use strict";
+Object.defineProperty(exports, "__esModule", { value: true });
+//// [index.js]
+"use strict";
+Object.defineProperty(exports, "__esModule", { value: true });
+//// [e.js]
+"use strict";
+Object.defineProperty(exports, "__esModule", { value: true });
+//// [e.txt.js]
+"use strict";
+Object.defineProperty(exports, "__esModule", { value: true });
+//// [main.js]
+"use strict";
+Object.defineProperty(exports, "__esModule", { value: true });
diff --git a/tests/baselines/reference/bundlerImportTsExtensions(allowimportingtsextensions=true,noemit=false).symbols b/tests/baselines/reference/bundlerImportTsExtensions(allowimportingtsextensions=true,noemit=false).symbols
new file mode 100644
index 0000000000000..3c1dc17c50c28
--- /dev/null
+++ b/tests/baselines/reference/bundlerImportTsExtensions(allowimportingtsextensions=true,noemit=false).symbols
@@ -0,0 +1,66 @@
+=== /project/a.ts ===
+
+export {};
+
+=== /project/b.ts ===
+
+export {};
+
+=== /project/b.js ===
+
+export {};
+
+=== /project/b.d.ts ===
+
+export {};
+
+=== /project/c.ts ===
+
+export {};
+
+=== /project/c.tsx ===
+
+export {};
+
+=== /project/d/index.ts ===
+
+export {};
+
+=== /project/e.ts ===
+
+export {};
+
+=== /project/e.txt.ts ===
+
+export {};
+
+=== /project/main.ts ===
+
+import {} from "./a";
+import {} from "./a.js";
+import {} from "./a.ts";
+
+import {} from "./b";
+import {} from "./b.js";
+import {} from "./b.ts";
+import {} from "./b.d.ts";
+import type {} from "./b.d.ts";
+
+import {} from "./c.ts";
+import {} from "./c.tsx";
+
+import {} from "./d";
+import {} from "./d/index";
+import {} from "./d/index.ts";
+
+// These should not resolve, but preventing them has
+// relatively little utility compared to the cost of
+// the filesystem hits.
+import {} from "./e";
+import {} from "./e.txt";
+
+=== /project/types.d.ts ===
+
+import {} from "./a.ts";
+import {} from "./a.d.ts";
+import type {} from "./a.d.ts";
diff --git a/tests/baselines/reference/bundlerImportTsExtensions(allowimportingtsextensions=true,noemit=false).trace.json b/tests/baselines/reference/bundlerImportTsExtensions(allowimportingtsextensions=true,noemit=false).trace.json
new file mode 100644
index 0000000000000..16bd4a9de2e58
--- /dev/null
+++ b/tests/baselines/reference/bundlerImportTsExtensions(allowimportingtsextensions=true,noemit=false).trace.json
@@ -0,0 +1,101 @@
+[
+    "======== Resolving module './a' from '/project/main.ts'. ========",
+    "Explicitly specified module resolution kind: 'Bundler'.",
+    "Loading module as file / folder, candidate module location '/project/a', target file types: TypeScript, JavaScript, Declaration, JSON.",
+    "File '/project/a.ts' exist - use it as a name resolution result.",
+    "======== Module name './a' was successfully resolved to '/project/a.ts'. ========",
+    "======== Resolving module './a.js' from '/project/main.ts'. ========",
+    "Explicitly specified module resolution kind: 'Bundler'.",
+    "Loading module as file / folder, candidate module location '/project/a.js', target file types: TypeScript, JavaScript, Declaration, JSON.",
+    "File name '/project/a.js' has a '.js' extension - stripping it.",
+    "File '/project/a.ts' exist - use it as a name resolution result.",
+    "======== Module name './a.js' was successfully resolved to '/project/a.ts'. ========",
+    "======== Resolving module './a.ts' from '/project/main.ts'. ========",
+    "Explicitly specified module resolution kind: 'Bundler'.",
+    "Loading module as file / folder, candidate module location '/project/a.ts', target file types: TypeScript, JavaScript, Declaration, JSON.",
+    "File name '/project/a.ts' has a '.ts' extension - stripping it.",
+    "File '/project/a.ts' exist - use it as a name resolution result.",
+    "======== Module name './a.ts' was successfully resolved to '/project/a.ts'. ========",
+    "======== Resolving module './b' from '/project/main.ts'. ========",
+    "Explicitly specified module resolution kind: 'Bundler'.",
+    "Loading module as file / folder, candidate module location '/project/b', target file types: TypeScript, JavaScript, Declaration, JSON.",
+    "File '/project/b.ts' exist - use it as a name resolution result.",
+    "======== Module name './b' was successfully resolved to '/project/b.ts'. ========",
+    "======== Resolving module './b.js' from '/project/main.ts'. ========",
+    "Explicitly specified module resolution kind: 'Bundler'.",
+    "Loading module as file / folder, candidate module location '/project/b.js', target file types: TypeScript, JavaScript, Declaration, JSON.",
+    "File name '/project/b.js' has a '.js' extension - stripping it.",
+    "File '/project/b.ts' exist - use it as a name resolution result.",
+    "======== Module name './b.js' was successfully resolved to '/project/b.ts'. ========",
+    "======== Resolving module './b.ts' from '/project/main.ts'. ========",
+    "Explicitly specified module resolution kind: 'Bundler'.",
+    "Loading module as file / folder, candidate module location '/project/b.ts', target file types: TypeScript, JavaScript, Declaration, JSON.",
+    "File name '/project/b.ts' has a '.ts' extension - stripping it.",
+    "File '/project/b.ts' exist - use it as a name resolution result.",
+    "======== Module name './b.ts' was successfully resolved to '/project/b.ts'. ========",
+    "======== Resolving module './b.d.ts' from '/project/main.ts'. ========",
+    "Explicitly specified module resolution kind: 'Bundler'.",
+    "Loading module as file / folder, candidate module location '/project/b.d.ts', target file types: TypeScript, JavaScript, Declaration, JSON.",
+    "File name '/project/b.d.ts' has a '.d.ts' extension - stripping it.",
+    "File '/project/b.d.ts' exist - use it as a name resolution result.",
+    "======== Module name './b.d.ts' was successfully resolved to '/project/b.d.ts'. ========",
+    "======== Resolving module './c.ts' from '/project/main.ts'. ========",
+    "Explicitly specified module resolution kind: 'Bundler'.",
+    "Loading module as file / folder, candidate module location '/project/c.ts', target file types: TypeScript, JavaScript, Declaration, JSON.",
+    "File name '/project/c.ts' has a '.ts' extension - stripping it.",
+    "File '/project/c.ts' exist - use it as a name resolution result.",
+    "======== Module name './c.ts' was successfully resolved to '/project/c.ts'. ========",
+    "======== Resolving module './c.tsx' from '/project/main.ts'. ========",
+    "Explicitly specified module resolution kind: 'Bundler'.",
+    "Loading module as file / folder, candidate module location '/project/c.tsx', target file types: TypeScript, JavaScript, Declaration, JSON.",
+    "File name '/project/c.tsx' has a '.tsx' extension - stripping it.",
+    "File '/project/c.tsx' exist - use it as a name resolution result.",
+    "======== Module name './c.tsx' was successfully resolved to '/project/c.tsx'. ========",
+    "======== Resolving module './d' from '/project/main.ts'. ========",
+    "Explicitly specified module resolution kind: 'Bundler'.",
+    "Loading module as file / folder, candidate module location '/project/d', target file types: TypeScript, JavaScript, Declaration, JSON.",
+    "File '/project/d.ts' does not exist.",
+    "File '/project/d.tsx' does not exist.",
+    "File '/project/d.d.ts' does not exist.",
+    "File '/project/d.js' does not exist.",
+    "File '/project/d.jsx' does not exist.",
+    "File '/project/d/package.json' does not exist.",
+    "File '/project/d/index.ts' exist - use it as a name resolution result.",
+    "======== Module name './d' was successfully resolved to '/project/d/index.ts'. ========",
+    "======== Resolving module './d/index' from '/project/main.ts'. ========",
+    "Explicitly specified module resolution kind: 'Bundler'.",
+    "Loading module as file / folder, candidate module location '/project/d/index', target file types: TypeScript, JavaScript, Declaration, JSON.",
+    "File '/project/d/index.ts' exist - use it as a name resolution result.",
+    "======== Module name './d/index' was successfully resolved to '/project/d/index.ts'. ========",
+    "======== Resolving module './d/index.ts' from '/project/main.ts'. ========",
+    "Explicitly specified module resolution kind: 'Bundler'.",
+    "Loading module as file / folder, candidate module location '/project/d/index.ts', target file types: TypeScript, JavaScript, Declaration, JSON.",
+    "File name '/project/d/index.ts' has a '.ts' extension - stripping it.",
+    "File '/project/d/index.ts' exist - use it as a name resolution result.",
+    "======== Module name './d/index.ts' was successfully resolved to '/project/d/index.ts'. ========",
+    "======== Resolving module './e' from '/project/main.ts'. ========",
+    "Explicitly specified module resolution kind: 'Bundler'.",
+    "Loading module as file / folder, candidate module location '/project/e', target file types: TypeScript, JavaScript, Declaration, JSON.",
+    "File '/project/e.ts' exist - use it as a name resolution result.",
+    "======== Module name './e' was successfully resolved to '/project/e.ts'. ========",
+    "======== Resolving module './e.txt' from '/project/main.ts'. ========",
+    "Explicitly specified module resolution kind: 'Bundler'.",
+    "Loading module as file / folder, candidate module location '/project/e.txt', target file types: TypeScript, JavaScript, Declaration, JSON.",
+    "File '/project/e.txt.ts' exist - use it as a name resolution result.",
+    "======== Module name './e.txt' was successfully resolved to '/project/e.txt.ts'. ========",
+    "======== Resolving module './a.ts' from '/project/types.d.ts'. ========",
+    "Resolution for module './a.ts' was found in cache from location '/project'.",
+    "======== Module name './a.ts' was successfully resolved to '/project/a.ts'. ========",
+    "======== Resolving module './a.d.ts' from '/project/types.d.ts'. ========",
+    "Explicitly specified module resolution kind: 'Bundler'.",
+    "Loading module as file / folder, candidate module location '/project/a.d.ts', target file types: TypeScript, JavaScript, Declaration, JSON.",
+    "File name '/project/a.d.ts' has a '.d.ts' extension - stripping it.",
+    "File '/project/a.d.ts' does not exist.",
+    "File '/project/a.d.ts.ts' does not exist.",
+    "File '/project/a.d.ts.tsx' does not exist.",
+    "File '/project/a.d.ts.d.ts' does not exist.",
+    "File '/project/a.d.ts.js' does not exist.",
+    "File '/project/a.d.ts.jsx' does not exist.",
+    "Directory '/project/a.d.ts' does not exist, skipping all lookups in it.",
+    "======== Module name './a.d.ts' was not resolved. ========"
+]
\ No newline at end of file
diff --git a/tests/baselines/reference/bundlerImportTsExtensions(allowimportingtsextensions=true,noemit=false).types b/tests/baselines/reference/bundlerImportTsExtensions(allowimportingtsextensions=true,noemit=false).types
new file mode 100644
index 0000000000000..3c1dc17c50c28
--- /dev/null
+++ b/tests/baselines/reference/bundlerImportTsExtensions(allowimportingtsextensions=true,noemit=false).types
@@ -0,0 +1,66 @@
+=== /project/a.ts ===
+
+export {};
+
+=== /project/b.ts ===
+
+export {};
+
+=== /project/b.js ===
+
+export {};
+
+=== /project/b.d.ts ===
+
+export {};
+
+=== /project/c.ts ===
+
+export {};
+
+=== /project/c.tsx ===
+
+export {};
+
+=== /project/d/index.ts ===
+
+export {};
+
+=== /project/e.ts ===
+
+export {};
+
+=== /project/e.txt.ts ===
+
+export {};
+
+=== /project/main.ts ===
+
+import {} from "./a";
+import {} from "./a.js";
+import {} from "./a.ts";
+
+import {} from "./b";
+import {} from "./b.js";
+import {} from "./b.ts";
+import {} from "./b.d.ts";
+import type {} from "./b.d.ts";
+
+import {} from "./c.ts";
+import {} from "./c.tsx";
+
+import {} from "./d";
+import {} from "./d/index";
+import {} from "./d/index.ts";
+
+// These should not resolve, but preventing them has
+// relatively little utility compared to the cost of
+// the filesystem hits.
+import {} from "./e";
+import {} from "./e.txt";
+
+=== /project/types.d.ts ===
+
+import {} from "./a.ts";
+import {} from "./a.d.ts";
+import type {} from "./a.d.ts";
diff --git a/tests/baselines/reference/bundlerImportTsExtensions(allowimportingtsextensions=true,noemit=true).errors.txt b/tests/baselines/reference/bundlerImportTsExtensions(allowimportingtsextensions=true,noemit=true).errors.txt
new file mode 100644
index 0000000000000..394208e16ad02
--- /dev/null
+++ b/tests/baselines/reference/bundlerImportTsExtensions(allowimportingtsextensions=true,noemit=true).errors.txt
@@ -0,0 +1,84 @@
+error TS6054: File '/project/e.txt' has an unsupported extension. The only supported extensions are '.ts', '.tsx', '.d.ts', '.js', '.jsx', '.cts', '.d.cts', '.cjs', '.mts', '.d.mts', '.mjs'.
+  The file is in the program because:
+    Root file specified for compilation
+/project/main.ts(8,16): error TS2846: A declaration file cannot be imported without 'import type'. Did you mean to import an implementation file './b' instead?
+/project/main.ts(12,16): error TS6142: Module './c.tsx' was resolved to '/project/c.tsx', but '--jsx' is not set.
+/project/types.d.ts(2,16): error TS2691: An import path cannot end with a '.d.ts' extension. Consider importing './a' instead.
+/project/types.d.ts(3,21): error TS2691: An import path cannot end with a '.d.ts' extension. Consider importing './a' instead.
+
+
+!!! error TS6054: File '/project/e.txt' has an unsupported extension. The only supported extensions are '.ts', '.tsx', '.d.ts', '.js', '.jsx', '.cts', '.d.cts', '.cjs', '.mts', '.d.mts', '.mjs'.
+!!! error TS6054:   The file is in the program because:
+!!! error TS6054:     Root file specified for compilation
+==== /project/a.ts (0 errors) ====
+    export {};
+    
+==== /project/b.ts (0 errors) ====
+    export {};
+    
+==== /project/b.js (0 errors) ====
+    export {};
+    
+==== /project/b.d.ts (0 errors) ====
+    export {};
+    
+==== /project/c.ts (0 errors) ====
+    export {};
+    
+==== /project/c.tsx (0 errors) ====
+    export {};
+    
+==== /project/d/index.ts (0 errors) ====
+    export {};
+    
+==== /project/e (0 errors) ====
+    WOMP WOMP BINARY DATA
+    
+==== /project/e.ts (0 errors) ====
+    export {};
+    
+==== /project/e.txt (0 errors) ====
+    The letter e is for elephant
+    This poem is not about elephants
+    It is about the letter e
+    - Authored by GitHub Copilot, Nov 2022
+    
+==== /project/e.txt.ts (0 errors) ====
+    export {};
+    
+==== /project/main.ts (2 errors) ====
+    import {} from "./a";
+    import {} from "./a.js";
+    import {} from "./a.ts";
+    
+    import {} from "./b";
+    import {} from "./b.js";
+    import {} from "./b.ts";
+    import {} from "./b.d.ts";
+                   ~~~~~~~~~~
+!!! error TS2846: A declaration file cannot be imported without 'import type'. Did you mean to import an implementation file './b' instead?
+    import type {} from "./b.d.ts";
+    
+    import {} from "./c.ts";
+    import {} from "./c.tsx";
+                   ~~~~~~~~~
+!!! error TS6142: Module './c.tsx' was resolved to '/project/c.tsx', but '--jsx' is not set.
+    
+    import {} from "./d";
+    import {} from "./d/index";
+    import {} from "./d/index.ts";
+    
+    // These should not resolve, but preventing them has
+    // relatively little utility compared to the cost of
+    // the filesystem hits.
+    import {} from "./e";
+    import {} from "./e.txt";
+    
+==== /project/types.d.ts (2 errors) ====
+    import {} from "./a.ts";
+    import {} from "./a.d.ts";
+                   ~~~~~~~~~~
+!!! error TS2691: An import path cannot end with a '.d.ts' extension. Consider importing './a' instead.
+    import type {} from "./a.d.ts";
+                        ~~~~~~~~~~
+!!! error TS2691: An import path cannot end with a '.d.ts' extension. Consider importing './a' instead.
\ No newline at end of file
diff --git a/tests/baselines/reference/bundlerImportTsExtensions(allowimportingtsextensions=true,noemit=true).symbols b/tests/baselines/reference/bundlerImportTsExtensions(allowimportingtsextensions=true,noemit=true).symbols
new file mode 100644
index 0000000000000..3c1dc17c50c28
--- /dev/null
+++ b/tests/baselines/reference/bundlerImportTsExtensions(allowimportingtsextensions=true,noemit=true).symbols
@@ -0,0 +1,66 @@
+=== /project/a.ts ===
+
+export {};
+
+=== /project/b.ts ===
+
+export {};
+
+=== /project/b.js ===
+
+export {};
+
+=== /project/b.d.ts ===
+
+export {};
+
+=== /project/c.ts ===
+
+export {};
+
+=== /project/c.tsx ===
+
+export {};
+
+=== /project/d/index.ts ===
+
+export {};
+
+=== /project/e.ts ===
+
+export {};
+
+=== /project/e.txt.ts ===
+
+export {};
+
+=== /project/main.ts ===
+
+import {} from "./a";
+import {} from "./a.js";
+import {} from "./a.ts";
+
+import {} from "./b";
+import {} from "./b.js";
+import {} from "./b.ts";
+import {} from "./b.d.ts";
+import type {} from "./b.d.ts";
+
+import {} from "./c.ts";
+import {} from "./c.tsx";
+
+import {} from "./d";
+import {} from "./d/index";
+import {} from "./d/index.ts";
+
+// These should not resolve, but preventing them has
+// relatively little utility compared to the cost of
+// the filesystem hits.
+import {} from "./e";
+import {} from "./e.txt";
+
+=== /project/types.d.ts ===
+
+import {} from "./a.ts";
+import {} from "./a.d.ts";
+import type {} from "./a.d.ts";
diff --git a/tests/baselines/reference/bundlerImportTsExtensions(allowimportingtsextensions=true,noemit=true).trace.json b/tests/baselines/reference/bundlerImportTsExtensions(allowimportingtsextensions=true,noemit=true).trace.json
new file mode 100644
index 0000000000000..16bd4a9de2e58
--- /dev/null
+++ b/tests/baselines/reference/bundlerImportTsExtensions(allowimportingtsextensions=true,noemit=true).trace.json
@@ -0,0 +1,101 @@
+[
+    "======== Resolving module './a' from '/project/main.ts'. ========",
+    "Explicitly specified module resolution kind: 'Bundler'.",
+    "Loading module as file / folder, candidate module location '/project/a', target file types: TypeScript, JavaScript, Declaration, JSON.",
+    "File '/project/a.ts' exist - use it as a name resolution result.",
+    "======== Module name './a' was successfully resolved to '/project/a.ts'. ========",
+    "======== Resolving module './a.js' from '/project/main.ts'. ========",
+    "Explicitly specified module resolution kind: 'Bundler'.",
+    "Loading module as file / folder, candidate module location '/project/a.js', target file types: TypeScript, JavaScript, Declaration, JSON.",
+    "File name '/project/a.js' has a '.js' extension - stripping it.",
+    "File '/project/a.ts' exist - use it as a name resolution result.",
+    "======== Module name './a.js' was successfully resolved to '/project/a.ts'. ========",
+    "======== Resolving module './a.ts' from '/project/main.ts'. ========",
+    "Explicitly specified module resolution kind: 'Bundler'.",
+    "Loading module as file / folder, candidate module location '/project/a.ts', target file types: TypeScript, JavaScript, Declaration, JSON.",
+    "File name '/project/a.ts' has a '.ts' extension - stripping it.",
+    "File '/project/a.ts' exist - use it as a name resolution result.",
+    "======== Module name './a.ts' was successfully resolved to '/project/a.ts'. ========",
+    "======== Resolving module './b' from '/project/main.ts'. ========",
+    "Explicitly specified module resolution kind: 'Bundler'.",
+    "Loading module as file / folder, candidate module location '/project/b', target file types: TypeScript, JavaScript, Declaration, JSON.",
+    "File '/project/b.ts' exist - use it as a name resolution result.",
+    "======== Module name './b' was successfully resolved to '/project/b.ts'. ========",
+    "======== Resolving module './b.js' from '/project/main.ts'. ========",
+    "Explicitly specified module resolution kind: 'Bundler'.",
+    "Loading module as file / folder, candidate module location '/project/b.js', target file types: TypeScript, JavaScript, Declaration, JSON.",
+    "File name '/project/b.js' has a '.js' extension - stripping it.",
+    "File '/project/b.ts' exist - use it as a name resolution result.",
+    "======== Module name './b.js' was successfully resolved to '/project/b.ts'. ========",
+    "======== Resolving module './b.ts' from '/project/main.ts'. ========",
+    "Explicitly specified module resolution kind: 'Bundler'.",
+    "Loading module as file / folder, candidate module location '/project/b.ts', target file types: TypeScript, JavaScript, Declaration, JSON.",
+    "File name '/project/b.ts' has a '.ts' extension - stripping it.",
+    "File '/project/b.ts' exist - use it as a name resolution result.",
+    "======== Module name './b.ts' was successfully resolved to '/project/b.ts'. ========",
+    "======== Resolving module './b.d.ts' from '/project/main.ts'. ========",
+    "Explicitly specified module resolution kind: 'Bundler'.",
+    "Loading module as file / folder, candidate module location '/project/b.d.ts', target file types: TypeScript, JavaScript, Declaration, JSON.",
+    "File name '/project/b.d.ts' has a '.d.ts' extension - stripping it.",
+    "File '/project/b.d.ts' exist - use it as a name resolution result.",
+    "======== Module name './b.d.ts' was successfully resolved to '/project/b.d.ts'. ========",
+    "======== Resolving module './c.ts' from '/project/main.ts'. ========",
+    "Explicitly specified module resolution kind: 'Bundler'.",
+    "Loading module as file / folder, candidate module location '/project/c.ts', target file types: TypeScript, JavaScript, Declaration, JSON.",
+    "File name '/project/c.ts' has a '.ts' extension - stripping it.",
+    "File '/project/c.ts' exist - use it as a name resolution result.",
+    "======== Module name './c.ts' was successfully resolved to '/project/c.ts'. ========",
+    "======== Resolving module './c.tsx' from '/project/main.ts'. ========",
+    "Explicitly specified module resolution kind: 'Bundler'.",
+    "Loading module as file / folder, candidate module location '/project/c.tsx', target file types: TypeScript, JavaScript, Declaration, JSON.",
+    "File name '/project/c.tsx' has a '.tsx' extension - stripping it.",
+    "File '/project/c.tsx' exist - use it as a name resolution result.",
+    "======== Module name './c.tsx' was successfully resolved to '/project/c.tsx'. ========",
+    "======== Resolving module './d' from '/project/main.ts'. ========",
+    "Explicitly specified module resolution kind: 'Bundler'.",
+    "Loading module as file / folder, candidate module location '/project/d', target file types: TypeScript, JavaScript, Declaration, JSON.",
+    "File '/project/d.ts' does not exist.",
+    "File '/project/d.tsx' does not exist.",
+    "File '/project/d.d.ts' does not exist.",
+    "File '/project/d.js' does not exist.",
+    "File '/project/d.jsx' does not exist.",
+    "File '/project/d/package.json' does not exist.",
+    "File '/project/d/index.ts' exist - use it as a name resolution result.",
+    "======== Module name './d' was successfully resolved to '/project/d/index.ts'. ========",
+    "======== Resolving module './d/index' from '/project/main.ts'. ========",
+    "Explicitly specified module resolution kind: 'Bundler'.",
+    "Loading module as file / folder, candidate module location '/project/d/index', target file types: TypeScript, JavaScript, Declaration, JSON.",
+    "File '/project/d/index.ts' exist - use it as a name resolution result.",
+    "======== Module name './d/index' was successfully resolved to '/project/d/index.ts'. ========",
+    "======== Resolving module './d/index.ts' from '/project/main.ts'. ========",
+    "Explicitly specified module resolution kind: 'Bundler'.",
+    "Loading module as file / folder, candidate module location '/project/d/index.ts', target file types: TypeScript, JavaScript, Declaration, JSON.",
+    "File name '/project/d/index.ts' has a '.ts' extension - stripping it.",
+    "File '/project/d/index.ts' exist - use it as a name resolution result.",
+    "======== Module name './d/index.ts' was successfully resolved to '/project/d/index.ts'. ========",
+    "======== Resolving module './e' from '/project/main.ts'. ========",
+    "Explicitly specified module resolution kind: 'Bundler'.",
+    "Loading module as file / folder, candidate module location '/project/e', target file types: TypeScript, JavaScript, Declaration, JSON.",
+    "File '/project/e.ts' exist - use it as a name resolution result.",
+    "======== Module name './e' was successfully resolved to '/project/e.ts'. ========",
+    "======== Resolving module './e.txt' from '/project/main.ts'. ========",
+    "Explicitly specified module resolution kind: 'Bundler'.",
+    "Loading module as file / folder, candidate module location '/project/e.txt', target file types: TypeScript, JavaScript, Declaration, JSON.",
+    "File '/project/e.txt.ts' exist - use it as a name resolution result.",
+    "======== Module name './e.txt' was successfully resolved to '/project/e.txt.ts'. ========",
+    "======== Resolving module './a.ts' from '/project/types.d.ts'. ========",
+    "Resolution for module './a.ts' was found in cache from location '/project'.",
+    "======== Module name './a.ts' was successfully resolved to '/project/a.ts'. ========",
+    "======== Resolving module './a.d.ts' from '/project/types.d.ts'. ========",
+    "Explicitly specified module resolution kind: 'Bundler'.",
+    "Loading module as file / folder, candidate module location '/project/a.d.ts', target file types: TypeScript, JavaScript, Declaration, JSON.",
+    "File name '/project/a.d.ts' has a '.d.ts' extension - stripping it.",
+    "File '/project/a.d.ts' does not exist.",
+    "File '/project/a.d.ts.ts' does not exist.",
+    "File '/project/a.d.ts.tsx' does not exist.",
+    "File '/project/a.d.ts.d.ts' does not exist.",
+    "File '/project/a.d.ts.js' does not exist.",
+    "File '/project/a.d.ts.jsx' does not exist.",
+    "Directory '/project/a.d.ts' does not exist, skipping all lookups in it.",
+    "======== Module name './a.d.ts' was not resolved. ========"
+]
\ No newline at end of file
diff --git a/tests/baselines/reference/bundlerImportTsExtensions(allowimportingtsextensions=true,noemit=true).types b/tests/baselines/reference/bundlerImportTsExtensions(allowimportingtsextensions=true,noemit=true).types
new file mode 100644
index 0000000000000..3c1dc17c50c28
--- /dev/null
+++ b/tests/baselines/reference/bundlerImportTsExtensions(allowimportingtsextensions=true,noemit=true).types
@@ -0,0 +1,66 @@
+=== /project/a.ts ===
+
+export {};
+
+=== /project/b.ts ===
+
+export {};
+
+=== /project/b.js ===
+
+export {};
+
+=== /project/b.d.ts ===
+
+export {};
+
+=== /project/c.ts ===
+
+export {};
+
+=== /project/c.tsx ===
+
+export {};
+
+=== /project/d/index.ts ===
+
+export {};
+
+=== /project/e.ts ===
+
+export {};
+
+=== /project/e.txt.ts ===
+
+export {};
+
+=== /project/main.ts ===
+
+import {} from "./a";
+import {} from "./a.js";
+import {} from "./a.ts";
+
+import {} from "./b";
+import {} from "./b.js";
+import {} from "./b.ts";
+import {} from "./b.d.ts";
+import type {} from "./b.d.ts";
+
+import {} from "./c.ts";
+import {} from "./c.tsx";
+
+import {} from "./d";
+import {} from "./d/index";
+import {} from "./d/index.ts";
+
+// These should not resolve, but preventing them has
+// relatively little utility compared to the cost of
+// the filesystem hits.
+import {} from "./e";
+import {} from "./e.txt";
+
+=== /project/types.d.ts ===
+
+import {} from "./a.ts";
+import {} from "./a.d.ts";
+import type {} from "./a.d.ts";
diff --git a/tests/baselines/reference/bundlerNodeModules1.errors.txt b/tests/baselines/reference/bundlerNodeModules1.errors.txt
new file mode 100644
index 0000000000000..69921a8ce1425
--- /dev/null
+++ b/tests/baselines/reference/bundlerNodeModules1.errors.txt
@@ -0,0 +1,59 @@
+error TS6504: File '/node_modules/dual/index.cjs' is a JavaScript file. Did you mean to enable the 'allowJs' option?
+  The file is in the program because:
+    Root file specified for compilation
+error TS6504: File '/node_modules/dual/index.js' is a JavaScript file. Did you mean to enable the 'allowJs' option?
+  The file is in the program because:
+    Root file specified for compilation
+/main.cts(1,15): error TS2305: Module '"dual"' has no exported member 'cjs'.
+/main.mts(1,15): error TS2305: Module '"dual"' has no exported member 'cjs'.
+/main.ts(1,15): error TS2305: Module '"dual"' has no exported member 'cjs'.
+
+
+!!! error TS6504: File '/node_modules/dual/index.cjs' is a JavaScript file. Did you mean to enable the 'allowJs' option?
+!!! error TS6504:   The file is in the program because:
+!!! error TS6504:     Root file specified for compilation
+!!! error TS6504: File '/node_modules/dual/index.js' is a JavaScript file. Did you mean to enable the 'allowJs' option?
+!!! error TS6504:   The file is in the program because:
+!!! error TS6504:     Root file specified for compilation
+==== /node_modules/dual/package.json (0 errors) ====
+    {
+      "name": "dual",
+      "version": "1.0.0",
+      "type": "module",
+      "main": "index.cjs",
+      "types": "index.d.cts",
+      "exports": {
+        ".": {
+          "import": "./index.js",
+          "require": "./index.cjs"
+        }
+      }
+    }
+    
+==== /node_modules/dual/index.js (0 errors) ====
+    export const esm = 0;
+    
+==== /node_modules/dual/index.d.ts (0 errors) ====
+    export const esm: number;
+    
+==== /node_modules/dual/index.cjs (0 errors) ====
+    exports.cjs = 0;
+    
+==== /node_modules/dual/index.d.cts (0 errors) ====
+    export const cjs: number;
+    
+==== /main.ts (1 errors) ====
+    import { esm, cjs } from "dual";
+                  ~~~
+!!! error TS2305: Module '"dual"' has no exported member 'cjs'.
+    
+==== /main.mts (1 errors) ====
+    import { esm, cjs } from "dual";
+                  ~~~
+!!! error TS2305: Module '"dual"' has no exported member 'cjs'.
+    
+==== /main.cts (1 errors) ====
+    import { esm, cjs } from "dual";
+                  ~~~
+!!! error TS2305: Module '"dual"' has no exported member 'cjs'.
+    
\ No newline at end of file
diff --git a/tests/baselines/reference/bundlerNodeModules1.js b/tests/baselines/reference/bundlerNodeModules1.js
new file mode 100644
index 0000000000000..8567c3f9b4561
--- /dev/null
+++ b/tests/baselines/reference/bundlerNodeModules1.js
@@ -0,0 +1,48 @@
+//// [tests/cases/conformance/moduleResolution/bundler/bundlerNodeModules1.ts] ////
+
+//// [package.json]
+{
+  "name": "dual",
+  "version": "1.0.0",
+  "type": "module",
+  "main": "index.cjs",
+  "types": "index.d.cts",
+  "exports": {
+    ".": {
+      "import": "./index.js",
+      "require": "./index.cjs"
+    }
+  }
+}
+
+//// [index.js]
+export const esm = 0;
+
+//// [index.d.ts]
+export const esm: number;
+
+//// [index.cjs]
+exports.cjs = 0;
+
+//// [index.d.cts]
+export const cjs: number;
+
+//// [main.ts]
+import { esm, cjs } from "dual";
+
+//// [main.mts]
+import { esm, cjs } from "dual";
+
+//// [main.cts]
+import { esm, cjs } from "dual";
+
+
+//// [main.js]
+"use strict";
+Object.defineProperty(exports, "__esModule", { value: true });
+//// [main.mjs]
+"use strict";
+Object.defineProperty(exports, "__esModule", { value: true });
+//// [main.cjs]
+"use strict";
+Object.defineProperty(exports, "__esModule", { value: true });
diff --git a/tests/baselines/reference/bundlerNodeModules1.symbols b/tests/baselines/reference/bundlerNodeModules1.symbols
new file mode 100644
index 0000000000000..d19c2e18f2c4d
--- /dev/null
+++ b/tests/baselines/reference/bundlerNodeModules1.symbols
@@ -0,0 +1,23 @@
+=== /node_modules/dual/index.d.ts ===
+export const esm: number;
+>esm : Symbol(esm, Decl(index.d.ts, 0, 12))
+
+=== /node_modules/dual/index.d.cts ===
+export const cjs: number;
+>cjs : Symbol(cjs, Decl(index.d.cts, 0, 12))
+
+=== /main.ts ===
+import { esm, cjs } from "dual";
+>esm : Symbol(esm, Decl(main.ts, 0, 8))
+>cjs : Symbol(cjs, Decl(main.ts, 0, 13))
+
+=== /main.mts ===
+import { esm, cjs } from "dual";
+>esm : Symbol(esm, Decl(main.mts, 0, 8))
+>cjs : Symbol(cjs, Decl(main.mts, 0, 13))
+
+=== /main.cts ===
+import { esm, cjs } from "dual";
+>esm : Symbol(esm, Decl(main.cts, 0, 8))
+>cjs : Symbol(cjs, Decl(main.cts, 0, 13))
+
diff --git a/tests/baselines/reference/bundlerNodeModules1.trace.json b/tests/baselines/reference/bundlerNodeModules1.trace.json
new file mode 100644
index 0000000000000..d1f74dccd4b1a
--- /dev/null
+++ b/tests/baselines/reference/bundlerNodeModules1.trace.json
@@ -0,0 +1,21 @@
+[
+    "======== Resolving module 'dual' from '/main.ts'. ========",
+    "Explicitly specified module resolution kind: 'Bundler'.",
+    "File '/package.json' does not exist.",
+    "Loading module 'dual' from 'node_modules' folder, target file types: TypeScript, JavaScript, Declaration, JSON.",
+    "Found 'package.json' at '/node_modules/dual/package.json'.",
+    "Matched 'exports' condition 'import'.",
+    "Using 'exports' subpath '.' with target './index.js'.",
+    "File name '/node_modules/dual/index.js' has a '.js' extension - stripping it.",
+    "File '/node_modules/dual/index.ts' does not exist.",
+    "File '/node_modules/dual/index.tsx' does not exist.",
+    "File '/node_modules/dual/index.d.ts' exist - use it as a name resolution result.",
+    "Resolving real path for '/node_modules/dual/index.d.ts', result '/node_modules/dual/index.d.ts'.",
+    "======== Module name 'dual' was successfully resolved to '/node_modules/dual/index.d.ts' with Package ID 'dual/index.d.ts@1.0.0'. ========",
+    "======== Resolving module 'dual' from '/main.mts'. ========",
+    "Resolution for module 'dual' was found in cache from location '/'.",
+    "======== Module name 'dual' was successfully resolved to '/node_modules/dual/index.d.ts' with Package ID 'dual/index.d.ts@1.0.0'. ========",
+    "======== Resolving module 'dual' from '/main.cts'. ========",
+    "Resolution for module 'dual' was found in cache from location '/'.",
+    "======== Module name 'dual' was successfully resolved to '/node_modules/dual/index.d.ts' with Package ID 'dual/index.d.ts@1.0.0'. ========"
+]
\ No newline at end of file
diff --git a/tests/baselines/reference/bundlerNodeModules1.types b/tests/baselines/reference/bundlerNodeModules1.types
new file mode 100644
index 0000000000000..038aac71d8928
--- /dev/null
+++ b/tests/baselines/reference/bundlerNodeModules1.types
@@ -0,0 +1,23 @@
+=== /node_modules/dual/index.d.ts ===
+export const esm: number;
+>esm : number
+
+=== /node_modules/dual/index.d.cts ===
+export const cjs: number;
+>cjs : number
+
+=== /main.ts ===
+import { esm, cjs } from "dual";
+>esm : number
+>cjs : any
+
+=== /main.mts ===
+import { esm, cjs } from "dual";
+>esm : number
+>cjs : any
+
+=== /main.cts ===
+import { esm, cjs } from "dual";
+>esm : number
+>cjs : any
+
diff --git a/tests/baselines/reference/bundlerRelative1.errors.txt b/tests/baselines/reference/bundlerRelative1.errors.txt
new file mode 100644
index 0000000000000..738eafa19304f
--- /dev/null
+++ b/tests/baselines/reference/bundlerRelative1.errors.txt
@@ -0,0 +1,39 @@
+/main.ts(4,16): error TS5097: An import path can only end with a '.ts' extension when 'allowImportingTsExtensions' is enabled.
+/main.ts(7,16): error TS2307: Cannot find module './redirect/index' or its corresponding type declarations.
+
+
+==== /dir/index.ts (0 errors) ====
+    export const x = 0;
+    
+==== /redirect/package.json (0 errors) ====
+    { "main": "../foo" }
+    
+==== /foo/index.ts (0 errors) ====
+    export const y = 0;
+    
+==== /types/esm.d.ts (0 errors) ====
+    declare const _: string;
+    export default _;
+    
+==== /types/cjs.d.ts (0 errors) ====
+    declare const _: string;
+    export = _;
+    
+==== /main.ts (2 errors) ====
+    import { x } from "./dir";
+    import {} from "./dir/index";
+    import {} from "./dir/index.js";
+    import {} from "./dir/index.ts";
+                   ~~~~~~~~~~~~~~~~
+!!! error TS5097: An import path can only end with a '.ts' extension when 'allowImportingTsExtensions' is enabled.
+    
+    import { y } from "./redirect";
+    import {} from "./redirect/index";
+                   ~~~~~~~~~~~~~~~~~~
+!!! error TS2307: Cannot find module './redirect/index' or its corresponding type declarations.
+    
+    import a from "./types/esm";
+    import * as esm from "./types/esm";
+    import b from "./types/cjs";
+    import * as cjs from "./types/cjs";
+    
\ No newline at end of file
diff --git a/tests/baselines/reference/bundlerRelative1.js b/tests/baselines/reference/bundlerRelative1.js
new file mode 100644
index 0000000000000..9238cc0f8ef3b
--- /dev/null
+++ b/tests/baselines/reference/bundlerRelative1.js
@@ -0,0 +1,47 @@
+//// [tests/cases/conformance/moduleResolution/bundler/bundlerRelative1.ts] ////
+
+//// [index.ts]
+export const x = 0;
+
+//// [package.json]
+{ "main": "../foo" }
+
+//// [index.ts]
+export const y = 0;
+
+//// [esm.d.ts]
+declare const _: string;
+export default _;
+
+//// [cjs.d.ts]
+declare const _: string;
+export = _;
+
+//// [main.ts]
+import { x } from "./dir";
+import {} from "./dir/index";
+import {} from "./dir/index.js";
+import {} from "./dir/index.ts";
+
+import { y } from "./redirect";
+import {} from "./redirect/index";
+
+import a from "./types/esm";
+import * as esm from "./types/esm";
+import b from "./types/cjs";
+import * as cjs from "./types/cjs";
+
+
+//// [index.js]
+"use strict";
+Object.defineProperty(exports, "__esModule", { value: true });
+exports.x = void 0;
+exports.x = 0;
+//// [index.js]
+"use strict";
+Object.defineProperty(exports, "__esModule", { value: true });
+exports.y = void 0;
+exports.y = 0;
+//// [main.js]
+"use strict";
+Object.defineProperty(exports, "__esModule", { value: true });
diff --git a/tests/baselines/reference/bundlerRelative1.symbols b/tests/baselines/reference/bundlerRelative1.symbols
new file mode 100644
index 0000000000000..4bbdf732a77c6
--- /dev/null
+++ b/tests/baselines/reference/bundlerRelative1.symbols
@@ -0,0 +1,47 @@
+=== /dir/index.ts ===
+export const x = 0;
+>x : Symbol(x, Decl(index.ts, 0, 12))
+
+=== /foo/index.ts ===
+export const y = 0;
+>y : Symbol(y, Decl(index.ts, 0, 12))
+
+=== /types/esm.d.ts ===
+declare const _: string;
+>_ : Symbol(_, Decl(esm.d.ts, 0, 13))
+
+export default _;
+>_ : Symbol(_, Decl(esm.d.ts, 0, 13))
+
+=== /types/cjs.d.ts ===
+declare const _: string;
+>_ : Symbol(_, Decl(cjs.d.ts, 0, 13))
+
+export = _;
+>_ : Symbol(_, Decl(cjs.d.ts, 0, 13))
+
+=== /main.ts ===
+import { x } from "./dir";
+>x : Symbol(x, Decl(main.ts, 0, 8))
+
+import {} from "./dir/index";
+import {} from "./dir/index.js";
+import {} from "./dir/index.ts";
+
+import { y } from "./redirect";
+>y : Symbol(y, Decl(main.ts, 5, 8))
+
+import {} from "./redirect/index";
+
+import a from "./types/esm";
+>a : Symbol(a, Decl(main.ts, 8, 6))
+
+import * as esm from "./types/esm";
+>esm : Symbol(esm, Decl(main.ts, 9, 6))
+
+import b from "./types/cjs";
+>b : Symbol(b, Decl(main.ts, 10, 6))
+
+import * as cjs from "./types/cjs";
+>cjs : Symbol(cjs, Decl(main.ts, 11, 6))
+
diff --git a/tests/baselines/reference/bundlerRelative1.trace.json b/tests/baselines/reference/bundlerRelative1.trace.json
new file mode 100644
index 0000000000000..19e7e28acd7ea
--- /dev/null
+++ b/tests/baselines/reference/bundlerRelative1.trace.json
@@ -0,0 +1,76 @@
+[
+    "======== Resolving module './dir' from '/main.ts'. ========",
+    "Explicitly specified module resolution kind: 'Bundler'.",
+    "Loading module as file / folder, candidate module location '/dir', target file types: TypeScript, JavaScript, Declaration, JSON.",
+    "File '/dir.ts' does not exist.",
+    "File '/dir.tsx' does not exist.",
+    "File '/dir.d.ts' does not exist.",
+    "File '/dir.js' does not exist.",
+    "File '/dir.jsx' does not exist.",
+    "File '/dir/package.json' does not exist.",
+    "File '/dir/index.ts' exist - use it as a name resolution result.",
+    "======== Module name './dir' was successfully resolved to '/dir/index.ts'. ========",
+    "======== Resolving module './dir/index' from '/main.ts'. ========",
+    "Explicitly specified module resolution kind: 'Bundler'.",
+    "Loading module as file / folder, candidate module location '/dir/index', target file types: TypeScript, JavaScript, Declaration, JSON.",
+    "File '/dir/index.ts' exist - use it as a name resolution result.",
+    "======== Module name './dir/index' was successfully resolved to '/dir/index.ts'. ========",
+    "======== Resolving module './dir/index.js' from '/main.ts'. ========",
+    "Explicitly specified module resolution kind: 'Bundler'.",
+    "Loading module as file / folder, candidate module location '/dir/index.js', target file types: TypeScript, JavaScript, Declaration, JSON.",
+    "File name '/dir/index.js' has a '.js' extension - stripping it.",
+    "File '/dir/index.ts' exist - use it as a name resolution result.",
+    "======== Module name './dir/index.js' was successfully resolved to '/dir/index.ts'. ========",
+    "======== Resolving module './dir/index.ts' from '/main.ts'. ========",
+    "Explicitly specified module resolution kind: 'Bundler'.",
+    "Loading module as file / folder, candidate module location '/dir/index.ts', target file types: TypeScript, JavaScript, Declaration, JSON.",
+    "File name '/dir/index.ts' has a '.ts' extension - stripping it.",
+    "File '/dir/index.ts' exist - use it as a name resolution result.",
+    "======== Module name './dir/index.ts' was successfully resolved to '/dir/index.ts'. ========",
+    "======== Resolving module './redirect' from '/main.ts'. ========",
+    "Explicitly specified module resolution kind: 'Bundler'.",
+    "Loading module as file / folder, candidate module location '/redirect', target file types: TypeScript, JavaScript, Declaration, JSON.",
+    "File '/redirect.ts' does not exist.",
+    "File '/redirect.tsx' does not exist.",
+    "File '/redirect.d.ts' does not exist.",
+    "File '/redirect.js' does not exist.",
+    "File '/redirect.jsx' does not exist.",
+    "Found 'package.json' at '/redirect/package.json'.",
+    "'package.json' does not have a 'typesVersions' field.",
+    "'package.json' does not have a 'typings' field.",
+    "'package.json' does not have a 'types' field.",
+    "'package.json' has 'main' field '../foo' that references '/foo'.",
+    "File '/foo' does not exist.",
+    "Loading module as file / folder, candidate module location '/foo', target file types: TypeScript, JavaScript, Declaration, JSON.",
+    "File '/foo.ts' does not exist.",
+    "File '/foo.tsx' does not exist.",
+    "File '/foo.d.ts' does not exist.",
+    "File '/foo.js' does not exist.",
+    "File '/foo.jsx' does not exist.",
+    "File '/foo/index.ts' exist - use it as a name resolution result.",
+    "======== Module name './redirect' was successfully resolved to '/foo/index.ts'. ========",
+    "======== Resolving module './redirect/index' from '/main.ts'. ========",
+    "Explicitly specified module resolution kind: 'Bundler'.",
+    "Loading module as file / folder, candidate module location '/redirect/index', target file types: TypeScript, JavaScript, Declaration, JSON.",
+    "File '/redirect/index.ts' does not exist.",
+    "File '/redirect/index.tsx' does not exist.",
+    "File '/redirect/index.d.ts' does not exist.",
+    "File '/redirect/index.js' does not exist.",
+    "File '/redirect/index.jsx' does not exist.",
+    "Directory '/redirect/index' does not exist, skipping all lookups in it.",
+    "======== Module name './redirect/index' was not resolved. ========",
+    "======== Resolving module './types/esm' from '/main.ts'. ========",
+    "Explicitly specified module resolution kind: 'Bundler'.",
+    "Loading module as file / folder, candidate module location '/types/esm', target file types: TypeScript, JavaScript, Declaration, JSON.",
+    "File '/types/esm.ts' does not exist.",
+    "File '/types/esm.tsx' does not exist.",
+    "File '/types/esm.d.ts' exist - use it as a name resolution result.",
+    "======== Module name './types/esm' was successfully resolved to '/types/esm.d.ts'. ========",
+    "======== Resolving module './types/cjs' from '/main.ts'. ========",
+    "Explicitly specified module resolution kind: 'Bundler'.",
+    "Loading module as file / folder, candidate module location '/types/cjs', target file types: TypeScript, JavaScript, Declaration, JSON.",
+    "File '/types/cjs.ts' does not exist.",
+    "File '/types/cjs.tsx' does not exist.",
+    "File '/types/cjs.d.ts' exist - use it as a name resolution result.",
+    "======== Module name './types/cjs' was successfully resolved to '/types/cjs.d.ts'. ========"
+]
\ No newline at end of file
diff --git a/tests/baselines/reference/bundlerRelative1.types b/tests/baselines/reference/bundlerRelative1.types
new file mode 100644
index 0000000000000..7e1e3e5e865c7
--- /dev/null
+++ b/tests/baselines/reference/bundlerRelative1.types
@@ -0,0 +1,49 @@
+=== /dir/index.ts ===
+export const x = 0;
+>x : 0
+>0 : 0
+
+=== /foo/index.ts ===
+export const y = 0;
+>y : 0
+>0 : 0
+
+=== /types/esm.d.ts ===
+declare const _: string;
+>_ : string
+
+export default _;
+>_ : string
+
+=== /types/cjs.d.ts ===
+declare const _: string;
+>_ : string
+
+export = _;
+>_ : string
+
+=== /main.ts ===
+import { x } from "./dir";
+>x : 0
+
+import {} from "./dir/index";
+import {} from "./dir/index.js";
+import {} from "./dir/index.ts";
+
+import { y } from "./redirect";
+>y : 0
+
+import {} from "./redirect/index";
+
+import a from "./types/esm";
+>a : string
+
+import * as esm from "./types/esm";
+>esm : typeof esm
+
+import b from "./types/cjs";
+>b : string
+
+import * as cjs from "./types/cjs";
+>cjs : string
+
diff --git a/tests/baselines/reference/bundlerSyntaxRestrictions.errors.txt b/tests/baselines/reference/bundlerSyntaxRestrictions.errors.txt
new file mode 100644
index 0000000000000..bae60c5cc726a
--- /dev/null
+++ b/tests/baselines/reference/bundlerSyntaxRestrictions.errors.txt
@@ -0,0 +1,31 @@
+error TS2468: Cannot find global value 'Promise'.
+/main.ts(2,1): error TS5099: Import assignment is not allowed when 'moduleResolution' is set to 'bundler'. Consider using 'import * as ns from "mod"', 'import {a} from "mod"', 'import d from "mod"', or another module format instead.
+/main.ts(3,1): error TS5100: Export assignment cannot be used when 'moduleResolution' is set to 'bundler'. Consider using 'export default' or another module format instead.
+/mainJs.js(2,1): error TS2712: A dynamic import call in ES5/ES3 requires the 'Promise' constructor.  Make sure you have a declaration for the 'Promise' constructor or include 'ES2015' in your '--lib' option.
+
+
+!!! error TS2468: Cannot find global value 'Promise'.
+==== /node_modules/@types/node/index.d.ts (0 errors) ====
+    declare var require: (...args: any[]) => any;
+    
+==== /mainJs.js (1 errors) ====
+    import {} from "./a";
+    import("./a");
+    ~~~~~~~~~~~~~
+!!! error TS2712: A dynamic import call in ES5/ES3 requires the 'Promise' constructor.  Make sure you have a declaration for the 'Promise' constructor or include 'ES2015' in your '--lib' option.
+    const _ = require("./a"); // No resolution
+    _.a; // any
+    
+==== /main.ts (2 errors) ====
+    import {} from "./a";
+    import _ = require("./a"); // Error
+    ~~~~~~~~~~~~~~~~~~~~~~~~~~
+!!! error TS5099: Import assignment is not allowed when 'moduleResolution' is set to 'bundler'. Consider using 'import * as ns from "mod"', 'import {a} from "mod"', 'import d from "mod"', or another module format instead.
+    export = {}; // Error
+    ~~~~~~~~~~~~
+!!! error TS5100: Export assignment cannot be used when 'moduleResolution' is set to 'bundler'. Consider using 'export default' or another module format instead.
+    export {};
+    
+==== /a.ts (0 errors) ====
+    export const a = "a";
+    
\ No newline at end of file
diff --git a/tests/baselines/reference/bundlerSyntaxRestrictions.js b/tests/baselines/reference/bundlerSyntaxRestrictions.js
new file mode 100644
index 0000000000000..cd49b3c2efd7d
--- /dev/null
+++ b/tests/baselines/reference/bundlerSyntaxRestrictions.js
@@ -0,0 +1,35 @@
+//// [tests/cases/conformance/moduleResolution/bundler/bundlerSyntaxRestrictions.ts] ////
+
+//// [index.d.ts]
+declare var require: (...args: any[]) => any;
+
+//// [mainJs.js]
+import {} from "./a";
+import("./a");
+const _ = require("./a"); // No resolution
+_.a; // any
+
+//// [main.ts]
+import {} from "./a";
+import _ = require("./a"); // Error
+export = {}; // Error
+export {};
+
+//// [a.ts]
+export const a = "a";
+
+
+//// [a.js]
+"use strict";
+Object.defineProperty(exports, "__esModule", { value: true });
+exports.a = void 0;
+exports.a = "a";
+//// [mainJs.js]
+"use strict";
+Object.defineProperty(exports, "__esModule", { value: true });
+Promise.resolve().then(function () { return require("./a"); });
+var _ = require("./a"); // No resolution
+_.a; // any
+//// [main.js]
+"use strict";
+module.exports = {};
diff --git a/tests/baselines/reference/bundlerSyntaxRestrictions.symbols b/tests/baselines/reference/bundlerSyntaxRestrictions.symbols
new file mode 100644
index 0000000000000..e48386d570bec
--- /dev/null
+++ b/tests/baselines/reference/bundlerSyntaxRestrictions.symbols
@@ -0,0 +1,29 @@
+=== /node_modules/@types/node/index.d.ts ===
+declare var require: (...args: any[]) => any;
+>require : Symbol(require, Decl(index.d.ts, 0, 11))
+>args : Symbol(args, Decl(index.d.ts, 0, 22))
+
+=== /mainJs.js ===
+import {} from "./a";
+import("./a");
+>"./a" : Symbol("/a", Decl(a.ts, 0, 0))
+
+const _ = require("./a"); // No resolution
+>_ : Symbol(_, Decl(mainJs.js, 2, 5))
+>require : Symbol(require, Decl(index.d.ts, 0, 11))
+
+_.a; // any
+>_ : Symbol(_, Decl(mainJs.js, 2, 5))
+
+=== /main.ts ===
+import {} from "./a";
+import _ = require("./a"); // Error
+>_ : Symbol(_, Decl(main.ts, 0, 21))
+
+export = {}; // Error
+export {};
+
+=== /a.ts ===
+export const a = "a";
+>a : Symbol(a, Decl(a.ts, 0, 12))
+
diff --git a/tests/baselines/reference/bundlerSyntaxRestrictions.types b/tests/baselines/reference/bundlerSyntaxRestrictions.types
new file mode 100644
index 0000000000000..ce832fdb57aa5
--- /dev/null
+++ b/tests/baselines/reference/bundlerSyntaxRestrictions.types
@@ -0,0 +1,37 @@
+=== /node_modules/@types/node/index.d.ts ===
+declare var require: (...args: any[]) => any;
+>require : (...args: any[]) => any
+>args : any[]
+
+=== /mainJs.js ===
+import {} from "./a";
+import("./a");
+>import("./a") : Promise<typeof import("/a")>
+>"./a" : "./a"
+
+const _ = require("./a"); // No resolution
+>_ : any
+>require("./a") : any
+>require : (...args: any[]) => any
+>"./a" : "./a"
+
+_.a; // any
+>_.a : any
+>_ : any
+>a : any
+
+=== /main.ts ===
+import {} from "./a";
+import _ = require("./a"); // Error
+>_ : typeof _
+
+export = {}; // Error
+>{} : {}
+
+export {};
+
+=== /a.ts ===
+export const a = "a";
+>a : "a"
+>"a" : "a"
+
diff --git a/tests/baselines/reference/config/commandLineParsing/parseCommandLine/Parse empty options of --moduleResolution.js b/tests/baselines/reference/config/commandLineParsing/parseCommandLine/Parse empty options of --moduleResolution.js
index fb361238364f5..562f23f1a7748 100644
--- a/tests/baselines/reference/config/commandLineParsing/parseCommandLine/Parse empty options of --moduleResolution.js	
+++ b/tests/baselines/reference/config/commandLineParsing/parseCommandLine/Parse empty options of --moduleResolution.js	
@@ -7,4 +7,4 @@ FileNames::
 0.ts
 Errors::
 error TS6044: Compiler option 'moduleResolution' expects an argument.
-error TS6046: Argument for '--moduleResolution' option must be: 'node', 'classic', 'node16', 'nodenext'.
+error TS6046: Argument for '--moduleResolution' option must be: 'node', 'classic', 'node16', 'nodenext', 'bundler'.
diff --git a/tests/baselines/reference/config/initTSConfig/Default initialized TSConfig/tsconfig.json b/tests/baselines/reference/config/initTSConfig/Default initialized TSConfig/tsconfig.json
index 19844ec8065fc..5eaa44daaec1e 100644
--- a/tests/baselines/reference/config/initTSConfig/Default initialized TSConfig/tsconfig.json	
+++ b/tests/baselines/reference/config/initTSConfig/Default initialized TSConfig/tsconfig.json	
@@ -35,6 +35,10 @@
     // "types": [],                                      /* Specify type package names to be included without being referenced in a source file. */
     // "allowUmdGlobalAccess": true,                     /* Allow accessing UMD globals from modules. */
     // "moduleSuffixes": [],                             /* List of file name suffixes to search when resolving a module. */
+    // "allowImportingTsExtensions": true,               /* Allow imports to include TypeScript file extensions. Requires '--moduleResolution bundler' and either '--noEmit' or '--emitDeclarationOnly' to be set. */
+    // "resolvePackageJsonExports": true,                /* Use the package.json 'exports' field when resolving package imports. */
+    // "resolvePackageJsonImports": true,                /* Use the package.json 'imports' field when resolving imports. */
+    // "customConditions": [],                           /* Conditions to set in addition to the resolver-specific defaults when resolving imports. */
     // "resolveJsonModule": true,                        /* Enable importing .json files. */
     // "noResolve": true,                                /* Disallow 'import's, 'require's or '<reference>'s from expanding the number of files TypeScript should add to a project. */
 
diff --git a/tests/baselines/reference/config/initTSConfig/Initialized TSConfig with --help/tsconfig.json b/tests/baselines/reference/config/initTSConfig/Initialized TSConfig with --help/tsconfig.json
index 19844ec8065fc..5eaa44daaec1e 100644
--- a/tests/baselines/reference/config/initTSConfig/Initialized TSConfig with --help/tsconfig.json	
+++ b/tests/baselines/reference/config/initTSConfig/Initialized TSConfig with --help/tsconfig.json	
@@ -35,6 +35,10 @@
     // "types": [],                                      /* Specify type package names to be included without being referenced in a source file. */
     // "allowUmdGlobalAccess": true,                     /* Allow accessing UMD globals from modules. */
     // "moduleSuffixes": [],                             /* List of file name suffixes to search when resolving a module. */
+    // "allowImportingTsExtensions": true,               /* Allow imports to include TypeScript file extensions. Requires '--moduleResolution bundler' and either '--noEmit' or '--emitDeclarationOnly' to be set. */
+    // "resolvePackageJsonExports": true,                /* Use the package.json 'exports' field when resolving package imports. */
+    // "resolvePackageJsonImports": true,                /* Use the package.json 'imports' field when resolving imports. */
+    // "customConditions": [],                           /* Conditions to set in addition to the resolver-specific defaults when resolving imports. */
     // "resolveJsonModule": true,                        /* Enable importing .json files. */
     // "noResolve": true,                                /* Disallow 'import's, 'require's or '<reference>'s from expanding the number of files TypeScript should add to a project. */
 
diff --git a/tests/baselines/reference/config/initTSConfig/Initialized TSConfig with --watch/tsconfig.json b/tests/baselines/reference/config/initTSConfig/Initialized TSConfig with --watch/tsconfig.json
index 19844ec8065fc..5eaa44daaec1e 100644
--- a/tests/baselines/reference/config/initTSConfig/Initialized TSConfig with --watch/tsconfig.json	
+++ b/tests/baselines/reference/config/initTSConfig/Initialized TSConfig with --watch/tsconfig.json	
@@ -35,6 +35,10 @@
     // "types": [],                                      /* Specify type package names to be included without being referenced in a source file. */
     // "allowUmdGlobalAccess": true,                     /* Allow accessing UMD globals from modules. */
     // "moduleSuffixes": [],                             /* List of file name suffixes to search when resolving a module. */
+    // "allowImportingTsExtensions": true,               /* Allow imports to include TypeScript file extensions. Requires '--moduleResolution bundler' and either '--noEmit' or '--emitDeclarationOnly' to be set. */
+    // "resolvePackageJsonExports": true,                /* Use the package.json 'exports' field when resolving package imports. */
+    // "resolvePackageJsonImports": true,                /* Use the package.json 'imports' field when resolving imports. */
+    // "customConditions": [],                           /* Conditions to set in addition to the resolver-specific defaults when resolving imports. */
     // "resolveJsonModule": true,                        /* Enable importing .json files. */
     // "noResolve": true,                                /* Disallow 'import's, 'require's or '<reference>'s from expanding the number of files TypeScript should add to a project. */
 
diff --git a/tests/baselines/reference/config/initTSConfig/Initialized TSConfig with advanced options/tsconfig.json b/tests/baselines/reference/config/initTSConfig/Initialized TSConfig with advanced options/tsconfig.json
index 6e28e016bd11d..00903ad0c38a1 100644
--- a/tests/baselines/reference/config/initTSConfig/Initialized TSConfig with advanced options/tsconfig.json	
+++ b/tests/baselines/reference/config/initTSConfig/Initialized TSConfig with advanced options/tsconfig.json	
@@ -35,6 +35,10 @@
     // "types": [],                                      /* Specify type package names to be included without being referenced in a source file. */
     // "allowUmdGlobalAccess": true,                     /* Allow accessing UMD globals from modules. */
     // "moduleSuffixes": [],                             /* List of file name suffixes to search when resolving a module. */
+    // "allowImportingTsExtensions": true,               /* Allow imports to include TypeScript file extensions. Requires '--moduleResolution bundler' and either '--noEmit' or '--emitDeclarationOnly' to be set. */
+    // "resolvePackageJsonExports": true,                /* Use the package.json 'exports' field when resolving package imports. */
+    // "resolvePackageJsonImports": true,                /* Use the package.json 'imports' field when resolving imports. */
+    // "customConditions": [],                           /* Conditions to set in addition to the resolver-specific defaults when resolving imports. */
     // "resolveJsonModule": true,                        /* Enable importing .json files. */
     // "noResolve": true,                                /* Disallow 'import's, 'require's or '<reference>'s from expanding the number of files TypeScript should add to a project. */
 
diff --git a/tests/baselines/reference/config/initTSConfig/Initialized TSConfig with boolean value compiler options/tsconfig.json b/tests/baselines/reference/config/initTSConfig/Initialized TSConfig with boolean value compiler options/tsconfig.json
index d73dbd191a220..07e8da2a6e437 100644
--- a/tests/baselines/reference/config/initTSConfig/Initialized TSConfig with boolean value compiler options/tsconfig.json	
+++ b/tests/baselines/reference/config/initTSConfig/Initialized TSConfig with boolean value compiler options/tsconfig.json	
@@ -35,6 +35,10 @@
     // "types": [],                                      /* Specify type package names to be included without being referenced in a source file. */
     // "allowUmdGlobalAccess": true,                     /* Allow accessing UMD globals from modules. */
     // "moduleSuffixes": [],                             /* List of file name suffixes to search when resolving a module. */
+    // "allowImportingTsExtensions": true,               /* Allow imports to include TypeScript file extensions. Requires '--moduleResolution bundler' and either '--noEmit' or '--emitDeclarationOnly' to be set. */
+    // "resolvePackageJsonExports": true,                /* Use the package.json 'exports' field when resolving package imports. */
+    // "resolvePackageJsonImports": true,                /* Use the package.json 'imports' field when resolving imports. */
+    // "customConditions": [],                           /* Conditions to set in addition to the resolver-specific defaults when resolving imports. */
     // "resolveJsonModule": true,                        /* Enable importing .json files. */
     // "noResolve": true,                                /* Disallow 'import's, 'require's or '<reference>'s from expanding the number of files TypeScript should add to a project. */
 
diff --git a/tests/baselines/reference/config/initTSConfig/Initialized TSConfig with enum value compiler options/tsconfig.json b/tests/baselines/reference/config/initTSConfig/Initialized TSConfig with enum value compiler options/tsconfig.json
index c4c554e65dffb..ff2c5a0a7e672 100644
--- a/tests/baselines/reference/config/initTSConfig/Initialized TSConfig with enum value compiler options/tsconfig.json	
+++ b/tests/baselines/reference/config/initTSConfig/Initialized TSConfig with enum value compiler options/tsconfig.json	
@@ -35,6 +35,10 @@
     // "types": [],                                      /* Specify type package names to be included without being referenced in a source file. */
     // "allowUmdGlobalAccess": true,                     /* Allow accessing UMD globals from modules. */
     // "moduleSuffixes": [],                             /* List of file name suffixes to search when resolving a module. */
+    // "allowImportingTsExtensions": true,               /* Allow imports to include TypeScript file extensions. Requires '--moduleResolution bundler' and either '--noEmit' or '--emitDeclarationOnly' to be set. */
+    // "resolvePackageJsonExports": true,                /* Use the package.json 'exports' field when resolving package imports. */
+    // "resolvePackageJsonImports": true,                /* Use the package.json 'imports' field when resolving imports. */
+    // "customConditions": [],                           /* Conditions to set in addition to the resolver-specific defaults when resolving imports. */
     // "resolveJsonModule": true,                        /* Enable importing .json files. */
     // "noResolve": true,                                /* Disallow 'import's, 'require's or '<reference>'s from expanding the number of files TypeScript should add to a project. */
 
diff --git a/tests/baselines/reference/config/initTSConfig/Initialized TSConfig with files options/tsconfig.json b/tests/baselines/reference/config/initTSConfig/Initialized TSConfig with files options/tsconfig.json
index 2368ed9c35291..3955bbd422ede 100644
--- a/tests/baselines/reference/config/initTSConfig/Initialized TSConfig with files options/tsconfig.json	
+++ b/tests/baselines/reference/config/initTSConfig/Initialized TSConfig with files options/tsconfig.json	
@@ -35,6 +35,10 @@
     // "types": [],                                      /* Specify type package names to be included without being referenced in a source file. */
     // "allowUmdGlobalAccess": true,                     /* Allow accessing UMD globals from modules. */
     // "moduleSuffixes": [],                             /* List of file name suffixes to search when resolving a module. */
+    // "allowImportingTsExtensions": true,               /* Allow imports to include TypeScript file extensions. Requires '--moduleResolution bundler' and either '--noEmit' or '--emitDeclarationOnly' to be set. */
+    // "resolvePackageJsonExports": true,                /* Use the package.json 'exports' field when resolving package imports. */
+    // "resolvePackageJsonImports": true,                /* Use the package.json 'imports' field when resolving imports. */
+    // "customConditions": [],                           /* Conditions to set in addition to the resolver-specific defaults when resolving imports. */
     // "resolveJsonModule": true,                        /* Enable importing .json files. */
     // "noResolve": true,                                /* Disallow 'import's, 'require's or '<reference>'s from expanding the number of files TypeScript should add to a project. */
 
diff --git a/tests/baselines/reference/config/initTSConfig/Initialized TSConfig with incorrect compiler option value/tsconfig.json b/tests/baselines/reference/config/initTSConfig/Initialized TSConfig with incorrect compiler option value/tsconfig.json
index 195f29bcb8708..f635f645ea08b 100644
--- a/tests/baselines/reference/config/initTSConfig/Initialized TSConfig with incorrect compiler option value/tsconfig.json	
+++ b/tests/baselines/reference/config/initTSConfig/Initialized TSConfig with incorrect compiler option value/tsconfig.json	
@@ -35,6 +35,10 @@
     // "types": [],                                      /* Specify type package names to be included without being referenced in a source file. */
     // "allowUmdGlobalAccess": true,                     /* Allow accessing UMD globals from modules. */
     // "moduleSuffixes": [],                             /* List of file name suffixes to search when resolving a module. */
+    // "allowImportingTsExtensions": true,               /* Allow imports to include TypeScript file extensions. Requires '--moduleResolution bundler' and either '--noEmit' or '--emitDeclarationOnly' to be set. */
+    // "resolvePackageJsonExports": true,                /* Use the package.json 'exports' field when resolving package imports. */
+    // "resolvePackageJsonImports": true,                /* Use the package.json 'imports' field when resolving imports. */
+    // "customConditions": [],                           /* Conditions to set in addition to the resolver-specific defaults when resolving imports. */
     // "resolveJsonModule": true,                        /* Enable importing .json files. */
     // "noResolve": true,                                /* Disallow 'import's, 'require's or '<reference>'s from expanding the number of files TypeScript should add to a project. */
 
diff --git a/tests/baselines/reference/config/initTSConfig/Initialized TSConfig with incorrect compiler option/tsconfig.json b/tests/baselines/reference/config/initTSConfig/Initialized TSConfig with incorrect compiler option/tsconfig.json
index 19844ec8065fc..5eaa44daaec1e 100644
--- a/tests/baselines/reference/config/initTSConfig/Initialized TSConfig with incorrect compiler option/tsconfig.json	
+++ b/tests/baselines/reference/config/initTSConfig/Initialized TSConfig with incorrect compiler option/tsconfig.json	
@@ -35,6 +35,10 @@
     // "types": [],                                      /* Specify type package names to be included without being referenced in a source file. */
     // "allowUmdGlobalAccess": true,                     /* Allow accessing UMD globals from modules. */
     // "moduleSuffixes": [],                             /* List of file name suffixes to search when resolving a module. */
+    // "allowImportingTsExtensions": true,               /* Allow imports to include TypeScript file extensions. Requires '--moduleResolution bundler' and either '--noEmit' or '--emitDeclarationOnly' to be set. */
+    // "resolvePackageJsonExports": true,                /* Use the package.json 'exports' field when resolving package imports. */
+    // "resolvePackageJsonImports": true,                /* Use the package.json 'imports' field when resolving imports. */
+    // "customConditions": [],                           /* Conditions to set in addition to the resolver-specific defaults when resolving imports. */
     // "resolveJsonModule": true,                        /* Enable importing .json files. */
     // "noResolve": true,                                /* Disallow 'import's, 'require's or '<reference>'s from expanding the number of files TypeScript should add to a project. */
 
diff --git a/tests/baselines/reference/config/initTSConfig/Initialized TSConfig with list compiler options with enum value/tsconfig.json b/tests/baselines/reference/config/initTSConfig/Initialized TSConfig with list compiler options with enum value/tsconfig.json
index fe6fd06aa610a..ed7f34f5e6557 100644
--- a/tests/baselines/reference/config/initTSConfig/Initialized TSConfig with list compiler options with enum value/tsconfig.json	
+++ b/tests/baselines/reference/config/initTSConfig/Initialized TSConfig with list compiler options with enum value/tsconfig.json	
@@ -35,6 +35,10 @@
     // "types": [],                                      /* Specify type package names to be included without being referenced in a source file. */
     // "allowUmdGlobalAccess": true,                     /* Allow accessing UMD globals from modules. */
     // "moduleSuffixes": [],                             /* List of file name suffixes to search when resolving a module. */
+    // "allowImportingTsExtensions": true,               /* Allow imports to include TypeScript file extensions. Requires '--moduleResolution bundler' and either '--noEmit' or '--emitDeclarationOnly' to be set. */
+    // "resolvePackageJsonExports": true,                /* Use the package.json 'exports' field when resolving package imports. */
+    // "resolvePackageJsonImports": true,                /* Use the package.json 'imports' field when resolving imports. */
+    // "customConditions": [],                           /* Conditions to set in addition to the resolver-specific defaults when resolving imports. */
     // "resolveJsonModule": true,                        /* Enable importing .json files. */
     // "noResolve": true,                                /* Disallow 'import's, 'require's or '<reference>'s from expanding the number of files TypeScript should add to a project. */
 
diff --git a/tests/baselines/reference/config/initTSConfig/Initialized TSConfig with list compiler options/tsconfig.json b/tests/baselines/reference/config/initTSConfig/Initialized TSConfig with list compiler options/tsconfig.json
index 12daecbe8ed51..cc9d87c258ddb 100644
--- a/tests/baselines/reference/config/initTSConfig/Initialized TSConfig with list compiler options/tsconfig.json	
+++ b/tests/baselines/reference/config/initTSConfig/Initialized TSConfig with list compiler options/tsconfig.json	
@@ -35,6 +35,10 @@
     "types": ["jquery","mocha"],                         /* Specify type package names to be included without being referenced in a source file. */
     // "allowUmdGlobalAccess": true,                     /* Allow accessing UMD globals from modules. */
     // "moduleSuffixes": [],                             /* List of file name suffixes to search when resolving a module. */
+    // "allowImportingTsExtensions": true,               /* Allow imports to include TypeScript file extensions. Requires '--moduleResolution bundler' and either '--noEmit' or '--emitDeclarationOnly' to be set. */
+    // "resolvePackageJsonExports": true,                /* Use the package.json 'exports' field when resolving package imports. */
+    // "resolvePackageJsonImports": true,                /* Use the package.json 'imports' field when resolving imports. */
+    // "customConditions": [],                           /* Conditions to set in addition to the resolver-specific defaults when resolving imports. */
     // "resolveJsonModule": true,                        /* Enable importing .json files. */
     // "noResolve": true,                                /* Disallow 'import's, 'require's or '<reference>'s from expanding the number of files TypeScript should add to a project. */
 
diff --git a/tests/baselines/reference/config/showConfig/Shows tsconfig for single option/allowImportingTsExtensions/tsconfig.json b/tests/baselines/reference/config/showConfig/Shows tsconfig for single option/allowImportingTsExtensions/tsconfig.json
new file mode 100644
index 0000000000000..88c95f9eb8307
--- /dev/null
+++ b/tests/baselines/reference/config/showConfig/Shows tsconfig for single option/allowImportingTsExtensions/tsconfig.json	
@@ -0,0 +1,5 @@
+{
+    "compilerOptions": {
+        "allowImportingTsExtensions": true
+    }
+}
diff --git a/tests/baselines/reference/config/showConfig/Shows tsconfig for single option/customConditions/tsconfig.json b/tests/baselines/reference/config/showConfig/Shows tsconfig for single option/customConditions/tsconfig.json
new file mode 100644
index 0000000000000..e121ee76bc105
--- /dev/null
+++ b/tests/baselines/reference/config/showConfig/Shows tsconfig for single option/customConditions/tsconfig.json	
@@ -0,0 +1,5 @@
+{
+    "compilerOptions": {
+        "customConditions": []
+    }
+}
diff --git a/tests/baselines/reference/config/showConfig/Shows tsconfig for single option/resolvePackageJsonExports/tsconfig.json b/tests/baselines/reference/config/showConfig/Shows tsconfig for single option/resolvePackageJsonExports/tsconfig.json
new file mode 100644
index 0000000000000..4dc0efaa783ba
--- /dev/null
+++ b/tests/baselines/reference/config/showConfig/Shows tsconfig for single option/resolvePackageJsonExports/tsconfig.json	
@@ -0,0 +1,5 @@
+{
+    "compilerOptions": {
+        "resolvePackageJsonExports": true
+    }
+}
diff --git a/tests/baselines/reference/config/showConfig/Shows tsconfig for single option/resolvePackageJsonImports/tsconfig.json b/tests/baselines/reference/config/showConfig/Shows tsconfig for single option/resolvePackageJsonImports/tsconfig.json
new file mode 100644
index 0000000000000..a9e8a0f9e1faa
--- /dev/null
+++ b/tests/baselines/reference/config/showConfig/Shows tsconfig for single option/resolvePackageJsonImports/tsconfig.json	
@@ -0,0 +1,5 @@
+{
+    "compilerOptions": {
+        "resolvePackageJsonImports": true
+    }
+}
diff --git a/tests/baselines/reference/customConditions(resolvepackagejsonexports=false).js b/tests/baselines/reference/customConditions(resolvepackagejsonexports=false).js
new file mode 100644
index 0000000000000..1ac29a4a032d3
--- /dev/null
+++ b/tests/baselines/reference/customConditions(resolvepackagejsonexports=false).js
@@ -0,0 +1,33 @@
+//// [tests/cases/conformance/moduleResolution/customConditions.ts] ////
+
+//// [package.json]
+{
+    "name": "lodash",
+    "version": "1.0.0",
+    "main": "index.js",
+    "exports": {
+        "browser": "./browser.js",
+        "webpack": "./webpack.js",
+        "default": "./index.js"
+    }
+}
+
+//// [index.d.ts]
+declare const _: "index";
+export = _;
+
+//// [browser.d.ts]
+declare const _: "browser";
+export default _;
+
+//// [webpack.d.ts]
+declare const _: "webpack";
+export = _;
+
+//// [index.ts]
+import _ from "lodash";
+
+
+//// [index.js]
+"use strict";
+Object.defineProperty(exports, "__esModule", { value: true });
diff --git a/tests/baselines/reference/customConditions(resolvepackagejsonexports=false).symbols b/tests/baselines/reference/customConditions(resolvepackagejsonexports=false).symbols
new file mode 100644
index 0000000000000..2b8cae85a8c11
--- /dev/null
+++ b/tests/baselines/reference/customConditions(resolvepackagejsonexports=false).symbols
@@ -0,0 +1,25 @@
+=== /node_modules/lodash/index.d.ts ===
+declare const _: "index";
+>_ : Symbol(_, Decl(index.d.ts, 0, 13))
+
+export = _;
+>_ : Symbol(_, Decl(index.d.ts, 0, 13))
+
+=== /node_modules/lodash/browser.d.ts ===
+declare const _: "browser";
+>_ : Symbol(_, Decl(browser.d.ts, 0, 13))
+
+export default _;
+>_ : Symbol(_, Decl(browser.d.ts, 0, 13))
+
+=== /node_modules/lodash/webpack.d.ts ===
+declare const _: "webpack";
+>_ : Symbol(_, Decl(webpack.d.ts, 0, 13))
+
+export = _;
+>_ : Symbol(_, Decl(webpack.d.ts, 0, 13))
+
+=== /index.ts ===
+import _ from "lodash";
+>_ : Symbol(_, Decl(index.ts, 0, 6))
+
diff --git a/tests/baselines/reference/customConditions(resolvepackagejsonexports=false).trace.json b/tests/baselines/reference/customConditions(resolvepackagejsonexports=false).trace.json
new file mode 100644
index 0000000000000..1b85a4d6fcaf1
--- /dev/null
+++ b/tests/baselines/reference/customConditions(resolvepackagejsonexports=false).trace.json
@@ -0,0 +1,22 @@
+[
+    "======== Resolving module 'lodash' from '/index.ts'. ========",
+    "Explicitly specified module resolution kind: 'Bundler'.",
+    "File '/package.json' does not exist.",
+    "Loading module 'lodash' from 'node_modules' folder, target file types: TypeScript, JavaScript, Declaration, JSON.",
+    "Found 'package.json' at '/node_modules/lodash/package.json'.",
+    "File '/node_modules/lodash.ts' does not exist.",
+    "File '/node_modules/lodash.tsx' does not exist.",
+    "File '/node_modules/lodash.d.ts' does not exist.",
+    "'package.json' does not have a 'typesVersions' field.",
+    "'package.json' does not have a 'typings' field.",
+    "'package.json' does not have a 'types' field.",
+    "'package.json' has 'main' field 'index.js' that references '/node_modules/lodash/index.js'.",
+    "File '/node_modules/lodash/index.js' does not exist.",
+    "Loading module as file / folder, candidate module location '/node_modules/lodash/index.js', target file types: TypeScript, Declaration.",
+    "File name '/node_modules/lodash/index.js' has a '.js' extension - stripping it.",
+    "File '/node_modules/lodash/index.ts' does not exist.",
+    "File '/node_modules/lodash/index.tsx' does not exist.",
+    "File '/node_modules/lodash/index.d.ts' exist - use it as a name resolution result.",
+    "Resolving real path for '/node_modules/lodash/index.d.ts', result '/node_modules/lodash/index.d.ts'.",
+    "======== Module name 'lodash' was successfully resolved to '/node_modules/lodash/index.d.ts' with Package ID 'lodash/index.d.ts@1.0.0'. ========"
+]
\ No newline at end of file
diff --git a/tests/baselines/reference/customConditions(resolvepackagejsonexports=false).types b/tests/baselines/reference/customConditions(resolvepackagejsonexports=false).types
new file mode 100644
index 0000000000000..fd913f77aaf75
--- /dev/null
+++ b/tests/baselines/reference/customConditions(resolvepackagejsonexports=false).types
@@ -0,0 +1,25 @@
+=== /node_modules/lodash/index.d.ts ===
+declare const _: "index";
+>_ : "index"
+
+export = _;
+>_ : "index"
+
+=== /node_modules/lodash/browser.d.ts ===
+declare const _: "browser";
+>_ : "browser"
+
+export default _;
+>_ : "browser"
+
+=== /node_modules/lodash/webpack.d.ts ===
+declare const _: "webpack";
+>_ : "webpack"
+
+export = _;
+>_ : "webpack"
+
+=== /index.ts ===
+import _ from "lodash";
+>_ : "index"
+
diff --git a/tests/baselines/reference/customConditions(resolvepackagejsonexports=true).js b/tests/baselines/reference/customConditions(resolvepackagejsonexports=true).js
new file mode 100644
index 0000000000000..1ac29a4a032d3
--- /dev/null
+++ b/tests/baselines/reference/customConditions(resolvepackagejsonexports=true).js
@@ -0,0 +1,33 @@
+//// [tests/cases/conformance/moduleResolution/customConditions.ts] ////
+
+//// [package.json]
+{
+    "name": "lodash",
+    "version": "1.0.0",
+    "main": "index.js",
+    "exports": {
+        "browser": "./browser.js",
+        "webpack": "./webpack.js",
+        "default": "./index.js"
+    }
+}
+
+//// [index.d.ts]
+declare const _: "index";
+export = _;
+
+//// [browser.d.ts]
+declare const _: "browser";
+export default _;
+
+//// [webpack.d.ts]
+declare const _: "webpack";
+export = _;
+
+//// [index.ts]
+import _ from "lodash";
+
+
+//// [index.js]
+"use strict";
+Object.defineProperty(exports, "__esModule", { value: true });
diff --git a/tests/baselines/reference/customConditions(resolvepackagejsonexports=true).symbols b/tests/baselines/reference/customConditions(resolvepackagejsonexports=true).symbols
new file mode 100644
index 0000000000000..2b8cae85a8c11
--- /dev/null
+++ b/tests/baselines/reference/customConditions(resolvepackagejsonexports=true).symbols
@@ -0,0 +1,25 @@
+=== /node_modules/lodash/index.d.ts ===
+declare const _: "index";
+>_ : Symbol(_, Decl(index.d.ts, 0, 13))
+
+export = _;
+>_ : Symbol(_, Decl(index.d.ts, 0, 13))
+
+=== /node_modules/lodash/browser.d.ts ===
+declare const _: "browser";
+>_ : Symbol(_, Decl(browser.d.ts, 0, 13))
+
+export default _;
+>_ : Symbol(_, Decl(browser.d.ts, 0, 13))
+
+=== /node_modules/lodash/webpack.d.ts ===
+declare const _: "webpack";
+>_ : Symbol(_, Decl(webpack.d.ts, 0, 13))
+
+export = _;
+>_ : Symbol(_, Decl(webpack.d.ts, 0, 13))
+
+=== /index.ts ===
+import _ from "lodash";
+>_ : Symbol(_, Decl(index.ts, 0, 6))
+
diff --git a/tests/baselines/reference/customConditions(resolvepackagejsonexports=true).trace.json b/tests/baselines/reference/customConditions(resolvepackagejsonexports=true).trace.json
new file mode 100644
index 0000000000000..2019c28fc9f0d
--- /dev/null
+++ b/tests/baselines/reference/customConditions(resolvepackagejsonexports=true).trace.json
@@ -0,0 +1,16 @@
+[
+    "======== Resolving module 'lodash' from '/index.ts'. ========",
+    "Explicitly specified module resolution kind: 'Bundler'.",
+    "File '/package.json' does not exist.",
+    "Loading module 'lodash' from 'node_modules' folder, target file types: TypeScript, JavaScript, Declaration, JSON.",
+    "Found 'package.json' at '/node_modules/lodash/package.json'.",
+    "Saw non-matching condition 'browser'.",
+    "Matched 'exports' condition 'webpack'.",
+    "Using 'exports' subpath '.' with target './webpack.js'.",
+    "File name '/node_modules/lodash/webpack.js' has a '.js' extension - stripping it.",
+    "File '/node_modules/lodash/webpack.ts' does not exist.",
+    "File '/node_modules/lodash/webpack.tsx' does not exist.",
+    "File '/node_modules/lodash/webpack.d.ts' exist - use it as a name resolution result.",
+    "Resolving real path for '/node_modules/lodash/webpack.d.ts', result '/node_modules/lodash/webpack.d.ts'.",
+    "======== Module name 'lodash' was successfully resolved to '/node_modules/lodash/webpack.d.ts' with Package ID 'lodash/webpack.d.ts@1.0.0'. ========"
+]
\ No newline at end of file
diff --git a/tests/baselines/reference/customConditions(resolvepackagejsonexports=true).types b/tests/baselines/reference/customConditions(resolvepackagejsonexports=true).types
new file mode 100644
index 0000000000000..4ab420533b366
--- /dev/null
+++ b/tests/baselines/reference/customConditions(resolvepackagejsonexports=true).types
@@ -0,0 +1,25 @@
+=== /node_modules/lodash/index.d.ts ===
+declare const _: "index";
+>_ : "index"
+
+export = _;
+>_ : "index"
+
+=== /node_modules/lodash/browser.d.ts ===
+declare const _: "browser";
+>_ : "browser"
+
+export default _;
+>_ : "browser"
+
+=== /node_modules/lodash/webpack.d.ts ===
+declare const _: "webpack";
+>_ : "webpack"
+
+export = _;
+>_ : "webpack"
+
+=== /index.ts ===
+import _ from "lodash";
+>_ : "webpack"
+
diff --git a/tests/baselines/reference/extensionLoadingPriority(moduleresolution=bundler).symbols b/tests/baselines/reference/extensionLoadingPriority(moduleresolution=bundler).symbols
new file mode 100644
index 0000000000000..19522bf41394c
--- /dev/null
+++ b/tests/baselines/reference/extensionLoadingPriority(moduleresolution=bundler).symbols
@@ -0,0 +1,23 @@
+=== /project/a.js ===
+
+export default "a.js";
+
+=== /project/a.js.js ===
+
+export default "a.js.js";
+
+=== /project/dir/index.ts ===
+
+export default "dir/index.ts";
+
+=== /project/dir.js ===
+
+export default "dir.js";
+
+=== /project/b.ts ===
+import a from "./a.js";
+>a : Symbol(a, Decl(b.ts, 0, 6))
+
+import dir from "./dir";
+>dir : Symbol(dir, Decl(b.ts, 1, 6))
+
diff --git a/tests/baselines/reference/extensionLoadingPriority(moduleresolution=bundler).types b/tests/baselines/reference/extensionLoadingPriority(moduleresolution=bundler).types
new file mode 100644
index 0000000000000..b398b344d7017
--- /dev/null
+++ b/tests/baselines/reference/extensionLoadingPriority(moduleresolution=bundler).types
@@ -0,0 +1,23 @@
+=== /project/a.js ===
+
+export default "a.js";
+
+=== /project/a.js.js ===
+
+export default "a.js.js";
+
+=== /project/dir/index.ts ===
+
+export default "dir/index.ts";
+
+=== /project/dir.js ===
+
+export default "dir.js";
+
+=== /project/b.ts ===
+import a from "./a.js";
+>a : "a.js"
+
+import dir from "./dir";
+>dir : "dir.js"
+
diff --git a/tests/baselines/reference/moduleResolution/baseUrl-without-path-mappings-or-rootDirs.js b/tests/baselines/reference/moduleResolution/baseUrl-without-path-mappings-or-rootDirs.js
index 7fc2f4fe6403b..3b79ca68b2515 100644
--- a/tests/baselines/reference/moduleResolution/baseUrl-without-path-mappings-or-rootDirs.js
+++ b/tests/baselines/reference/moduleResolution/baseUrl-without-path-mappings-or-rootDirs.js
@@ -12,7 +12,8 @@ Resolution:: {
   "resolvedModule": {
     "resolvedFileName": "/root/folder2/file2.ts",
     "extension": ".ts",
-    "isExternalLibraryImport": false
+    "isExternalLibraryImport": false,
+    "resolvedUsingTsExtension": false
   }
 }
 
@@ -21,7 +22,8 @@ Resolution:: {
   "resolvedModule": {
     "resolvedFileName": "/root/folder2/file3.ts",
     "extension": ".ts",
-    "isExternalLibraryImport": false
+    "isExternalLibraryImport": false,
+    "resolvedUsingTsExtension": false
   }
 }
 
@@ -30,7 +32,8 @@ Resolution:: {
   "resolvedModule": {
     "resolvedFileName": "/root/folder1/file1.ts",
     "extension": ".ts",
-    "isExternalLibraryImport": false
+    "isExternalLibraryImport": false,
+    "resolvedUsingTsExtension": false
   }
 }
 
@@ -39,7 +42,8 @@ Resolution:: {
   "resolvedModule": {
     "resolvedFileName": "/root/folder2/file2.ts",
     "extension": ".ts",
-    "isExternalLibraryImport": false
+    "isExternalLibraryImport": false,
+    "resolvedUsingTsExtension": false
   }
 }
 
@@ -48,7 +52,8 @@ Resolution:: {
   "resolvedModule": {
     "resolvedFileName": "/root/folder2/file3.ts",
     "extension": ".ts",
-    "isExternalLibraryImport": false
+    "isExternalLibraryImport": false,
+    "resolvedUsingTsExtension": false
   }
 }
 
@@ -57,7 +62,8 @@ Resolution:: {
   "resolvedModule": {
     "resolvedFileName": "/root/folder1/file1.ts",
     "extension": ".ts",
-    "isExternalLibraryImport": false
+    "isExternalLibraryImport": false,
+    "resolvedUsingTsExtension": false
   }
 }
 
@@ -75,7 +81,8 @@ Resolution:: {
   "resolvedModule": {
     "resolvedFileName": "/root/folder2/file2.ts",
     "extension": ".ts",
-    "isExternalLibraryImport": false
+    "isExternalLibraryImport": false,
+    "resolvedUsingTsExtension": false
   }
 }
 
@@ -84,7 +91,8 @@ Resolution:: {
   "resolvedModule": {
     "resolvedFileName": "/root/folder2/file3.ts",
     "extension": ".ts",
-    "isExternalLibraryImport": false
+    "isExternalLibraryImport": false,
+    "resolvedUsingTsExtension": false
   }
 }
 
@@ -93,7 +101,8 @@ Resolution:: {
   "resolvedModule": {
     "resolvedFileName": "/root/folder1/file1.ts",
     "extension": ".ts",
-    "isExternalLibraryImport": false
+    "isExternalLibraryImport": false,
+    "resolvedUsingTsExtension": false
   }
 }
 
@@ -102,7 +111,8 @@ Resolution:: {
   "resolvedModule": {
     "resolvedFileName": "/root/folder2/file2.ts",
     "extension": ".ts",
-    "isExternalLibraryImport": false
+    "isExternalLibraryImport": false,
+    "resolvedUsingTsExtension": false
   }
 }
 
@@ -111,7 +121,8 @@ Resolution:: {
   "resolvedModule": {
     "resolvedFileName": "/root/folder2/file3.ts",
     "extension": ".ts",
-    "isExternalLibraryImport": false
+    "isExternalLibraryImport": false,
+    "resolvedUsingTsExtension": false
   }
 }
 
@@ -120,6 +131,7 @@ Resolution:: {
   "resolvedModule": {
     "resolvedFileName": "/root/folder1/file1.ts",
     "extension": ".ts",
-    "isExternalLibraryImport": false
+    "isExternalLibraryImport": false,
+    "resolvedUsingTsExtension": false
   }
 }
diff --git a/tests/baselines/reference/moduleResolution/classic-baseUrl-path-mappings.js b/tests/baselines/reference/moduleResolution/classic-baseUrl-path-mappings.js
index 48a7deab2e2d5..70def6c942347 100644
--- a/tests/baselines/reference/moduleResolution/classic-baseUrl-path-mappings.js
+++ b/tests/baselines/reference/moduleResolution/classic-baseUrl-path-mappings.js
@@ -12,7 +12,8 @@ Resolution:: {
   "resolvedModule": {
     "resolvedFileName": "/root/folder1/file1.ts",
     "extension": ".ts",
-    "isExternalLibraryImport": false
+    "isExternalLibraryImport": false,
+    "resolvedUsingTsExtension": false
   }
 }
 
@@ -21,7 +22,8 @@ Resolution:: {
   "resolvedModule": {
     "resolvedFileName": "/root/generated/folder1/file2.ts",
     "extension": ".ts",
-    "isExternalLibraryImport": false
+    "isExternalLibraryImport": false,
+    "resolvedUsingTsExtension": false
   },
   "failedLookupLocations": [
     "/root/folder1/file2.ts",
@@ -35,7 +37,8 @@ Resolution:: {
   "resolvedModule": {
     "resolvedFileName": "/root/generated/folder1/file2.ts",
     "extension": ".ts",
-    "isExternalLibraryImport": false
+    "isExternalLibraryImport": false,
+    "resolvedUsingTsExtension": false
   }
 }
 
@@ -44,7 +47,8 @@ Resolution:: {
   "resolvedModule": {
     "resolvedFileName": "/folder1/file3.ts",
     "extension": ".ts",
-    "isExternalLibraryImport": false
+    "isExternalLibraryImport": false,
+    "resolvedUsingTsExtension": false
   },
   "failedLookupLocations": [
     "/root/folder1/file3.ts",
diff --git a/tests/baselines/reference/moduleResolution/classic-baseUrl.js b/tests/baselines/reference/moduleResolution/classic-baseUrl.js
index 9d1587a3c7bf2..0a9d2f72813fb 100644
--- a/tests/baselines/reference/moduleResolution/classic-baseUrl.js
+++ b/tests/baselines/reference/moduleResolution/classic-baseUrl.js
@@ -12,7 +12,8 @@ Resolution:: {
   "resolvedModule": {
     "resolvedFileName": "/root/x/m1.ts",
     "extension": ".ts",
-    "isExternalLibraryImport": false
+    "isExternalLibraryImport": false,
+    "resolvedUsingTsExtension": false
   }
 }
 
@@ -21,7 +22,8 @@ Resolution:: {
   "resolvedModule": {
     "resolvedFileName": "/m2.ts",
     "extension": ".ts",
-    "isExternalLibraryImport": false
+    "isExternalLibraryImport": false,
+    "resolvedUsingTsExtension": false
   },
   "failedLookupLocations": [
     "/root/x/m2.ts",
@@ -53,7 +55,8 @@ Resolution:: {
   "resolvedModule": {
     "resolvedFileName": "/root/x/m1.ts",
     "extension": ".ts",
-    "isExternalLibraryImport": false
+    "isExternalLibraryImport": false,
+    "resolvedUsingTsExtension": false
   }
 }
 
@@ -62,7 +65,8 @@ Resolution:: {
   "resolvedModule": {
     "resolvedFileName": "/m2.ts",
     "extension": ".ts",
-    "isExternalLibraryImport": false
+    "isExternalLibraryImport": false,
+    "resolvedUsingTsExtension": false
   },
   "failedLookupLocations": [
     "/root/x/m2.ts",
diff --git a/tests/baselines/reference/moduleResolution/classic-rootDirs.js b/tests/baselines/reference/moduleResolution/classic-rootDirs.js
index 7e7d2178995a6..62595ab05cf51 100644
--- a/tests/baselines/reference/moduleResolution/classic-rootDirs.js
+++ b/tests/baselines/reference/moduleResolution/classic-rootDirs.js
@@ -15,7 +15,8 @@ Resolution:: {
   "resolvedModule": {
     "resolvedFileName": "/root/generated/folder1/file2.ts",
     "extension": ".ts",
-    "isExternalLibraryImport": false
+    "isExternalLibraryImport": false,
+    "resolvedUsingTsExtension": false
   },
   "failedLookupLocations": [
     "/root/folder1/file2.ts",
@@ -29,7 +30,8 @@ Resolution:: {
   "resolvedModule": {
     "resolvedFileName": "/root/folder1/file1.ts",
     "extension": ".ts",
-    "isExternalLibraryImport": false
+    "isExternalLibraryImport": false,
+    "resolvedUsingTsExtension": false
   },
   "failedLookupLocations": [
     "/root/generated/folder1/file1.ts",
@@ -43,7 +45,8 @@ Resolution:: {
   "resolvedModule": {
     "resolvedFileName": "/folder1/file1_1.ts",
     "extension": ".ts",
-    "isExternalLibraryImport": false
+    "isExternalLibraryImport": false,
+    "resolvedUsingTsExtension": false
   },
   "failedLookupLocations": [
     "/root/generated/folder2/folder1/file1_1.ts",
diff --git a/tests/baselines/reference/moduleResolution/nested-node-module.js b/tests/baselines/reference/moduleResolution/nested-node-module.js
index 3edb344426c60..c1ba22b9f8397 100644
--- a/tests/baselines/reference/moduleResolution/nested-node-module.js
+++ b/tests/baselines/reference/moduleResolution/nested-node-module.js
@@ -12,7 +12,8 @@ Resolution:: {
   "resolvedModule": {
     "resolvedFileName": "/root/src/libs/guid/dist/guid.d.ts",
     "extension": ".d.ts",
-    "isExternalLibraryImport": false
+    "isExternalLibraryImport": false,
+    "resolvedUsingTsExtension": false
   },
   "failedLookupLocations": [
     "/root/src/libs/guid.ts",
@@ -38,7 +39,8 @@ Resolution:: {
   "resolvedModule": {
     "resolvedFileName": "/root/src/libs/guid/dist/guid.d.ts",
     "extension": ".d.ts",
-    "isExternalLibraryImport": false
+    "isExternalLibraryImport": false,
+    "resolvedUsingTsExtension": false
   },
   "failedLookupLocations": [
     "/root/src/libs/guid.ts",
diff --git a/tests/baselines/reference/moduleResolution/node-baseUrl-path-mappings.js b/tests/baselines/reference/moduleResolution/node-baseUrl-path-mappings.js
index a117b795cc23c..30e9c41445cc7 100644
--- a/tests/baselines/reference/moduleResolution/node-baseUrl-path-mappings.js
+++ b/tests/baselines/reference/moduleResolution/node-baseUrl-path-mappings.js
@@ -24,7 +24,8 @@ Resolution:: {
   "resolvedModule": {
     "resolvedFileName": "/root/folder1/file1.ts",
     "extension": ".ts",
-    "isExternalLibraryImport": false
+    "isExternalLibraryImport": false,
+    "resolvedUsingTsExtension": false
   }
 }
 
@@ -33,7 +34,8 @@ Resolution:: {
   "resolvedModule": {
     "resolvedFileName": "/root/generated/folder1/file2.ts",
     "extension": ".ts",
-    "isExternalLibraryImport": false
+    "isExternalLibraryImport": false,
+    "resolvedUsingTsExtension": false
   },
   "failedLookupLocations": [
     "/root/folder1/file2.ts",
@@ -51,7 +53,8 @@ Resolution:: {
   "resolvedModule": {
     "resolvedFileName": "/root/generated/folder1/file2.ts",
     "extension": ".ts",
-    "isExternalLibraryImport": false
+    "isExternalLibraryImport": false,
+    "resolvedUsingTsExtension": false
   }
 }
 
@@ -60,7 +63,8 @@ Resolution:: {
   "resolvedModule": {
     "resolvedFileName": "/root/generated/folder2/file3/index.d.ts",
     "extension": ".d.ts",
-    "isExternalLibraryImport": false
+    "isExternalLibraryImport": false,
+    "resolvedUsingTsExtension": false
   },
   "failedLookupLocations": [
     "/root/folder2/file3.ts",
@@ -84,7 +88,8 @@ Resolution:: {
   "resolvedModule": {
     "resolvedFileName": "/root/generated/folder2/file4/dist/types.d.ts",
     "extension": ".d.ts",
-    "isExternalLibraryImport": false
+    "isExternalLibraryImport": false,
+    "resolvedUsingTsExtension": false
   },
   "failedLookupLocations": [
     "/root/folder2/file4.ts",
@@ -108,7 +113,8 @@ Resolution:: {
   "resolvedModule": {
     "resolvedFileName": "/root/someanotherfolder/file5/index.d.ts",
     "extension": ".d.ts",
-    "isExternalLibraryImport": false
+    "isExternalLibraryImport": false,
+    "resolvedUsingTsExtension": false
   },
   "failedLookupLocations": [
     "/root/someanotherfolder/file5.ts",
@@ -125,7 +131,8 @@ Resolution:: {
   "resolvedModule": {
     "resolvedFileName": "/root/node_modules/file6.ts",
     "extension": ".ts",
-    "isExternalLibraryImport": true
+    "isExternalLibraryImport": true,
+    "resolvedUsingTsExtension": false
   },
   "failedLookupLocations": [
     "/root/file6.ts",
@@ -182,7 +189,8 @@ Resolution:: {
   "resolvedModule": {
     "resolvedFileName": "/root/folder1/file1.ts",
     "extension": ".ts",
-    "isExternalLibraryImport": false
+    "isExternalLibraryImport": false,
+    "resolvedUsingTsExtension": false
   }
 }
 
@@ -191,7 +199,8 @@ Resolution:: {
   "resolvedModule": {
     "resolvedFileName": "/root/generated/folder1/file2.ts",
     "extension": ".ts",
-    "isExternalLibraryImport": false
+    "isExternalLibraryImport": false,
+    "resolvedUsingTsExtension": false
   },
   "failedLookupLocations": [
     "/root/folder1/file2.ts",
@@ -209,7 +218,8 @@ Resolution:: {
   "resolvedModule": {
     "resolvedFileName": "/root/generated/folder1/file2.ts",
     "extension": ".ts",
-    "isExternalLibraryImport": false
+    "isExternalLibraryImport": false,
+    "resolvedUsingTsExtension": false
   }
 }
 
@@ -218,7 +228,8 @@ Resolution:: {
   "resolvedModule": {
     "resolvedFileName": "/root/generated/folder2/file3/index.d.ts",
     "extension": ".d.ts",
-    "isExternalLibraryImport": false
+    "isExternalLibraryImport": false,
+    "resolvedUsingTsExtension": false
   },
   "failedLookupLocations": [
     "/root/folder2/file3.ts",
@@ -242,7 +253,8 @@ Resolution:: {
   "resolvedModule": {
     "resolvedFileName": "/root/generated/folder2/file4/dist/types.d.ts",
     "extension": ".d.ts",
-    "isExternalLibraryImport": false
+    "isExternalLibraryImport": false,
+    "resolvedUsingTsExtension": false
   },
   "failedLookupLocations": [
     "/root/folder2/file4.ts",
@@ -266,7 +278,8 @@ Resolution:: {
   "resolvedModule": {
     "resolvedFileName": "/root/someanotherfolder/file5/index.d.ts",
     "extension": ".d.ts",
-    "isExternalLibraryImport": false
+    "isExternalLibraryImport": false,
+    "resolvedUsingTsExtension": false
   },
   "failedLookupLocations": [
     "/root/someanotherfolder/file5.ts",
@@ -283,7 +296,8 @@ Resolution:: {
   "resolvedModule": {
     "resolvedFileName": "/root/node_modules/file6.ts",
     "extension": ".ts",
-    "isExternalLibraryImport": true
+    "isExternalLibraryImport": true,
+    "resolvedUsingTsExtension": false
   },
   "failedLookupLocations": [
     "/root/file6.ts",
diff --git a/tests/baselines/reference/moduleResolution/node-baseUrl.js b/tests/baselines/reference/moduleResolution/node-baseUrl.js
index 230672d2b95cb..ecb69b2076974 100644
--- a/tests/baselines/reference/moduleResolution/node-baseUrl.js
+++ b/tests/baselines/reference/moduleResolution/node-baseUrl.js
@@ -21,7 +21,8 @@ Resolution:: {
   "resolvedModule": {
     "resolvedFileName": "/root/m1.ts",
     "extension": ".ts",
-    "isExternalLibraryImport": false
+    "isExternalLibraryImport": false,
+    "resolvedUsingTsExtension": false
   }
 }
 
@@ -30,7 +31,8 @@ Resolution:: {
   "resolvedModule": {
     "resolvedFileName": "/root/m2/index.d.ts",
     "extension": ".d.ts",
-    "isExternalLibraryImport": false
+    "isExternalLibraryImport": false,
+    "resolvedUsingTsExtension": false
   },
   "failedLookupLocations": [
     "/root/m2.ts",
@@ -47,7 +49,8 @@ Resolution:: {
   "resolvedModule": {
     "resolvedFileName": "/root/m3/dist/typings.d.ts",
     "extension": ".d.ts",
-    "isExternalLibraryImport": false
+    "isExternalLibraryImport": false,
+    "resolvedUsingTsExtension": false
   },
   "failedLookupLocations": [
     "/root/m3.ts",
@@ -64,7 +67,8 @@ Resolution:: {
   "resolvedModule": {
     "resolvedFileName": "/root/node_modules/m4.ts",
     "extension": ".ts",
-    "isExternalLibraryImport": true
+    "isExternalLibraryImport": true,
+    "resolvedUsingTsExtension": false
   },
   "failedLookupLocations": [
     "/root/m4.ts",
@@ -121,7 +125,8 @@ Resolution:: {
   "resolvedModule": {
     "resolvedFileName": "/root/m1.ts",
     "extension": ".ts",
-    "isExternalLibraryImport": false
+    "isExternalLibraryImport": false,
+    "resolvedUsingTsExtension": false
   }
 }
 
@@ -130,7 +135,8 @@ Resolution:: {
   "resolvedModule": {
     "resolvedFileName": "/root/m2/index.d.ts",
     "extension": ".d.ts",
-    "isExternalLibraryImport": false
+    "isExternalLibraryImport": false,
+    "resolvedUsingTsExtension": false
   },
   "failedLookupLocations": [
     "/root/m2.ts",
@@ -147,7 +153,8 @@ Resolution:: {
   "resolvedModule": {
     "resolvedFileName": "/root/m3/dist/typings.d.ts",
     "extension": ".d.ts",
-    "isExternalLibraryImport": false
+    "isExternalLibraryImport": false,
+    "resolvedUsingTsExtension": false
   },
   "failedLookupLocations": [
     "/root/m3.ts",
@@ -164,7 +171,8 @@ Resolution:: {
   "resolvedModule": {
     "resolvedFileName": "/root/node_modules/m4.ts",
     "extension": ".ts",
-    "isExternalLibraryImport": true
+    "isExternalLibraryImport": true,
+    "resolvedUsingTsExtension": false
   },
   "failedLookupLocations": [
     "/root/m4.ts",
diff --git a/tests/baselines/reference/moduleResolution/node-rootDirs.js b/tests/baselines/reference/moduleResolution/node-rootDirs.js
index dc033c530c744..c3d8dca2b63f3 100644
--- a/tests/baselines/reference/moduleResolution/node-rootDirs.js
+++ b/tests/baselines/reference/moduleResolution/node-rootDirs.js
@@ -15,7 +15,8 @@ Resolution:: {
   "resolvedModule": {
     "resolvedFileName": "/root/generated/folder1/file2.ts",
     "extension": ".ts",
-    "isExternalLibraryImport": false
+    "isExternalLibraryImport": false,
+    "resolvedUsingTsExtension": false
   },
   "failedLookupLocations": [
     "/root/folder1/file2.ts",
@@ -33,7 +34,8 @@ Resolution:: {
   "resolvedModule": {
     "resolvedFileName": "/root/folder1/file1.ts",
     "extension": ".ts",
-    "isExternalLibraryImport": false
+    "isExternalLibraryImport": false,
+    "resolvedUsingTsExtension": false
   },
   "failedLookupLocations": [
     "/root/generated/folder1/file1.ts",
@@ -51,7 +53,8 @@ Resolution:: {
   "resolvedModule": {
     "resolvedFileName": "/root/folder1/file1_1/index.d.ts",
     "extension": ".d.ts",
-    "isExternalLibraryImport": false
+    "isExternalLibraryImport": false,
+    "resolvedUsingTsExtension": false
   },
   "failedLookupLocations": [
     "/root/generated/folder1/file1_1.ts",
@@ -87,7 +90,8 @@ Resolution:: {
   "resolvedModule": {
     "resolvedFileName": "/root/generated/folder1/file2.ts",
     "extension": ".ts",
-    "isExternalLibraryImport": false
+    "isExternalLibraryImport": false,
+    "resolvedUsingTsExtension": false
   },
   "failedLookupLocations": [
     "/root/folder1/file2.ts",
@@ -105,7 +109,8 @@ Resolution:: {
   "resolvedModule": {
     "resolvedFileName": "/root/folder1/file1.ts",
     "extension": ".ts",
-    "isExternalLibraryImport": false
+    "isExternalLibraryImport": false,
+    "resolvedUsingTsExtension": false
   },
   "failedLookupLocations": [
     "/root/generated/folder1/file1.ts",
@@ -123,7 +128,8 @@ Resolution:: {
   "resolvedModule": {
     "resolvedFileName": "/root/folder1/file1_1/index.d.ts",
     "extension": ".d.ts",
-    "isExternalLibraryImport": false
+    "isExternalLibraryImport": false,
+    "resolvedUsingTsExtension": false
   },
   "failedLookupLocations": [
     "/root/generated/folder1/file1_1.ts",
diff --git a/tests/baselines/reference/moduleResolution/non-relative-module-name-as-directory.js b/tests/baselines/reference/moduleResolution/non-relative-module-name-as-directory.js
index 14229a28387a9..f631d3c016e7b 100644
--- a/tests/baselines/reference/moduleResolution/non-relative-module-name-as-directory.js
+++ b/tests/baselines/reference/moduleResolution/non-relative-module-name-as-directory.js
@@ -9,7 +9,8 @@ Resolution:: {
   "resolvedModule": {
     "resolvedFileName": "/a/node_modules/foo/index.d.ts",
     "extension": ".d.ts",
-    "isExternalLibraryImport": true
+    "isExternalLibraryImport": true,
+    "resolvedUsingTsExtension": false
   },
   "failedLookupLocations": [
     "/a/node_modules/b/c/node_modules/d/node_modules/foo/package.json",
@@ -62,7 +63,8 @@ Resolution:: {
   "resolvedModule": {
     "resolvedFileName": "/a/node_modules/foo/index.d.ts",
     "extension": ".d.ts",
-    "isExternalLibraryImport": true
+    "isExternalLibraryImport": true,
+    "resolvedUsingTsExtension": false
   },
   "failedLookupLocations": [
     "/a/node_modules/b/c/node_modules/d/node_modules/foo/package.json",
diff --git a/tests/baselines/reference/moduleResolution/non-relative-module-name-as-file-ts-files-not-loaded.js b/tests/baselines/reference/moduleResolution/non-relative-module-name-as-file-ts-files-not-loaded.js
index 9fc065864bbdd..b30a6b150a505 100644
--- a/tests/baselines/reference/moduleResolution/non-relative-module-name-as-file-ts-files-not-loaded.js
+++ b/tests/baselines/reference/moduleResolution/non-relative-module-name-as-file-ts-files-not-loaded.js
@@ -9,7 +9,8 @@ Resolution:: {
   "resolvedModule": {
     "resolvedFileName": "/a/b/node_modules/foo.ts",
     "extension": ".ts",
-    "isExternalLibraryImport": true
+    "isExternalLibraryImport": true,
+    "resolvedUsingTsExtension": false
   },
   "failedLookupLocations": [
     "/a/b/c/d/node_modules/foo/package.json",
@@ -47,7 +48,8 @@ Resolution:: {
   "resolvedModule": {
     "resolvedFileName": "/a/b/node_modules/foo.ts",
     "extension": ".ts",
-    "isExternalLibraryImport": true
+    "isExternalLibraryImport": true,
+    "resolvedUsingTsExtension": false
   },
   "failedLookupLocations": [
     "/a/b/c/d/node_modules/foo/package.json",
diff --git a/tests/baselines/reference/moduleResolution/non-relative-module-name-as-file.js b/tests/baselines/reference/moduleResolution/non-relative-module-name-as-file.js
index 48bf3770870e9..4ba986ae2ecf4 100644
--- a/tests/baselines/reference/moduleResolution/non-relative-module-name-as-file.js
+++ b/tests/baselines/reference/moduleResolution/non-relative-module-name-as-file.js
@@ -9,7 +9,8 @@ Resolution:: {
   "resolvedModule": {
     "resolvedFileName": "/a/b/node_modules/foo.d.ts",
     "extension": ".d.ts",
-    "isExternalLibraryImport": true
+    "isExternalLibraryImport": true,
+    "resolvedUsingTsExtension": false
   },
   "failedLookupLocations": [
     "/a/b/c/d/node_modules/foo/package.json",
@@ -49,7 +50,8 @@ Resolution:: {
   "resolvedModule": {
     "resolvedFileName": "/a/b/node_modules/foo.d.ts",
     "extension": ".d.ts",
-    "isExternalLibraryImport": true
+    "isExternalLibraryImport": true,
+    "resolvedUsingTsExtension": false
   },
   "failedLookupLocations": [
     "/a/b/c/d/node_modules/foo/package.json",
diff --git a/tests/baselines/reference/moduleResolution/non-relative-preserveSymlinks.js b/tests/baselines/reference/moduleResolution/non-relative-preserveSymlinks.js
index 5668982afcc90..b5f9ceb12e06c 100644
--- a/tests/baselines/reference/moduleResolution/non-relative-preserveSymlinks.js
+++ b/tests/baselines/reference/moduleResolution/non-relative-preserveSymlinks.js
@@ -12,7 +12,8 @@ Resolution:: {
     "resolvedFileName": "/linked/index.d.ts",
     "originalPath": "/app/node_modules/linked/index.d.ts",
     "extension": ".d.ts",
-    "isExternalLibraryImport": true
+    "isExternalLibraryImport": true,
+    "resolvedUsingTsExtension": false
   },
   "failedLookupLocations": [
     "/app/node_modules/linked.ts",
@@ -40,7 +41,8 @@ Resolution:: {
   "resolvedModule": {
     "resolvedFileName": "/app/node_modules/linked/index.d.ts",
     "extension": ".d.ts",
-    "isExternalLibraryImport": true
+    "isExternalLibraryImport": true,
+    "resolvedUsingTsExtension": false
   },
   "failedLookupLocations": [
     "/app/node_modules/linked.ts",
diff --git a/tests/baselines/reference/moduleResolution/non-relative-preserves-originalPath-on-cache-hit.js b/tests/baselines/reference/moduleResolution/non-relative-preserves-originalPath-on-cache-hit.js
index 5ed2351fe0247..50b20f9a56ff5 100644
--- a/tests/baselines/reference/moduleResolution/non-relative-preserves-originalPath-on-cache-hit.js
+++ b/tests/baselines/reference/moduleResolution/non-relative-preserves-originalPath-on-cache-hit.js
@@ -12,7 +12,8 @@ Resolution:: {
     "resolvedFileName": "/linked/index.d.ts",
     "originalPath": "/app/node_modules/linked/index.d.ts",
     "extension": ".d.ts",
-    "isExternalLibraryImport": true
+    "isExternalLibraryImport": true,
+    "resolvedUsingTsExtension": false
   },
   "failedLookupLocations": [
     "/app/src/node_modules/linked/package.json",
@@ -43,7 +44,8 @@ Resolution:: {
     "resolvedFileName": "/linked/index.d.ts",
     "originalPath": "/app/node_modules/linked/index.d.ts",
     "extension": ".d.ts",
-    "isExternalLibraryImport": true
+    "isExternalLibraryImport": true,
+    "resolvedUsingTsExtension": false
   },
   "failedLookupLocations": [
     "/app/src/node_modules/linked/package.json",
diff --git a/tests/baselines/reference/moduleResolution/non-relative-uses-originalPath-for-caching.js b/tests/baselines/reference/moduleResolution/non-relative-uses-originalPath-for-caching.js
index dcc6faae386ea..5508c607f5330 100644
--- a/tests/baselines/reference/moduleResolution/non-relative-uses-originalPath-for-caching.js
+++ b/tests/baselines/reference/moduleResolution/non-relative-uses-originalPath-for-caching.js
@@ -12,7 +12,8 @@ Resolution:: {
     "resolvedFileName": "/modules/a.ts",
     "originalPath": "/sub/node_modules/a/index.ts",
     "extension": ".ts",
-    "isExternalLibraryImport": true
+    "isExternalLibraryImport": true,
+    "resolvedUsingTsExtension": false
   },
   "failedLookupLocations": [
     "/sub/dir/node_modules/a/package.json",
@@ -41,7 +42,8 @@ Resolution:: {
     "resolvedFileName": "/modules/a.ts",
     "originalPath": "/sub/node_modules/a/index.ts",
     "extension": ".ts",
-    "isExternalLibraryImport": true
+    "isExternalLibraryImport": true,
+    "resolvedUsingTsExtension": false
   },
   "failedLookupLocations": [
     "/sub/dir/node_modules/a/package.json",
diff --git a/tests/baselines/reference/moduleResolution/relative-module-name-as-directory-load-index.js b/tests/baselines/reference/moduleResolution/relative-module-name-as-directory-load-index.js
index d13fa757ba9d3..94c2f091ad177 100644
--- a/tests/baselines/reference/moduleResolution/relative-module-name-as-directory-load-index.js
+++ b/tests/baselines/reference/moduleResolution/relative-module-name-as-directory-load-index.js
@@ -12,7 +12,8 @@ Resolution:: {
   "resolvedModule": {
     "resolvedFileName": "/a/b/foo/index.d.ts",
     "extension": ".d.ts",
-    "isExternalLibraryImport": false
+    "isExternalLibraryImport": false,
+    "resolvedUsingTsExtension": false
   },
   "failedLookupLocations": [
     "/a/b/foo.ts",
@@ -47,7 +48,8 @@ Resolution:: {
   "resolvedModule": {
     "resolvedFileName": "/a/b/foo/index.d.ts",
     "extension": ".d.ts",
-    "isExternalLibraryImport": false
+    "isExternalLibraryImport": false,
+    "resolvedUsingTsExtension": false
   },
   "failedLookupLocations": [
     "/a/b/foo.ts",
diff --git a/tests/baselines/reference/moduleResolution/relative-module-name-as-directory-with-invalid-typings.js b/tests/baselines/reference/moduleResolution/relative-module-name-as-directory-with-invalid-typings.js
index f23570eb03585..9e5149dce238b 100644
--- a/tests/baselines/reference/moduleResolution/relative-module-name-as-directory-with-invalid-typings.js
+++ b/tests/baselines/reference/moduleResolution/relative-module-name-as-directory-with-invalid-typings.js
@@ -15,7 +15,8 @@ Resolution:: {
   "resolvedModule": {
     "resolvedFileName": "/node_modules/b/index.d.ts",
     "extension": ".d.ts",
-    "isExternalLibraryImport": true
+    "isExternalLibraryImport": true,
+    "resolvedUsingTsExtension": false
   },
   "failedLookupLocations": [
     "/a/node_modules/b/package.json",
@@ -56,7 +57,8 @@ Resolution:: {
   "resolvedModule": {
     "resolvedFileName": "/node_modules/b/index.d.ts",
     "extension": ".d.ts",
-    "isExternalLibraryImport": true
+    "isExternalLibraryImport": true,
+    "resolvedUsingTsExtension": false
   },
   "failedLookupLocations": [
     "/a/node_modules/b/package.json",
@@ -97,7 +99,8 @@ Resolution:: {
   "resolvedModule": {
     "resolvedFileName": "/node_modules/b/index.d.ts",
     "extension": ".d.ts",
-    "isExternalLibraryImport": true
+    "isExternalLibraryImport": true,
+    "resolvedUsingTsExtension": false
   },
   "failedLookupLocations": [
     "/a/node_modules/b/package.json",
@@ -138,7 +141,8 @@ Resolution:: {
   "resolvedModule": {
     "resolvedFileName": "/node_modules/b/index.d.ts",
     "extension": ".d.ts",
-    "isExternalLibraryImport": true
+    "isExternalLibraryImport": true,
+    "resolvedUsingTsExtension": false
   },
   "failedLookupLocations": [
     "/a/node_modules/b/package.json",
@@ -179,7 +183,8 @@ Resolution:: {
   "resolvedModule": {
     "resolvedFileName": "/node_modules/b/index.d.ts",
     "extension": ".d.ts",
-    "isExternalLibraryImport": true
+    "isExternalLibraryImport": true,
+    "resolvedUsingTsExtension": false
   },
   "failedLookupLocations": [
     "/a/node_modules/b/package.json",
@@ -220,7 +225,8 @@ Resolution:: {
   "resolvedModule": {
     "resolvedFileName": "/node_modules/b/index.d.ts",
     "extension": ".d.ts",
-    "isExternalLibraryImport": true
+    "isExternalLibraryImport": true,
+    "resolvedUsingTsExtension": false
   },
   "failedLookupLocations": [
     "/a/node_modules/b/package.json",
@@ -261,7 +267,8 @@ Resolution:: {
   "resolvedModule": {
     "resolvedFileName": "/node_modules/b/index.d.ts",
     "extension": ".d.ts",
-    "isExternalLibraryImport": true
+    "isExternalLibraryImport": true,
+    "resolvedUsingTsExtension": false
   },
   "failedLookupLocations": [
     "/a/node_modules/b/package.json",
@@ -302,7 +309,8 @@ Resolution:: {
   "resolvedModule": {
     "resolvedFileName": "/node_modules/b/index.d.ts",
     "extension": ".d.ts",
-    "isExternalLibraryImport": true
+    "isExternalLibraryImport": true,
+    "resolvedUsingTsExtension": false
   },
   "failedLookupLocations": [
     "/a/node_modules/b/package.json",
@@ -343,7 +351,8 @@ Resolution:: {
   "resolvedModule": {
     "resolvedFileName": "/node_modules/b/index.d.ts",
     "extension": ".d.ts",
-    "isExternalLibraryImport": true
+    "isExternalLibraryImport": true,
+    "resolvedUsingTsExtension": false
   },
   "failedLookupLocations": [
     "/a/node_modules/b/package.json",
@@ -384,7 +393,8 @@ Resolution:: {
   "resolvedModule": {
     "resolvedFileName": "/node_modules/b/index.d.ts",
     "extension": ".d.ts",
-    "isExternalLibraryImport": true
+    "isExternalLibraryImport": true,
+    "resolvedUsingTsExtension": false
   },
   "failedLookupLocations": [
     "/a/node_modules/b/package.json",
diff --git a/tests/baselines/reference/moduleResolution/relative-module-name-as-directory.js b/tests/baselines/reference/moduleResolution/relative-module-name-as-directory.js
index 05cffbff74acc..33180674c0dd2 100644
--- a/tests/baselines/reference/moduleResolution/relative-module-name-as-directory.js
+++ b/tests/baselines/reference/moduleResolution/relative-module-name-as-directory.js
@@ -12,7 +12,8 @@ Resolution:: {
   "resolvedModule": {
     "resolvedFileName": "/a/b/c/bar/c/d/e.d.ts",
     "extension": ".d.ts",
-    "isExternalLibraryImport": false
+    "isExternalLibraryImport": false,
+    "resolvedUsingTsExtension": false
   },
   "failedLookupLocations": [
     "/a/b/c/bar.ts",
@@ -38,7 +39,8 @@ Resolution:: {
   "resolvedModule": {
     "resolvedFileName": "/a/b/c/bar/c/d/e.d.ts",
     "extension": ".d.ts",
-    "isExternalLibraryImport": false
+    "isExternalLibraryImport": false,
+    "resolvedUsingTsExtension": false
   },
   "failedLookupLocations": [
     "/a/b/c/bar.ts",
@@ -64,7 +66,8 @@ Resolution:: {
   "resolvedModule": {
     "resolvedFileName": "/a/bar/e.d.ts",
     "extension": ".d.ts",
-    "isExternalLibraryImport": false
+    "isExternalLibraryImport": false,
+    "resolvedUsingTsExtension": false
   },
   "failedLookupLocations": [
     "/a/bar.ts",
@@ -90,7 +93,8 @@ Resolution:: {
   "resolvedModule": {
     "resolvedFileName": "/a/bar/e.d.ts",
     "extension": ".d.ts",
-    "isExternalLibraryImport": false
+    "isExternalLibraryImport": false,
+    "resolvedUsingTsExtension": false
   },
   "failedLookupLocations": [
     "/a/bar.ts",
@@ -116,7 +120,8 @@ Resolution:: {
   "resolvedModule": {
     "resolvedFileName": "/bar/e.d.ts",
     "extension": ".d.ts",
-    "isExternalLibraryImport": false
+    "isExternalLibraryImport": false,
+    "resolvedUsingTsExtension": false
   },
   "failedLookupLocations": [
     "/bar.ts",
@@ -142,7 +147,8 @@ Resolution:: {
   "resolvedModule": {
     "resolvedFileName": "/bar/e.d.ts",
     "extension": ".d.ts",
-    "isExternalLibraryImport": false
+    "isExternalLibraryImport": false,
+    "resolvedUsingTsExtension": false
   },
   "failedLookupLocations": [
     "/bar.ts",
@@ -168,7 +174,8 @@ Resolution:: {
   "resolvedModule": {
     "resolvedFileName": "c:/bar/e.d.ts",
     "extension": ".d.ts",
-    "isExternalLibraryImport": false
+    "isExternalLibraryImport": false,
+    "resolvedUsingTsExtension": false
   },
   "failedLookupLocations": [
     "c:/bar.ts",
@@ -194,7 +201,8 @@ Resolution:: {
   "resolvedModule": {
     "resolvedFileName": "c:/bar/e.d.ts",
     "extension": ".d.ts",
-    "isExternalLibraryImport": false
+    "isExternalLibraryImport": false,
+    "resolvedUsingTsExtension": false
   },
   "failedLookupLocations": [
     "c:/bar.ts",
diff --git a/tests/baselines/reference/moduleResolution/relative-module-name-as-file.js b/tests/baselines/reference/moduleResolution/relative-module-name-as-file.js
index a64b27f5761df..79b37762a7635 100644
--- a/tests/baselines/reference/moduleResolution/relative-module-name-as-file.js
+++ b/tests/baselines/reference/moduleResolution/relative-module-name-as-file.js
@@ -10,7 +10,8 @@ Resolution:: {
   "resolvedModule": {
     "resolvedFileName": "/foo/bar/foo.ts",
     "extension": ".ts",
-    "isExternalLibraryImport": false
+    "isExternalLibraryImport": false,
+    "resolvedUsingTsExtension": false
   }
 }
 
@@ -25,7 +26,8 @@ Resolution:: {
   "resolvedModule": {
     "resolvedFileName": "/foo/bar/foo.ts",
     "extension": ".ts",
-    "isExternalLibraryImport": false
+    "isExternalLibraryImport": false,
+    "resolvedUsingTsExtension": false
   }
 }
 
@@ -40,7 +42,8 @@ Resolution:: {
   "resolvedModule": {
     "resolvedFileName": "/foo/bar/foo.tsx",
     "extension": ".tsx",
-    "isExternalLibraryImport": false
+    "isExternalLibraryImport": false,
+    "resolvedUsingTsExtension": false
   },
   "failedLookupLocations": [
     "/foo/bar/foo.ts"
@@ -58,7 +61,8 @@ Resolution:: {
   "resolvedModule": {
     "resolvedFileName": "/foo/bar/foo.tsx",
     "extension": ".tsx",
-    "isExternalLibraryImport": false
+    "isExternalLibraryImport": false,
+    "resolvedUsingTsExtension": false
   },
   "failedLookupLocations": [
     "/foo/bar/foo.ts"
@@ -76,7 +80,8 @@ Resolution:: {
   "resolvedModule": {
     "resolvedFileName": "/foo/bar/foo.d.ts",
     "extension": ".d.ts",
-    "isExternalLibraryImport": false
+    "isExternalLibraryImport": false,
+    "resolvedUsingTsExtension": false
   },
   "failedLookupLocations": [
     "/foo/bar/foo.ts",
@@ -95,7 +100,8 @@ Resolution:: {
   "resolvedModule": {
     "resolvedFileName": "/foo/bar/foo.d.ts",
     "extension": ".d.ts",
-    "isExternalLibraryImport": false
+    "isExternalLibraryImport": false,
+    "resolvedUsingTsExtension": false
   },
   "failedLookupLocations": [
     "/foo/bar/foo.ts",
@@ -116,7 +122,8 @@ Resolution:: {
   "resolvedModule": {
     "resolvedFileName": "/foo/foo.ts",
     "extension": ".ts",
-    "isExternalLibraryImport": false
+    "isExternalLibraryImport": false,
+    "resolvedUsingTsExtension": false
   }
 }
 
@@ -131,7 +138,8 @@ Resolution:: {
   "resolvedModule": {
     "resolvedFileName": "/foo/foo.ts",
     "extension": ".ts",
-    "isExternalLibraryImport": false
+    "isExternalLibraryImport": false,
+    "resolvedUsingTsExtension": false
   }
 }
 
@@ -146,7 +154,8 @@ Resolution:: {
   "resolvedModule": {
     "resolvedFileName": "/foo/foo.tsx",
     "extension": ".tsx",
-    "isExternalLibraryImport": false
+    "isExternalLibraryImport": false,
+    "resolvedUsingTsExtension": false
   },
   "failedLookupLocations": [
     "/foo/foo.ts"
@@ -164,7 +173,8 @@ Resolution:: {
   "resolvedModule": {
     "resolvedFileName": "/foo/foo.tsx",
     "extension": ".tsx",
-    "isExternalLibraryImport": false
+    "isExternalLibraryImport": false,
+    "resolvedUsingTsExtension": false
   },
   "failedLookupLocations": [
     "/foo/foo.ts"
@@ -182,7 +192,8 @@ Resolution:: {
   "resolvedModule": {
     "resolvedFileName": "/foo/foo.d.ts",
     "extension": ".d.ts",
-    "isExternalLibraryImport": false
+    "isExternalLibraryImport": false,
+    "resolvedUsingTsExtension": false
   },
   "failedLookupLocations": [
     "/foo/foo.ts",
@@ -201,7 +212,8 @@ Resolution:: {
   "resolvedModule": {
     "resolvedFileName": "/foo/foo.d.ts",
     "extension": ".d.ts",
-    "isExternalLibraryImport": false
+    "isExternalLibraryImport": false,
+    "resolvedUsingTsExtension": false
   },
   "failedLookupLocations": [
     "/foo/foo.ts",
@@ -222,7 +234,8 @@ Resolution:: {
   "resolvedModule": {
     "resolvedFileName": "/foo.ts",
     "extension": ".ts",
-    "isExternalLibraryImport": false
+    "isExternalLibraryImport": false,
+    "resolvedUsingTsExtension": false
   }
 }
 
@@ -237,7 +250,8 @@ Resolution:: {
   "resolvedModule": {
     "resolvedFileName": "/foo.ts",
     "extension": ".ts",
-    "isExternalLibraryImport": false
+    "isExternalLibraryImport": false,
+    "resolvedUsingTsExtension": false
   }
 }
 
@@ -252,7 +266,8 @@ Resolution:: {
   "resolvedModule": {
     "resolvedFileName": "/foo.tsx",
     "extension": ".tsx",
-    "isExternalLibraryImport": false
+    "isExternalLibraryImport": false,
+    "resolvedUsingTsExtension": false
   },
   "failedLookupLocations": [
     "/foo.ts"
@@ -270,7 +285,8 @@ Resolution:: {
   "resolvedModule": {
     "resolvedFileName": "/foo.tsx",
     "extension": ".tsx",
-    "isExternalLibraryImport": false
+    "isExternalLibraryImport": false,
+    "resolvedUsingTsExtension": false
   },
   "failedLookupLocations": [
     "/foo.ts"
@@ -288,7 +304,8 @@ Resolution:: {
   "resolvedModule": {
     "resolvedFileName": "/foo.d.ts",
     "extension": ".d.ts",
-    "isExternalLibraryImport": false
+    "isExternalLibraryImport": false,
+    "resolvedUsingTsExtension": false
   },
   "failedLookupLocations": [
     "/foo.ts",
@@ -307,7 +324,8 @@ Resolution:: {
   "resolvedModule": {
     "resolvedFileName": "/foo.d.ts",
     "extension": ".d.ts",
-    "isExternalLibraryImport": false
+    "isExternalLibraryImport": false,
+    "resolvedUsingTsExtension": false
   },
   "failedLookupLocations": [
     "/foo.ts",
@@ -328,7 +346,8 @@ Resolution:: {
   "resolvedModule": {
     "resolvedFileName": "c:/foo.ts",
     "extension": ".ts",
-    "isExternalLibraryImport": false
+    "isExternalLibraryImport": false,
+    "resolvedUsingTsExtension": false
   }
 }
 
@@ -343,7 +362,8 @@ Resolution:: {
   "resolvedModule": {
     "resolvedFileName": "c:/foo.ts",
     "extension": ".ts",
-    "isExternalLibraryImport": false
+    "isExternalLibraryImport": false,
+    "resolvedUsingTsExtension": false
   }
 }
 
@@ -358,7 +378,8 @@ Resolution:: {
   "resolvedModule": {
     "resolvedFileName": "c:/foo.tsx",
     "extension": ".tsx",
-    "isExternalLibraryImport": false
+    "isExternalLibraryImport": false,
+    "resolvedUsingTsExtension": false
   },
   "failedLookupLocations": [
     "c:/foo.ts"
@@ -376,7 +397,8 @@ Resolution:: {
   "resolvedModule": {
     "resolvedFileName": "c:/foo.tsx",
     "extension": ".tsx",
-    "isExternalLibraryImport": false
+    "isExternalLibraryImport": false,
+    "resolvedUsingTsExtension": false
   },
   "failedLookupLocations": [
     "c:/foo.ts"
@@ -394,7 +416,8 @@ Resolution:: {
   "resolvedModule": {
     "resolvedFileName": "c:/foo.d.ts",
     "extension": ".d.ts",
-    "isExternalLibraryImport": false
+    "isExternalLibraryImport": false,
+    "resolvedUsingTsExtension": false
   },
   "failedLookupLocations": [
     "c:/foo.ts",
@@ -413,7 +436,8 @@ Resolution:: {
   "resolvedModule": {
     "resolvedFileName": "c:/foo.d.ts",
     "extension": ".d.ts",
-    "isExternalLibraryImport": false
+    "isExternalLibraryImport": false,
+    "resolvedUsingTsExtension": false
   },
   "failedLookupLocations": [
     "c:/foo.ts",
diff --git a/tests/baselines/reference/packageJsonImportsExportsOptionCompat(moduleresolution=classic).errors.txt b/tests/baselines/reference/packageJsonImportsExportsOptionCompat(moduleresolution=classic).errors.txt
new file mode 100644
index 0000000000000..93ffdb73d1766
--- /dev/null
+++ b/tests/baselines/reference/packageJsonImportsExportsOptionCompat(moduleresolution=classic).errors.txt
@@ -0,0 +1,8 @@
+error TS5098: Option 'resolvePackageJsonExports' can only be used when 'moduleResolution' is set to 'node16', 'nodenext', or 'bundler'.
+error TS5098: Option 'resolvePackageJsonImports' can only be used when 'moduleResolution' is set to 'node16', 'nodenext', or 'bundler'.
+
+
+!!! error TS5098: Option 'resolvePackageJsonExports' can only be used when 'moduleResolution' is set to 'node16', 'nodenext', or 'bundler'.
+!!! error TS5098: Option 'resolvePackageJsonImports' can only be used when 'moduleResolution' is set to 'node16', 'nodenext', or 'bundler'.
+==== tests/cases/conformance/moduleResolution/index.ts (0 errors) ====
+    
\ No newline at end of file
diff --git a/tests/baselines/reference/packageJsonImportsExportsOptionCompat(moduleresolution=node).errors.txt b/tests/baselines/reference/packageJsonImportsExportsOptionCompat(moduleresolution=node).errors.txt
new file mode 100644
index 0000000000000..93ffdb73d1766
--- /dev/null
+++ b/tests/baselines/reference/packageJsonImportsExportsOptionCompat(moduleresolution=node).errors.txt
@@ -0,0 +1,8 @@
+error TS5098: Option 'resolvePackageJsonExports' can only be used when 'moduleResolution' is set to 'node16', 'nodenext', or 'bundler'.
+error TS5098: Option 'resolvePackageJsonImports' can only be used when 'moduleResolution' is set to 'node16', 'nodenext', or 'bundler'.
+
+
+!!! error TS5098: Option 'resolvePackageJsonExports' can only be used when 'moduleResolution' is set to 'node16', 'nodenext', or 'bundler'.
+!!! error TS5098: Option 'resolvePackageJsonImports' can only be used when 'moduleResolution' is set to 'node16', 'nodenext', or 'bundler'.
+==== tests/cases/conformance/moduleResolution/index.ts (0 errors) ====
+    
\ No newline at end of file
diff --git a/tests/baselines/reference/reuseProgramStructure/can-reuse-module-resolutions-from-non-modified-files.js b/tests/baselines/reference/reuseProgramStructure/can-reuse-module-resolutions-from-non-modified-files.js
index 83f3d24b636ae..0bbadac80d050 100644
--- a/tests/baselines/reference/reuseProgramStructure/can-reuse-module-resolutions-from-non-modified-files.js
+++ b/tests/baselines/reference/reuseProgramStructure/can-reuse-module-resolutions-from-non-modified-files.js
@@ -53,7 +53,8 @@ resolvedModules:
   "resolvedModule": {
     "resolvedFileName": "b1.ts",
     "extension": ".ts",
-    "isExternalLibraryImport": false
+    "isExternalLibraryImport": false,
+    "resolvedUsingTsExtension": false
   }
 }
 resolvedTypeReferenceDirectiveNames: 
@@ -79,14 +80,16 @@ resolvedModules:
   "resolvedModule": {
     "resolvedFileName": "b2.ts",
     "extension": ".ts",
-    "isExternalLibraryImport": false
+    "isExternalLibraryImport": false,
+    "resolvedUsingTsExtension": false
   }
 }
 ./f1: {
   "resolvedModule": {
     "resolvedFileName": "f1.ts",
     "extension": ".ts",
-    "isExternalLibraryImport": false
+    "isExternalLibraryImport": false,
+    "resolvedUsingTsExtension": false
   }
 }
 resolvedTypeReferenceDirectiveNames: 
@@ -187,7 +190,8 @@ resolvedModules:
   "resolvedModule": {
     "resolvedFileName": "b1.ts",
     "extension": ".ts",
-    "isExternalLibraryImport": false
+    "isExternalLibraryImport": false,
+    "resolvedUsingTsExtension": false
   }
 }
 resolvedTypeReferenceDirectiveNames: 
@@ -213,14 +217,16 @@ resolvedModules:
   "resolvedModule": {
     "resolvedFileName": "b2.ts",
     "extension": ".ts",
-    "isExternalLibraryImport": false
+    "isExternalLibraryImport": false,
+    "resolvedUsingTsExtension": false
   }
 }
 ./f1: {
   "resolvedModule": {
     "resolvedFileName": "f1.ts",
     "extension": ".ts",
-    "isExternalLibraryImport": false
+    "isExternalLibraryImport": false,
+    "resolvedUsingTsExtension": false
   }
 }
 resolvedTypeReferenceDirectiveNames: 
@@ -310,7 +316,8 @@ resolvedModules:
   "resolvedModule": {
     "resolvedFileName": "b1.ts",
     "extension": ".ts",
-    "isExternalLibraryImport": false
+    "isExternalLibraryImport": false,
+    "resolvedUsingTsExtension": false
   }
 }
 resolvedTypeReferenceDirectiveNames: undefined
@@ -326,14 +333,16 @@ resolvedModules:
   "resolvedModule": {
     "resolvedFileName": "b2.ts",
     "extension": ".ts",
-    "isExternalLibraryImport": false
+    "isExternalLibraryImport": false,
+    "resolvedUsingTsExtension": false
   }
 }
 ./f1: {
   "resolvedModule": {
     "resolvedFileName": "f1.ts",
     "extension": ".ts",
-    "isExternalLibraryImport": false
+    "isExternalLibraryImport": false,
+    "resolvedUsingTsExtension": false
   }
 }
 resolvedTypeReferenceDirectiveNames: 
@@ -418,7 +427,8 @@ resolvedModules:
   "resolvedModule": {
     "resolvedFileName": "b1.ts",
     "extension": ".ts",
-    "isExternalLibraryImport": false
+    "isExternalLibraryImport": false,
+    "resolvedUsingTsExtension": false
   }
 }
 resolvedTypeReferenceDirectiveNames: undefined
@@ -434,14 +444,16 @@ resolvedModules:
   "resolvedModule": {
     "resolvedFileName": "b2.ts",
     "extension": ".ts",
-    "isExternalLibraryImport": false
+    "isExternalLibraryImport": false,
+    "resolvedUsingTsExtension": false
   }
 }
 ./f1: {
   "resolvedModule": {
     "resolvedFileName": "f1.ts",
     "extension": ".ts",
-    "isExternalLibraryImport": false
+    "isExternalLibraryImport": false,
+    "resolvedUsingTsExtension": false
   }
 }
 resolvedTypeReferenceDirectiveNames: 
@@ -525,7 +537,8 @@ resolvedModules:
   "resolvedModule": {
     "resolvedFileName": "b1.ts",
     "extension": ".ts",
-    "isExternalLibraryImport": false
+    "isExternalLibraryImport": false,
+    "resolvedUsingTsExtension": false
   }
 }
 resolvedTypeReferenceDirectiveNames: undefined
@@ -541,14 +554,16 @@ resolvedModules:
   "resolvedModule": {
     "resolvedFileName": "b2.ts",
     "extension": ".ts",
-    "isExternalLibraryImport": false
+    "isExternalLibraryImport": false,
+    "resolvedUsingTsExtension": false
   }
 }
 ./f1: {
   "resolvedModule": {
     "resolvedFileName": "f1.ts",
     "extension": ".ts",
-    "isExternalLibraryImport": false
+    "isExternalLibraryImport": false,
+    "resolvedUsingTsExtension": false
   }
 }
 resolvedTypeReferenceDirectiveNames: 
@@ -630,7 +645,8 @@ resolvedModules:
   "resolvedModule": {
     "resolvedFileName": "b1.ts",
     "extension": ".ts",
-    "isExternalLibraryImport": false
+    "isExternalLibraryImport": false,
+    "resolvedUsingTsExtension": false
   }
 }
 resolvedTypeReferenceDirectiveNames: undefined
@@ -646,14 +662,16 @@ resolvedModules:
   "resolvedModule": {
     "resolvedFileName": "b2.ts",
     "extension": ".ts",
-    "isExternalLibraryImport": false
+    "isExternalLibraryImport": false,
+    "resolvedUsingTsExtension": false
   }
 }
 ./f1: {
   "resolvedModule": {
     "resolvedFileName": "f1.ts",
     "extension": ".ts",
-    "isExternalLibraryImport": false
+    "isExternalLibraryImport": false,
+    "resolvedUsingTsExtension": false
   }
 }
 resolvedTypeReferenceDirectiveNames: 
@@ -747,14 +765,16 @@ resolvedModules:
   "resolvedModule": {
     "resolvedFileName": "b2.ts",
     "extension": ".ts",
-    "isExternalLibraryImport": false
+    "isExternalLibraryImport": false,
+    "resolvedUsingTsExtension": false
   }
 }
 ./f1: {
   "resolvedModule": {
     "resolvedFileName": "f1.ts",
     "extension": ".ts",
-    "isExternalLibraryImport": false
+    "isExternalLibraryImport": false,
+    "resolvedUsingTsExtension": false
   }
 }
 resolvedTypeReferenceDirectiveNames: 
diff --git a/tests/baselines/reference/reuseProgramStructure/change-affects-a-single-module-of-a-package.js b/tests/baselines/reference/reuseProgramStructure/change-affects-a-single-module-of-a-package.js
index 1ab1a4b919ced..a6ec1e0691cbd 100644
--- a/tests/baselines/reference/reuseProgramStructure/change-affects-a-single-module-of-a-package.js
+++ b/tests/baselines/reference/reuseProgramStructure/change-affects-a-single-module-of-a-package.js
@@ -20,7 +20,8 @@ resolvedModules:
       "name": "b",
       "subModuleName": "internal.d.ts",
       "version": "1.2.3"
-    }
+    },
+    "resolvedUsingTsExtension": false
   },
   "failedLookupLocations": [
     "/node_modules/b/internal.ts",
@@ -46,7 +47,8 @@ b: {
       "name": "b",
       "subModuleName": "index.d.ts",
       "version": "1.2.3"
-    }
+    },
+    "resolvedUsingTsExtension": false
   },
   "failedLookupLocations": [
     "/node_modules/b.ts",
@@ -89,7 +91,8 @@ resolvedModules:
       "name": "b",
       "subModuleName": "internal.d.ts",
       "version": "1.2.3"
-    }
+    },
+    "resolvedUsingTsExtension": false
   },
   "failedLookupLocations": [
     "/node_modules/b/internal.ts",
@@ -115,7 +118,8 @@ b: {
       "name": "b",
       "subModuleName": "index.d.ts",
       "version": "1.2.3"
-    }
+    },
+    "resolvedUsingTsExtension": false
   },
   "failedLookupLocations": [
     "/node_modules/b.ts",
diff --git a/tests/baselines/reference/reuseProgramStructure/change-affects-imports.js b/tests/baselines/reference/reuseProgramStructure/change-affects-imports.js
index edc9d673707b4..b1af4711871a3 100644
--- a/tests/baselines/reference/reuseProgramStructure/change-affects-imports.js
+++ b/tests/baselines/reference/reuseProgramStructure/change-affects-imports.js
@@ -54,7 +54,8 @@ b: {
   "resolvedModule": {
     "resolvedFileName": "b.ts",
     "extension": ".ts",
-    "isExternalLibraryImport": false
+    "isExternalLibraryImport": false,
+    "resolvedUsingTsExtension": false
   }
 }
 resolvedTypeReferenceDirectiveNames: undefined
diff --git a/tests/baselines/reference/reuseProgramStructure/fetches-imports-after-npm-install.js b/tests/baselines/reference/reuseProgramStructure/fetches-imports-after-npm-install.js
index 271483c51fddc..1c4e39c7c86ba 100644
--- a/tests/baselines/reference/reuseProgramStructure/fetches-imports-after-npm-install.js
+++ b/tests/baselines/reference/reuseProgramStructure/fetches-imports-after-npm-install.js
@@ -76,7 +76,8 @@ a: {
   "resolvedModule": {
     "resolvedFileName": "node_modules/a/index.d.ts",
     "extension": ".d.ts",
-    "isExternalLibraryImport": true
+    "isExternalLibraryImport": true,
+    "resolvedUsingTsExtension": false
   },
   "failedLookupLocations": [
     "node_modules/a/package.json",
diff --git a/tests/baselines/reference/reuseProgramStructure/redirect-no-change.js b/tests/baselines/reference/reuseProgramStructure/redirect-no-change.js
index edd5b77800c85..d6851e614b653 100644
--- a/tests/baselines/reference/reuseProgramStructure/redirect-no-change.js
+++ b/tests/baselines/reference/reuseProgramStructure/redirect-no-change.js
@@ -20,7 +20,8 @@ x: {
       "name": "x",
       "subModuleName": "index.d.ts",
       "version": "1.2.3"
-    }
+    },
+    "resolvedUsingTsExtension": false
   },
   "failedLookupLocations": [
     "/node_modules/a/node_modules/x.ts",
@@ -56,7 +57,8 @@ x: {
       "name": "x",
       "subModuleName": "index.d.ts",
       "version": "1.2.3"
-    }
+    },
+    "resolvedUsingTsExtension": false
   },
   "failedLookupLocations": [
     "/node_modules/b/node_modules/x.ts",
@@ -80,7 +82,8 @@ a: {
   "resolvedModule": {
     "resolvedFileName": "/node_modules/a/index.d.ts",
     "extension": ".d.ts",
-    "isExternalLibraryImport": true
+    "isExternalLibraryImport": true,
+    "resolvedUsingTsExtension": false
   },
   "failedLookupLocations": [
     "/node_modules/a/package.json",
@@ -95,7 +98,8 @@ b: {
   "resolvedModule": {
     "resolvedFileName": "/node_modules/b/index.d.ts",
     "extension": ".d.ts",
-    "isExternalLibraryImport": true
+    "isExternalLibraryImport": true,
+    "resolvedUsingTsExtension": false
   },
   "failedLookupLocations": [
     "/node_modules/b/package.json",
@@ -136,7 +140,8 @@ x: {
       "name": "x",
       "subModuleName": "index.d.ts",
       "version": "1.2.3"
-    }
+    },
+    "resolvedUsingTsExtension": false
   },
   "failedLookupLocations": [
     "/node_modules/a/node_modules/x.ts",
@@ -172,7 +177,8 @@ x: {
       "name": "x",
       "subModuleName": "index.d.ts",
       "version": "1.2.3"
-    }
+    },
+    "resolvedUsingTsExtension": false
   },
   "failedLookupLocations": [
     "/node_modules/b/node_modules/x.ts",
@@ -196,7 +202,8 @@ a: {
   "resolvedModule": {
     "resolvedFileName": "/node_modules/a/index.d.ts",
     "extension": ".d.ts",
-    "isExternalLibraryImport": true
+    "isExternalLibraryImport": true,
+    "resolvedUsingTsExtension": false
   },
   "failedLookupLocations": [
     "/node_modules/a/package.json",
@@ -211,7 +218,8 @@ b: {
   "resolvedModule": {
     "resolvedFileName": "/node_modules/b/index.d.ts",
     "extension": ".d.ts",
-    "isExternalLibraryImport": true
+    "isExternalLibraryImport": true,
+    "resolvedUsingTsExtension": false
   },
   "failedLookupLocations": [
     "/node_modules/b/package.json",
diff --git a/tests/baselines/reference/reuseProgramStructure/redirect-previous-duplicate-packages.js b/tests/baselines/reference/reuseProgramStructure/redirect-previous-duplicate-packages.js
index 6af47acec2e56..f7a11625082e9 100644
--- a/tests/baselines/reference/reuseProgramStructure/redirect-previous-duplicate-packages.js
+++ b/tests/baselines/reference/reuseProgramStructure/redirect-previous-duplicate-packages.js
@@ -20,7 +20,8 @@ x: {
       "name": "x",
       "subModuleName": "index.d.ts",
       "version": "1.2.3"
-    }
+    },
+    "resolvedUsingTsExtension": false
   },
   "failedLookupLocations": [
     "/node_modules/a/node_modules/x.ts",
@@ -56,7 +57,8 @@ x: {
       "name": "x",
       "subModuleName": "index.d.ts",
       "version": "1.2.4"
-    }
+    },
+    "resolvedUsingTsExtension": false
   },
   "failedLookupLocations": [
     "/node_modules/b/node_modules/x.ts",
@@ -80,7 +82,8 @@ a: {
   "resolvedModule": {
     "resolvedFileName": "/node_modules/a/index.d.ts",
     "extension": ".d.ts",
-    "isExternalLibraryImport": true
+    "isExternalLibraryImport": true,
+    "resolvedUsingTsExtension": false
   },
   "failedLookupLocations": [
     "/node_modules/a/package.json",
@@ -95,7 +98,8 @@ b: {
   "resolvedModule": {
     "resolvedFileName": "/node_modules/b/index.d.ts",
     "extension": ".d.ts",
-    "isExternalLibraryImport": true
+    "isExternalLibraryImport": true,
+    "resolvedUsingTsExtension": false
   },
   "failedLookupLocations": [
     "/node_modules/b/package.json",
@@ -138,7 +142,8 @@ x: {
       "name": "x",
       "subModuleName": "index.d.ts",
       "version": "1.2.3"
-    }
+    },
+    "resolvedUsingTsExtension": false
   },
   "failedLookupLocations": [
     "/node_modules/a/node_modules/x.ts",
@@ -174,7 +179,8 @@ x: {
       "name": "x",
       "subModuleName": "index.d.ts",
       "version": "1.2.3"
-    }
+    },
+    "resolvedUsingTsExtension": false
   },
   "failedLookupLocations": [
     "/node_modules/b/node_modules/x.ts",
@@ -198,7 +204,8 @@ a: {
   "resolvedModule": {
     "resolvedFileName": "/node_modules/a/index.d.ts",
     "extension": ".d.ts",
-    "isExternalLibraryImport": true
+    "isExternalLibraryImport": true,
+    "resolvedUsingTsExtension": false
   },
   "failedLookupLocations": [
     "/node_modules/a/package.json",
@@ -213,7 +220,8 @@ b: {
   "resolvedModule": {
     "resolvedFileName": "/node_modules/b/index.d.ts",
     "extension": ".d.ts",
-    "isExternalLibraryImport": true
+    "isExternalLibraryImport": true,
+    "resolvedUsingTsExtension": false
   },
   "failedLookupLocations": [
     "/node_modules/b/package.json",
diff --git a/tests/baselines/reference/reuseProgramStructure/redirect-target-changes.js b/tests/baselines/reference/reuseProgramStructure/redirect-target-changes.js
index 4afced0c95b7c..83f61703a58aa 100644
--- a/tests/baselines/reference/reuseProgramStructure/redirect-target-changes.js
+++ b/tests/baselines/reference/reuseProgramStructure/redirect-target-changes.js
@@ -20,7 +20,8 @@ x: {
       "name": "x",
       "subModuleName": "index.d.ts",
       "version": "1.2.3"
-    }
+    },
+    "resolvedUsingTsExtension": false
   },
   "failedLookupLocations": [
     "/node_modules/a/node_modules/x.ts",
@@ -56,7 +57,8 @@ x: {
       "name": "x",
       "subModuleName": "index.d.ts",
       "version": "1.2.3"
-    }
+    },
+    "resolvedUsingTsExtension": false
   },
   "failedLookupLocations": [
     "/node_modules/b/node_modules/x.ts",
@@ -80,7 +82,8 @@ a: {
   "resolvedModule": {
     "resolvedFileName": "/node_modules/a/index.d.ts",
     "extension": ".d.ts",
-    "isExternalLibraryImport": true
+    "isExternalLibraryImport": true,
+    "resolvedUsingTsExtension": false
   },
   "failedLookupLocations": [
     "/node_modules/a/package.json",
@@ -95,7 +98,8 @@ b: {
   "resolvedModule": {
     "resolvedFileName": "/node_modules/b/index.d.ts",
     "extension": ".d.ts",
-    "isExternalLibraryImport": true
+    "isExternalLibraryImport": true,
+    "resolvedUsingTsExtension": false
   },
   "failedLookupLocations": [
     "/node_modules/b/package.json",
@@ -131,7 +135,8 @@ x: {
   "resolvedModule": {
     "resolvedFileName": "/node_modules/a/node_modules/x/index.d.ts",
     "extension": ".d.ts",
-    "isExternalLibraryImport": true
+    "isExternalLibraryImport": true,
+    "resolvedUsingTsExtension": false
   },
   "failedLookupLocations": [
     "/node_modules/a/node_modules/x.ts",
@@ -167,7 +172,8 @@ x: {
       "name": "x",
       "subModuleName": "index.d.ts",
       "version": "1.2.3"
-    }
+    },
+    "resolvedUsingTsExtension": false
   },
   "failedLookupLocations": [
     "/node_modules/b/node_modules/x.ts",
@@ -191,7 +197,8 @@ a: {
   "resolvedModule": {
     "resolvedFileName": "/node_modules/a/index.d.ts",
     "extension": ".d.ts",
-    "isExternalLibraryImport": true
+    "isExternalLibraryImport": true,
+    "resolvedUsingTsExtension": false
   },
   "failedLookupLocations": [
     "/node_modules/a/package.json",
@@ -206,7 +213,8 @@ b: {
   "resolvedModule": {
     "resolvedFileName": "/node_modules/b/index.d.ts",
     "extension": ".d.ts",
-    "isExternalLibraryImport": true
+    "isExternalLibraryImport": true,
+    "resolvedUsingTsExtension": false
   },
   "failedLookupLocations": [
     "/node_modules/b/package.json",
diff --git a/tests/baselines/reference/reuseProgramStructure/redirect-underlying-changes.js b/tests/baselines/reference/reuseProgramStructure/redirect-underlying-changes.js
index f8d4c09bc12a7..b22376b0f96a6 100644
--- a/tests/baselines/reference/reuseProgramStructure/redirect-underlying-changes.js
+++ b/tests/baselines/reference/reuseProgramStructure/redirect-underlying-changes.js
@@ -20,7 +20,8 @@ x: {
       "name": "x",
       "subModuleName": "index.d.ts",
       "version": "1.2.3"
-    }
+    },
+    "resolvedUsingTsExtension": false
   },
   "failedLookupLocations": [
     "/node_modules/a/node_modules/x.ts",
@@ -56,7 +57,8 @@ x: {
       "name": "x",
       "subModuleName": "index.d.ts",
       "version": "1.2.3"
-    }
+    },
+    "resolvedUsingTsExtension": false
   },
   "failedLookupLocations": [
     "/node_modules/b/node_modules/x.ts",
@@ -80,7 +82,8 @@ a: {
   "resolvedModule": {
     "resolvedFileName": "/node_modules/a/index.d.ts",
     "extension": ".d.ts",
-    "isExternalLibraryImport": true
+    "isExternalLibraryImport": true,
+    "resolvedUsingTsExtension": false
   },
   "failedLookupLocations": [
     "/node_modules/a/package.json",
@@ -95,7 +98,8 @@ b: {
   "resolvedModule": {
     "resolvedFileName": "/node_modules/b/index.d.ts",
     "extension": ".d.ts",
-    "isExternalLibraryImport": true
+    "isExternalLibraryImport": true,
+    "resolvedUsingTsExtension": false
   },
   "failedLookupLocations": [
     "/node_modules/b/package.json",
@@ -136,7 +140,8 @@ x: {
       "name": "x",
       "subModuleName": "index.d.ts",
       "version": "1.2.3"
-    }
+    },
+    "resolvedUsingTsExtension": false
   },
   "failedLookupLocations": [
     "/node_modules/a/node_modules/x.ts",
@@ -172,7 +177,8 @@ x: {
       "name": "x",
       "subModuleName": "index.d.ts",
       "version": "1.2.4"
-    }
+    },
+    "resolvedUsingTsExtension": false
   },
   "failedLookupLocations": [
     "/node_modules/b/node_modules/x.ts",
@@ -196,7 +202,8 @@ a: {
   "resolvedModule": {
     "resolvedFileName": "/node_modules/a/index.d.ts",
     "extension": ".d.ts",
-    "isExternalLibraryImport": true
+    "isExternalLibraryImport": true,
+    "resolvedUsingTsExtension": false
   },
   "failedLookupLocations": [
     "/node_modules/a/package.json",
@@ -211,7 +218,8 @@ b: {
   "resolvedModule": {
     "resolvedFileName": "/node_modules/b/index.d.ts",
     "extension": ".d.ts",
-    "isExternalLibraryImport": true
+    "isExternalLibraryImport": true,
+    "resolvedUsingTsExtension": false
   },
   "failedLookupLocations": [
     "/node_modules/b/package.json",
diff --git a/tests/baselines/reference/reuseProgramStructure/redirect-with-getSourceFileByPath-no-change.js b/tests/baselines/reference/reuseProgramStructure/redirect-with-getSourceFileByPath-no-change.js
index edd5b77800c85..d6851e614b653 100644
--- a/tests/baselines/reference/reuseProgramStructure/redirect-with-getSourceFileByPath-no-change.js
+++ b/tests/baselines/reference/reuseProgramStructure/redirect-with-getSourceFileByPath-no-change.js
@@ -20,7 +20,8 @@ x: {
       "name": "x",
       "subModuleName": "index.d.ts",
       "version": "1.2.3"
-    }
+    },
+    "resolvedUsingTsExtension": false
   },
   "failedLookupLocations": [
     "/node_modules/a/node_modules/x.ts",
@@ -56,7 +57,8 @@ x: {
       "name": "x",
       "subModuleName": "index.d.ts",
       "version": "1.2.3"
-    }
+    },
+    "resolvedUsingTsExtension": false
   },
   "failedLookupLocations": [
     "/node_modules/b/node_modules/x.ts",
@@ -80,7 +82,8 @@ a: {
   "resolvedModule": {
     "resolvedFileName": "/node_modules/a/index.d.ts",
     "extension": ".d.ts",
-    "isExternalLibraryImport": true
+    "isExternalLibraryImport": true,
+    "resolvedUsingTsExtension": false
   },
   "failedLookupLocations": [
     "/node_modules/a/package.json",
@@ -95,7 +98,8 @@ b: {
   "resolvedModule": {
     "resolvedFileName": "/node_modules/b/index.d.ts",
     "extension": ".d.ts",
-    "isExternalLibraryImport": true
+    "isExternalLibraryImport": true,
+    "resolvedUsingTsExtension": false
   },
   "failedLookupLocations": [
     "/node_modules/b/package.json",
@@ -136,7 +140,8 @@ x: {
       "name": "x",
       "subModuleName": "index.d.ts",
       "version": "1.2.3"
-    }
+    },
+    "resolvedUsingTsExtension": false
   },
   "failedLookupLocations": [
     "/node_modules/a/node_modules/x.ts",
@@ -172,7 +177,8 @@ x: {
       "name": "x",
       "subModuleName": "index.d.ts",
       "version": "1.2.3"
-    }
+    },
+    "resolvedUsingTsExtension": false
   },
   "failedLookupLocations": [
     "/node_modules/b/node_modules/x.ts",
@@ -196,7 +202,8 @@ a: {
   "resolvedModule": {
     "resolvedFileName": "/node_modules/a/index.d.ts",
     "extension": ".d.ts",
-    "isExternalLibraryImport": true
+    "isExternalLibraryImport": true,
+    "resolvedUsingTsExtension": false
   },
   "failedLookupLocations": [
     "/node_modules/a/package.json",
@@ -211,7 +218,8 @@ b: {
   "resolvedModule": {
     "resolvedFileName": "/node_modules/b/index.d.ts",
     "extension": ".d.ts",
-    "isExternalLibraryImport": true
+    "isExternalLibraryImport": true,
+    "resolvedUsingTsExtension": false
   },
   "failedLookupLocations": [
     "/node_modules/b/package.json",
diff --git a/tests/baselines/reference/reuseProgramStructure/redirect-with-getSourceFileByPath-previous-duplicate-packages.js b/tests/baselines/reference/reuseProgramStructure/redirect-with-getSourceFileByPath-previous-duplicate-packages.js
index 6af47acec2e56..f7a11625082e9 100644
--- a/tests/baselines/reference/reuseProgramStructure/redirect-with-getSourceFileByPath-previous-duplicate-packages.js
+++ b/tests/baselines/reference/reuseProgramStructure/redirect-with-getSourceFileByPath-previous-duplicate-packages.js
@@ -20,7 +20,8 @@ x: {
       "name": "x",
       "subModuleName": "index.d.ts",
       "version": "1.2.3"
-    }
+    },
+    "resolvedUsingTsExtension": false
   },
   "failedLookupLocations": [
     "/node_modules/a/node_modules/x.ts",
@@ -56,7 +57,8 @@ x: {
       "name": "x",
       "subModuleName": "index.d.ts",
       "version": "1.2.4"
-    }
+    },
+    "resolvedUsingTsExtension": false
   },
   "failedLookupLocations": [
     "/node_modules/b/node_modules/x.ts",
@@ -80,7 +82,8 @@ a: {
   "resolvedModule": {
     "resolvedFileName": "/node_modules/a/index.d.ts",
     "extension": ".d.ts",
-    "isExternalLibraryImport": true
+    "isExternalLibraryImport": true,
+    "resolvedUsingTsExtension": false
   },
   "failedLookupLocations": [
     "/node_modules/a/package.json",
@@ -95,7 +98,8 @@ b: {
   "resolvedModule": {
     "resolvedFileName": "/node_modules/b/index.d.ts",
     "extension": ".d.ts",
-    "isExternalLibraryImport": true
+    "isExternalLibraryImport": true,
+    "resolvedUsingTsExtension": false
   },
   "failedLookupLocations": [
     "/node_modules/b/package.json",
@@ -138,7 +142,8 @@ x: {
       "name": "x",
       "subModuleName": "index.d.ts",
       "version": "1.2.3"
-    }
+    },
+    "resolvedUsingTsExtension": false
   },
   "failedLookupLocations": [
     "/node_modules/a/node_modules/x.ts",
@@ -174,7 +179,8 @@ x: {
       "name": "x",
       "subModuleName": "index.d.ts",
       "version": "1.2.3"
-    }
+    },
+    "resolvedUsingTsExtension": false
   },
   "failedLookupLocations": [
     "/node_modules/b/node_modules/x.ts",
@@ -198,7 +204,8 @@ a: {
   "resolvedModule": {
     "resolvedFileName": "/node_modules/a/index.d.ts",
     "extension": ".d.ts",
-    "isExternalLibraryImport": true
+    "isExternalLibraryImport": true,
+    "resolvedUsingTsExtension": false
   },
   "failedLookupLocations": [
     "/node_modules/a/package.json",
@@ -213,7 +220,8 @@ b: {
   "resolvedModule": {
     "resolvedFileName": "/node_modules/b/index.d.ts",
     "extension": ".d.ts",
-    "isExternalLibraryImport": true
+    "isExternalLibraryImport": true,
+    "resolvedUsingTsExtension": false
   },
   "failedLookupLocations": [
     "/node_modules/b/package.json",
diff --git a/tests/baselines/reference/reuseProgramStructure/redirect-with-getSourceFileByPath-target-changes.js b/tests/baselines/reference/reuseProgramStructure/redirect-with-getSourceFileByPath-target-changes.js
index 4afced0c95b7c..83f61703a58aa 100644
--- a/tests/baselines/reference/reuseProgramStructure/redirect-with-getSourceFileByPath-target-changes.js
+++ b/tests/baselines/reference/reuseProgramStructure/redirect-with-getSourceFileByPath-target-changes.js
@@ -20,7 +20,8 @@ x: {
       "name": "x",
       "subModuleName": "index.d.ts",
       "version": "1.2.3"
-    }
+    },
+    "resolvedUsingTsExtension": false
   },
   "failedLookupLocations": [
     "/node_modules/a/node_modules/x.ts",
@@ -56,7 +57,8 @@ x: {
       "name": "x",
       "subModuleName": "index.d.ts",
       "version": "1.2.3"
-    }
+    },
+    "resolvedUsingTsExtension": false
   },
   "failedLookupLocations": [
     "/node_modules/b/node_modules/x.ts",
@@ -80,7 +82,8 @@ a: {
   "resolvedModule": {
     "resolvedFileName": "/node_modules/a/index.d.ts",
     "extension": ".d.ts",
-    "isExternalLibraryImport": true
+    "isExternalLibraryImport": true,
+    "resolvedUsingTsExtension": false
   },
   "failedLookupLocations": [
     "/node_modules/a/package.json",
@@ -95,7 +98,8 @@ b: {
   "resolvedModule": {
     "resolvedFileName": "/node_modules/b/index.d.ts",
     "extension": ".d.ts",
-    "isExternalLibraryImport": true
+    "isExternalLibraryImport": true,
+    "resolvedUsingTsExtension": false
   },
   "failedLookupLocations": [
     "/node_modules/b/package.json",
@@ -131,7 +135,8 @@ x: {
   "resolvedModule": {
     "resolvedFileName": "/node_modules/a/node_modules/x/index.d.ts",
     "extension": ".d.ts",
-    "isExternalLibraryImport": true
+    "isExternalLibraryImport": true,
+    "resolvedUsingTsExtension": false
   },
   "failedLookupLocations": [
     "/node_modules/a/node_modules/x.ts",
@@ -167,7 +172,8 @@ x: {
       "name": "x",
       "subModuleName": "index.d.ts",
       "version": "1.2.3"
-    }
+    },
+    "resolvedUsingTsExtension": false
   },
   "failedLookupLocations": [
     "/node_modules/b/node_modules/x.ts",
@@ -191,7 +197,8 @@ a: {
   "resolvedModule": {
     "resolvedFileName": "/node_modules/a/index.d.ts",
     "extension": ".d.ts",
-    "isExternalLibraryImport": true
+    "isExternalLibraryImport": true,
+    "resolvedUsingTsExtension": false
   },
   "failedLookupLocations": [
     "/node_modules/a/package.json",
@@ -206,7 +213,8 @@ b: {
   "resolvedModule": {
     "resolvedFileName": "/node_modules/b/index.d.ts",
     "extension": ".d.ts",
-    "isExternalLibraryImport": true
+    "isExternalLibraryImport": true,
+    "resolvedUsingTsExtension": false
   },
   "failedLookupLocations": [
     "/node_modules/b/package.json",
diff --git a/tests/baselines/reference/reuseProgramStructure/redirect-with-getSourceFileByPath-underlying-changes.js b/tests/baselines/reference/reuseProgramStructure/redirect-with-getSourceFileByPath-underlying-changes.js
index f8d4c09bc12a7..b22376b0f96a6 100644
--- a/tests/baselines/reference/reuseProgramStructure/redirect-with-getSourceFileByPath-underlying-changes.js
+++ b/tests/baselines/reference/reuseProgramStructure/redirect-with-getSourceFileByPath-underlying-changes.js
@@ -20,7 +20,8 @@ x: {
       "name": "x",
       "subModuleName": "index.d.ts",
       "version": "1.2.3"
-    }
+    },
+    "resolvedUsingTsExtension": false
   },
   "failedLookupLocations": [
     "/node_modules/a/node_modules/x.ts",
@@ -56,7 +57,8 @@ x: {
       "name": "x",
       "subModuleName": "index.d.ts",
       "version": "1.2.3"
-    }
+    },
+    "resolvedUsingTsExtension": false
   },
   "failedLookupLocations": [
     "/node_modules/b/node_modules/x.ts",
@@ -80,7 +82,8 @@ a: {
   "resolvedModule": {
     "resolvedFileName": "/node_modules/a/index.d.ts",
     "extension": ".d.ts",
-    "isExternalLibraryImport": true
+    "isExternalLibraryImport": true,
+    "resolvedUsingTsExtension": false
   },
   "failedLookupLocations": [
     "/node_modules/a/package.json",
@@ -95,7 +98,8 @@ b: {
   "resolvedModule": {
     "resolvedFileName": "/node_modules/b/index.d.ts",
     "extension": ".d.ts",
-    "isExternalLibraryImport": true
+    "isExternalLibraryImport": true,
+    "resolvedUsingTsExtension": false
   },
   "failedLookupLocations": [
     "/node_modules/b/package.json",
@@ -136,7 +140,8 @@ x: {
       "name": "x",
       "subModuleName": "index.d.ts",
       "version": "1.2.3"
-    }
+    },
+    "resolvedUsingTsExtension": false
   },
   "failedLookupLocations": [
     "/node_modules/a/node_modules/x.ts",
@@ -172,7 +177,8 @@ x: {
       "name": "x",
       "subModuleName": "index.d.ts",
       "version": "1.2.4"
-    }
+    },
+    "resolvedUsingTsExtension": false
   },
   "failedLookupLocations": [
     "/node_modules/b/node_modules/x.ts",
@@ -196,7 +202,8 @@ a: {
   "resolvedModule": {
     "resolvedFileName": "/node_modules/a/index.d.ts",
     "extension": ".d.ts",
-    "isExternalLibraryImport": true
+    "isExternalLibraryImport": true,
+    "resolvedUsingTsExtension": false
   },
   "failedLookupLocations": [
     "/node_modules/a/package.json",
@@ -211,7 +218,8 @@ b: {
   "resolvedModule": {
     "resolvedFileName": "/node_modules/b/index.d.ts",
     "extension": ".d.ts",
-    "isExternalLibraryImport": true
+    "isExternalLibraryImport": true,
+    "resolvedUsingTsExtension": false
   },
   "failedLookupLocations": [
     "/node_modules/b/package.json",
diff --git a/tests/baselines/reference/reuseProgramStructure/resolution-cache-follows-imports.js b/tests/baselines/reference/reuseProgramStructure/resolution-cache-follows-imports.js
index 4cb70b6e9ac1b..5ccc36f9fb50f 100644
--- a/tests/baselines/reference/reuseProgramStructure/resolution-cache-follows-imports.js
+++ b/tests/baselines/reference/reuseProgramStructure/resolution-cache-follows-imports.js
@@ -15,7 +15,8 @@ b: {
   "resolvedModule": {
     "resolvedFileName": "b.ts",
     "extension": ".ts",
-    "isExternalLibraryImport": false
+    "isExternalLibraryImport": false,
+    "resolvedUsingTsExtension": false
   }
 }
 resolvedTypeReferenceDirectiveNames: undefined
@@ -44,7 +45,8 @@ b: {
   "resolvedModule": {
     "resolvedFileName": "b.ts",
     "extension": ".ts",
-    "isExternalLibraryImport": false
+    "isExternalLibraryImport": false,
+    "resolvedUsingTsExtension": false
   }
 }
 resolvedTypeReferenceDirectiveNames: undefined
@@ -89,7 +91,8 @@ b: {
   "resolvedModule": {
     "resolvedFileName": "b.ts",
     "extension": ".ts",
-    "isExternalLibraryImport": false
+    "isExternalLibraryImport": false,
+    "resolvedUsingTsExtension": false
   }
 }
 c: {
diff --git a/tests/baselines/reference/reuseProgramStructure/resolvedImports-after-re-using-an-ambient-external-module-declaration.js b/tests/baselines/reference/reuseProgramStructure/resolvedImports-after-re-using-an-ambient-external-module-declaration.js
index 362434f1dafdd..3de657beb7949 100644
--- a/tests/baselines/reference/reuseProgramStructure/resolvedImports-after-re-using-an-ambient-external-module-declaration.js
+++ b/tests/baselines/reference/reuseProgramStructure/resolvedImports-after-re-using-an-ambient-external-module-declaration.js
@@ -8,7 +8,8 @@ a: {
   "resolvedModule": {
     "resolvedFileName": "/a.ts",
     "extension": ".ts",
-    "isExternalLibraryImport": false
+    "isExternalLibraryImport": false,
+    "resolvedUsingTsExtension": false
   }
 }
 resolvedTypeReferenceDirectiveNames: undefined
@@ -29,7 +30,8 @@ a: {
   "resolvedModule": {
     "resolvedFileName": "/a.ts",
     "extension": ".ts",
-    "isExternalLibraryImport": false
+    "isExternalLibraryImport": false,
+    "resolvedUsingTsExtension": false
   }
 }
 resolvedTypeReferenceDirectiveNames: undefined
diff --git a/tests/baselines/reference/reuseProgramStructure/works-with-updated-SourceFiles.js b/tests/baselines/reference/reuseProgramStructure/works-with-updated-SourceFiles.js
index 90c3cb70935f7..269048aa8cfd2 100644
--- a/tests/baselines/reference/reuseProgramStructure/works-with-updated-SourceFiles.js
+++ b/tests/baselines/reference/reuseProgramStructure/works-with-updated-SourceFiles.js
@@ -8,7 +8,8 @@ a: {
   "resolvedModule": {
     "resolvedFileName": "/a.ts",
     "extension": ".ts",
-    "isExternalLibraryImport": false
+    "isExternalLibraryImport": false,
+    "resolvedUsingTsExtension": false
   }
 }
 resolvedTypeReferenceDirectiveNames: undefined
@@ -30,7 +31,8 @@ a: {
   "resolvedModule": {
     "resolvedFileName": "/a.ts",
     "extension": ".ts",
-    "isExternalLibraryImport": false
+    "isExternalLibraryImport": false,
+    "resolvedUsingTsExtension": false
   }
 }
 resolvedTypeReferenceDirectiveNames: undefined
diff --git a/tests/baselines/reference/showConfig/Shows tsconfig for single option/allowImportingTsExtensions/tsconfig.json b/tests/baselines/reference/showConfig/Shows tsconfig for single option/allowImportingTsExtensions/tsconfig.json
new file mode 100644
index 0000000000000..88c95f9eb8307
--- /dev/null
+++ b/tests/baselines/reference/showConfig/Shows tsconfig for single option/allowImportingTsExtensions/tsconfig.json	
@@ -0,0 +1,5 @@
+{
+    "compilerOptions": {
+        "allowImportingTsExtensions": true
+    }
+}
diff --git a/tests/baselines/reference/tsserver/plugins/getSupportedCodeFixes-can-be-proxied.js b/tests/baselines/reference/tsserver/plugins/getSupportedCodeFixes-can-be-proxied.js
index 12b3d134c26e8..cb8ce333a59cd 100644
--- a/tests/baselines/reference/tsserver/plugins/getSupportedCodeFixes-can-be-proxied.js
+++ b/tests/baselines/reference/tsserver/plugins/getSupportedCodeFixes-can-be-proxied.js
@@ -1143,6 +1143,7 @@ Info 32   [00:01:13.000] response:
         "2842",
         "2843",
         "2844",
+        "2846",
         "4000",
         "4002",
         "4004",
@@ -1293,6 +1294,11 @@ Info 32   [00:01:13.000] response:
         "5093",
         "5094",
         "5095",
+        "5096",
+        "5097",
+        "5098",
+        "5099",
+        "5100",
         "6044",
         "6045",
         "6046",
@@ -2463,6 +2469,7 @@ Info 38   [00:01:19.000] response:
         "2842",
         "2843",
         "2844",
+        "2846",
         "4000",
         "4002",
         "4004",
@@ -2613,6 +2620,11 @@ Info 38   [00:01:19.000] response:
         "5093",
         "5094",
         "5095",
+        "5096",
+        "5097",
+        "5098",
+        "5099",
+        "5100",
         "6044",
         "6045",
         "6046",
@@ -3695,6 +3707,7 @@ Info 40   [00:01:21.000] response:
         "2842",
         "2843",
         "2844",
+        "2846",
         "4000",
         "4002",
         "4004",
@@ -3845,6 +3858,11 @@ Info 40   [00:01:21.000] response:
         "5093",
         "5094",
         "5095",
+        "5096",
+        "5097",
+        "5098",
+        "5099",
+        "5100",
         "6044",
         "6045",
         "6046",
diff --git a/tests/cases/conformance/moduleResolution/bundler/bundlerImportESM.ts b/tests/cases/conformance/moduleResolution/bundler/bundlerImportESM.ts
new file mode 100644
index 0000000000000..86107d98fbcab
--- /dev/null
+++ b/tests/cases/conformance/moduleResolution/bundler/bundlerImportESM.ts
@@ -0,0 +1,13 @@
+// @moduleResolution: bundler
+
+// @Filename: /esm.mts
+export const esm = 0;
+
+// @Filename: /not-actually-cjs.cts
+import { esm } from "./esm.mjs";
+
+// @Filename: /package.json
+{ "type": "commonjs" }
+
+// @Filename: /still-not-cjs.ts
+import { esm } from "./esm.mjs";
diff --git a/tests/cases/conformance/moduleResolution/bundler/bundlerImportTsExtensions.ts b/tests/cases/conformance/moduleResolution/bundler/bundlerImportTsExtensions.ts
new file mode 100644
index 0000000000000..8ba4b62b7116b
--- /dev/null
+++ b/tests/cases/conformance/moduleResolution/bundler/bundlerImportTsExtensions.ts
@@ -0,0 +1,73 @@
+// @moduleResolution: bundler
+// @outDir: dist
+// @allowJs: true
+// @checkJs: true
+// @outDir: out
+// @noEmit: true,false
+// @allowImportingTsExtensions: true,false
+// @traceResolution: true
+
+// @Filename: /project/a.ts
+export {};
+
+// @Filename: /project/b.ts
+export {};
+
+// @Filename: /project/b.js
+export {};
+
+// @Filename: /project/b.d.ts
+export {};
+
+// @Filename: /project/c.ts
+export {};
+
+// @Filename: /project/c.tsx
+export {};
+
+// @Filename: /project/d/index.ts
+export {};
+
+// @Filename: /project/e
+WOMP WOMP BINARY DATA
+
+// @Filename: /project/e.ts
+export {};
+
+// @Filename: /project/e.txt
+The letter e is for elephant
+This poem is not about elephants
+It is about the letter e
+- Authored by GitHub Copilot, Nov 2022
+
+// @Filename: /project/e.txt.ts
+export {};
+
+// @Filename: /project/main.ts
+import {} from "./a";
+import {} from "./a.js";
+import {} from "./a.ts";
+
+import {} from "./b";
+import {} from "./b.js";
+import {} from "./b.ts";
+import {} from "./b.d.ts";
+import type {} from "./b.d.ts";
+
+import {} from "./c.ts";
+import {} from "./c.tsx";
+
+import {} from "./d";
+import {} from "./d/index";
+import {} from "./d/index.ts";
+
+// These should not resolve, but preventing them has
+// relatively little utility compared to the cost of
+// the filesystem hits.
+import {} from "./e";
+import {} from "./e.txt";
+
+// @Filename: /project/types.d.ts
+import {} from "./a.ts";
+import {} from "./a.d.ts";
+import type {} from "./a.d.ts";
\ No newline at end of file
diff --git a/tests/cases/conformance/moduleResolution/bundler/bundlerNodeModules1.ts b/tests/cases/conformance/moduleResolution/bundler/bundlerNodeModules1.ts
new file mode 100644
index 0000000000000..ffa7242ff3c09
--- /dev/null
+++ b/tests/cases/conformance/moduleResolution/bundler/bundlerNodeModules1.ts
@@ -0,0 +1,38 @@
+// @moduleResolution: bundler
+// @traceResolution: true
+
+// @Filename: /node_modules/dual/package.json
+{
+  "name": "dual",
+  "version": "1.0.0",
+  "type": "module",
+  "main": "index.cjs",
+  "types": "index.d.cts",
+  "exports": {
+    ".": {
+      "import": "./index.js",
+      "require": "./index.cjs"
+    }
+  }
+}
+
+// @Filename: /node_modules/dual/index.js
+export const esm = 0;
+
+// @Filename: /node_modules/dual/index.d.ts
+export const esm: number;
+
+// @Filename: /node_modules/dual/index.cjs
+exports.cjs = 0;
+
+// @Filename: /node_modules/dual/index.d.cts
+export const cjs: number;
+
+// @Filename: /main.ts
+import { esm, cjs } from "dual";
+
+// @Filename: /main.mts
+import { esm, cjs } from "dual";
+
+// @Filename: /main.cts
+import { esm, cjs } from "dual";
diff --git a/tests/cases/conformance/moduleResolution/bundler/bundlerRelative1.ts b/tests/cases/conformance/moduleResolution/bundler/bundlerRelative1.ts
new file mode 100644
index 0000000000000..d23292176f8d4
--- /dev/null
+++ b/tests/cases/conformance/moduleResolution/bundler/bundlerRelative1.ts
@@ -0,0 +1,33 @@
+// @moduleResolution: bundler
+// @traceResolution: true
+
+// @Filename: /dir/index.ts
+export const x = 0;
+
+// @Filename: /redirect/package.json
+{ "main": "../foo" }
+
+// @Filename: /foo/index.ts
+export const y = 0;
+
+// @Filename: /types/esm.d.ts
+declare const _: string;
+export default _;
+
+// @Filename: /types/cjs.d.ts
+declare const _: string;
+export = _;
+
+// @Filename: /main.ts
+import { x } from "./dir";
+import {} from "./dir/index";
+import {} from "./dir/index.js";
+import {} from "./dir/index.ts";
+
+import { y } from "./redirect";
+import {} from "./redirect/index";
+
+import a from "./types/esm";
+import * as esm from "./types/esm";
+import b from "./types/cjs";
+import * as cjs from "./types/cjs";
diff --git a/tests/cases/conformance/moduleResolution/bundler/bundlerSyntaxRestrictions.ts b/tests/cases/conformance/moduleResolution/bundler/bundlerSyntaxRestrictions.ts
new file mode 100644
index 0000000000000..fdc7f7c77819d
--- /dev/null
+++ b/tests/cases/conformance/moduleResolution/bundler/bundlerSyntaxRestrictions.ts
@@ -0,0 +1,22 @@
+// @moduleResolution: bundler
+// @checkJs: true
+// @allowJs: true
+// @outDir: out
+
+// @Filename: /node_modules/@types/node/index.d.ts
+declare var require: (...args: any[]) => any;
+
+// @Filename: /mainJs.js
+import {} from "./a";
+import("./a");
+const _ = require("./a"); // No resolution
+_.a; // any
+
+// @Filename: /main.ts
+import {} from "./a";
+import _ = require("./a"); // Error
+export = {}; // Error
+export {};
+
+// @Filename: /a.ts
+export const a = "a";
diff --git a/tests/cases/conformance/moduleResolution/customConditions.ts b/tests/cases/conformance/moduleResolution/customConditions.ts
new file mode 100644
index 0000000000000..47fb048ac28bf
--- /dev/null
+++ b/tests/cases/conformance/moduleResolution/customConditions.ts
@@ -0,0 +1,31 @@
+// @moduleResolution: bundler
+// @customConditions: webpack, browser
+// @resolvePackageJsonExports: true, false
+// @traceResolution: true
+
+// @Filename: /node_modules/lodash/package.json
+{
+    "name": "lodash",
+    "version": "1.0.0",
+    "main": "index.js",
+    "exports": {
+        "browser": "./browser.js",
+        "webpack": "./webpack.js",
+        "default": "./index.js"
+    }
+}
+
+// @Filename: /node_modules/lodash/index.d.ts
+declare const _: "index";
+export = _;
+
+// @Filename: /node_modules/lodash/browser.d.ts
+declare const _: "browser";
+export default _;
+
+// @Filename: /node_modules/lodash/webpack.d.ts
+declare const _: "webpack";
+export = _;
+
+// @Filename: /index.ts
+import _ from "lodash";
diff --git a/tests/cases/conformance/moduleResolution/extensionLoadingPriority.ts b/tests/cases/conformance/moduleResolution/extensionLoadingPriority.ts
index 7686c3dfedf61..c3a06a36b52aa 100644
--- a/tests/cases/conformance/moduleResolution/extensionLoadingPriority.ts
+++ b/tests/cases/conformance/moduleResolution/extensionLoadingPriority.ts
@@ -1,4 +1,4 @@
-// @moduleResolution: classic,node,node16,nodenext
+// @moduleResolution: classic,node,node16,nodenext,bundler
 // @allowJs: true
 // @checkJs: true
 // @noEmit: true
diff --git a/tests/cases/conformance/moduleResolution/packageJsonImportsExportsOptionCompat.ts b/tests/cases/conformance/moduleResolution/packageJsonImportsExportsOptionCompat.ts
new file mode 100644
index 0000000000000..b1bf3811d6e64
--- /dev/null
+++ b/tests/cases/conformance/moduleResolution/packageJsonImportsExportsOptionCompat.ts
@@ -0,0 +1,7 @@
+// @moduleResolution: classic, node, node16, nodenext, bundler
+// @resolvePackageJsonImports: true
+// @resolvePackageJsonExports: true
+// @noTypesAndSymbols: true
+// @noEmit: true
+
+// @Filename: index.ts
\ No newline at end of file
diff --git a/tests/cases/fourslash/autoImportAllowTsExtensions1.ts b/tests/cases/fourslash/autoImportAllowTsExtensions1.ts
new file mode 100644
index 0000000000000..e71867ceb67d8
--- /dev/null
+++ b/tests/cases/fourslash/autoImportAllowTsExtensions1.ts
@@ -0,0 +1,22 @@
+/// <reference path="fourslash.ts" />
+
+// @moduleResolution: bundler
+// @allowImportingTsExtensions: true
+// @noEmit: true
+
+// @Filename: /node_modules/@types/foo/index.d.ts
+//// export const fromAtTypesFoo: number;
+
+// @Filename: /node_modules/bar/index.d.ts
+//// export const fromBar: number;
+
+// @Filename: /local.ts
+//// export const fromLocal: number;
+
+// @Filename: /Component.tsx
+//// export function Component() { return null; }
+
+// @Filename: /main.ts
+//// /**/
+
+verify.baselineAutoImports("");
diff --git a/tests/cases/fourslash/autoImportAllowTsExtensions2.ts b/tests/cases/fourslash/autoImportAllowTsExtensions2.ts
new file mode 100644
index 0000000000000..5fd8b0730bbf0
--- /dev/null
+++ b/tests/cases/fourslash/autoImportAllowTsExtensions2.ts
@@ -0,0 +1,22 @@
+/// <reference path="fourslash.ts" />
+
+// @moduleResolution: bundler
+// @allowImportingTsExtensions: true
+// @noEmit: true
+
+// @Filename: /node_modules/@types/foo/index.d.ts
+//// export const fromAtTypesFoo: number;
+
+// @Filename: /node_modules/bar/index.d.ts
+//// export const fromBar: number;
+
+// @Filename: /local.ts
+//// export const fromLocal: number;
+
+// @Filename: /Component.tsx
+//// export function Component() { return null; }
+
+// @Filename: /main.ts
+//// /**/
+
+verify.baselineAutoImports("", { importModuleSpecifierEnding: "js" });
diff --git a/tests/cases/fourslash/autoImportAllowTsExtensions3.ts b/tests/cases/fourslash/autoImportAllowTsExtensions3.ts
new file mode 100644
index 0000000000000..d6e38bf236e1d
--- /dev/null
+++ b/tests/cases/fourslash/autoImportAllowTsExtensions3.ts
@@ -0,0 +1,20 @@
+/// <reference path="fourslash.ts" />
+
+// @moduleResolution: bundler
+// @allowImportingTsExtensions: true
+// @noEmit: true
+
+// @Filename: /local.ts
+//// export const fromLocal: number;
+
+// @Filename: /decl.d.ts
+//// export const fromDecl: number;
+
+// @Filename: /Component.tsx
+//// export function Component() { return null; }
+
+// @Filename: /main.ts
+//// import { Component } from "./Component.tsx";
+//// /**/
+
+verify.baselineAutoImports("");
diff --git a/tests/cases/fourslash/autoImportAllowTsExtensions4.ts b/tests/cases/fourslash/autoImportAllowTsExtensions4.ts
new file mode 100644
index 0000000000000..b4f479fef5bf9
--- /dev/null
+++ b/tests/cases/fourslash/autoImportAllowTsExtensions4.ts
@@ -0,0 +1,20 @@
+/// <reference path="fourslash.ts" />
+
+// @moduleResolution: bundler
+// @allowImportingTsExtensions: true
+// @noEmit: true
+
+// @Filename: /local.ts
+//// export const fromLocal: number;
+
+// @Filename: /decl.d.ts
+//// export const fromDecl: number;
+
+// @Filename: /Component.tsx
+//// export function Component() { return null; }
+
+// @Filename: /main.ts
+//// import { Component } from "./local.js";
+//// /**/
+
+verify.baselineAutoImports("");
diff --git a/tests/cases/fourslash/fourslash.ts b/tests/cases/fourslash/fourslash.ts
index 7d106808e7982..5bbbd00212ccb 100644
--- a/tests/cases/fourslash/fourslash.ts
+++ b/tests/cases/fourslash/fourslash.ts
@@ -375,6 +375,7 @@ declare namespace FourSlashInterface {
         getAndApplyCodeFix(errorCode?: number, index?: number): void;
         importFixAtPosition(expectedTextArray: string[], errorCode?: number, options?: UserPreferences): void;
         importFixModuleSpecifiers(marker: string, moduleSpecifiers: string[], options?: UserPreferences): void;
+        baselineAutoImports(marker: string, options?: UserPreferences): void;
 
         navigationBar(json: any, options?: { checkSpans?: boolean }): void;
         navigationTree(json: any, options?: { checkSpans?: boolean }): void;
diff --git a/tests/cases/fourslash/pathCompletionsAllowTsExtensions.ts b/tests/cases/fourslash/pathCompletionsAllowTsExtensions.ts
new file mode 100644
index 0000000000000..b871ce1f429e4
--- /dev/null
+++ b/tests/cases/fourslash/pathCompletionsAllowTsExtensions.ts
@@ -0,0 +1,36 @@
+/// <reference path="fourslash.ts" />
+
+// @moduleResolution: bundler
+// @allowImportingTsExtensions: true
+// @noEmit: true
+
+// @Filename: /project/foo.ts
+//// export const foo = 0;
+
+// @Filename: /project/main.ts
+//// import {} from ".//**/"
+
+// Extensionless by default
+verify.completions({
+  marker: "",
+  isNewIdentifierLocation: true,
+  exact: ["foo"],
+});
+
+// .ts extension when allowImportingTsExtensions is true and setting is js...
+verify.completions({
+  marker: "",
+  isNewIdentifierLocation: true,
+  exact: ["foo.ts"],
+  preferences: {
+    importModuleSpecifierEnding: "js",
+  },
+});
+
+// ...or when another import uses .ts extension
+edit.insert(`foo.ts"\nimport {} from "./`);
+verify.completions({
+  marker: "",
+  isNewIdentifierLocation: true,
+  exact: ["foo.ts"],
+});