Implement support for transforming snapshot resolvers

e2e/__tests__/transform.test.ts

@@ -185,3 +185,16 @@ describe('transformer-config', () => {
     expect(stdout).toMatchSnapshot();
   });
 });
+
+describe('transform-snapshotResolver', () => {
+  const dir = path.resolve(
+    __dirname,
+    '../transform/transform-snapshotResolver',
+  );
+  it('should transform the snapshotResolver', () => {
+    const {json, stderr} = runWithJson(dir, ['--no-cache']);
+    expect(stderr).toMatch(/PASS/);
+    expect(json.success).toBe(true);
+    expect(json.numPassedTests).toBe(1);
+  });
+});

e2e/transform/transform-snapshotResolver/__snapshots__/add.test.js.snap

@@ -0,0 +1,3 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`should add two numbers 1`] = `"hello world"`;

e2e/transform/transform-snapshotResolver/__tests__/add.test.js

@@ -0,0 +1,10 @@
+/**
+ * Copyright (c) Facebook, Inc. and its affiliates. All Rights Reserved.
+ *
+ * This source code is licensed under the MIT license found in the
+ * LICENSE file in the root directory of this source tree.
+ */
+
+it('should add two numbers', () => {
+  expect('hello world').toMatchSnapshot();
+});

e2e/transform/transform-snapshotResolver/babel.config.js

@@ -0,0 +1,18 @@
+/**
+ * Copyright (c) Facebook, Inc. and its affiliates. All Rights Reserved.
+ *
+ * This source code is licensed under the MIT license found in the
+ * LICENSE file in the root directory of this source tree.
+ */
+
+module.exports = {
+  presets: [
+    '@babel/preset-typescript',
+    [
+      '@babel/preset-env',
+      {
+        targets: {node: 'current'},
+      },
+    ],
+  ],
+};

e2e/transform/transform-snapshotResolver/package.json

@@ -0,0 +1,9 @@
+{
+  "jest": {
+    "snapshotResolver": "<rootDir>/snapshotResolver.ts"
+  },
+  "dependencies": {
+    "@babel/preset-env": "^7.0.0",
+    "@babel/preset-typescript": "^7.0.0"
+  }
+}

e2e/transform/transform-snapshotResolver/snapshotResolver.ts

@@ -0,0 +1,22 @@
+/**
+ * Copyright (c) Facebook, Inc. and its affiliates. All Rights Reserved.
+ *
+ * This source code is licensed under the MIT license found in the
+ * LICENSE file in the root directory of this source tree.
+ */
+
+import {SnapshotResolver} from 'jest-snapshot';
+
+const snapshotResolver: SnapshotResolver = {
+  resolveSnapshotPath: (testPath, snapshotExtension) =>
+    testPath.replace('__tests__', '__snapshots__') + snapshotExtension,
+
+  resolveTestPath: (snapshotFilePath, snapshotExtension) =>
+    snapshotFilePath
+      .replace('__snapshots__', '__tests__')
+      .slice(0, -(snapshotExtension || '').length),
+
+  testPathForConsistencyCheck: 'some/__tests__/example.test.js',
+};
+
+export default snapshotResolver;

e2e/transform/transform-snapshotResolver/tsconfig.json

@@ -0,0 +1,5 @@
+{
+  "compilerOptions": {
+    "module": "commonjs"
+  }
+}

packages/jest-circus/src/legacy-code-todo-rewrite/jestAdapterInit.ts

@@ -122,7 +122,7 @@ export const initialize = ({
     });
 
   const {expand, updateSnapshot} = globalConfig;
-  const snapshotResolver = buildSnapshotResolver(config);
+  const snapshotResolver = buildSnapshotResolver(config, localRequire);
   const snapshotPath = snapshotResolver.resolveSnapshotPath(testPath);
   const snapshotState = new SnapshotState(snapshotPath, {
     expand,

packages/jest-jasmine2/src/setup_jest_globals.ts

@@ -101,7 +101,7 @@ export default ({
 
   patchJasmine();
   const {expand, updateSnapshot} = globalConfig;
-  const snapshotResolver = buildSnapshotResolver(config);
+  const snapshotResolver = buildSnapshotResolver(config, localRequire);
   const snapshotPath = snapshotResolver.resolveSnapshotPath(testPath);
   const snapshotState = new SnapshotState(snapshotPath, {
     expand,

packages/jest-snapshot/package.json

@@ -11,6 +11,7 @@
   "types": "build/index.d.ts",
   "dependencies": {
     "@babel/types": "^7.0.0",
+    "@jest/transform": "^24.8.0",
     "@jest/types": "^24.8.0",
     "chalk": "^2.0.1",
     "expect": "^24.8.0",
@@ -19,6 +20,7 @@
     "jest-matcher-utils": "^24.8.0",
     "jest-message-util": "^24.8.0",
     "jest-resolve": "^24.8.0",
+    "jest-util": "^24.8.0",
     "mkdirp": "^0.5.1",
     "natural-compare": "^1.4.0",
     "pretty-format": "^24.8.0",

packages/jest-snapshot/src/snapshot_resolver.ts

@@ -6,6 +6,8 @@
  */
 
 import path from 'path';
+import {ScriptTransformer} from '@jest/transform';
+import {interopRequireDefault} from 'jest-util';
 import {Config} from '@jest/types';
 import chalk from 'chalk';
 
@@ -22,21 +24,33 @@ export const isSnapshotPath = (path: string): boolean =>
   path.endsWith(DOT_EXTENSION);
 
 const cache: Map<Config.Path, SnapshotResolver> = new Map();
+const buildDefaultResolverRequire = (config: Config.ProjectConfig) => (
+  snapshotResolverPath: string,
+) =>
+  new ScriptTransformer(config).requireAndTranspileModule<SnapshotResolver>(
+    snapshotResolverPath,
+  );
+
 export const buildSnapshotResolver = (
   config: Config.ProjectConfig,
+  localRequire: (module: string) => any = buildDefaultResolverRequire(config),
 ): SnapshotResolver => {
   const key = config.rootDir;
   if (!cache.has(key)) {
-    cache.set(key, createSnapshotResolver(config.snapshotResolver));
+    cache.set(
+      key,
+      createSnapshotResolver(localRequire, config.snapshotResolver),
+    );
   }
   return cache.get(key)!;
 };
 
 function createSnapshotResolver(
+  localRequire: (moduleName: string) => SnapshotResolver,
   snapshotResolverPath?: Config.Path | null,
 ): SnapshotResolver {
   return typeof snapshotResolverPath === 'string'
-    ? createCustomSnapshotResolver(snapshotResolverPath)
+    ? createCustomSnapshotResolver(snapshotResolverPath, localRequire)
     : createDefaultSnapshotResolver();
 }
 
@@ -65,8 +79,11 @@ function createDefaultSnapshotResolver(): SnapshotResolver {
 
 function createCustomSnapshotResolver(
   snapshotResolverPath: Config.Path,
+  localRequire: (moduleName: string) => SnapshotResolver,
 ): SnapshotResolver {
-  const custom: SnapshotResolver = require(snapshotResolverPath);
+  const custom: SnapshotResolver = interopRequireDefault(
+    localRequire(snapshotResolverPath),
+  ).default;
 
   const keys: Array<[keyof SnapshotResolver, string]> = [
     ['resolveSnapshotPath', 'function'],

packages/jest-snapshot/tsconfig.json

@@ -12,6 +12,8 @@
     {"path": "../jest-matcher-utils"},
     {"path": "../jest-message-util"},
     {"path": "../jest-resolve"},
+    {"path": "../jest-util"},
+    {"path": "../jest-transform" },
     {"path": "../jest-types"},
     {"path": "../pretty-format"}
   ]