fix(scope): Recognise destructured constants.

Closes #54.
cartant · Aug 1, 2018 · 53af1d4 · 53af1d4
1 parent a72b5e5
commit 53af1d4
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Showing 4 changed files with 35 additions and 20 deletions.
diff --git a/source/rules/rxjsNoUnsafeScopeRule.ts b/source/rules/rxjsNoUnsafeScopeRule.ts
@@ -8,7 +8,7 @@ import * as Lint from "tslint";
 import * as ts from "typescript";
 import * as tsutils from "tsutils";
 import { ScopeWalker } from "../support/scope-walker";
-import { isThis, isWithinCallExpressionExpression } from "../support/util";
+import { isConstDeclaration, isThis, isWithinCallExpressionExpression } from "../support/util";
 
 export class Rule extends Lint.Rules.TypedRule {
 
@@ -128,10 +128,8 @@ class Walker extends ScopeWalker {
             }
         }
 
-        if (tsutils.isVariableDeclarationList(declaration.parent)) {
-            if (tsutils.getVariableDeclarationKind(declaration.parent) === tsutils.VariableDeclarationKind.Const) {
-                return false;
-            }
+        if (isConstDeclaration(declaration)) {
+            return false;
         }
 
         if (tsutils.isImportSpecifier(declaration)) {

diff --git a/source/rules/rxjsNoUnsafeTakewhileRule.ts b/source/rules/rxjsNoUnsafeTakewhileRule.ts
@@ -8,7 +8,7 @@ import * as Lint from "tslint";
 import * as ts from "typescript";
 import * as tsutils from "tsutils";
 import { ScopeWalker } from "../support/scope-walker";
-import { couldBeType, isThis } from "../support/util";
+import { isConstDeclaration, isThis } from "../support/util";
 
 export class Rule extends Lint.Rules.TypedRule {
 
@@ -80,10 +80,8 @@ class Walker extends ScopeWalker {
             }
         }
 
-        if (tsutils.isVariableDeclarationList(declaration.parent)) {
-            if (tsutils.getVariableDeclarationKind(declaration.parent) === tsutils.VariableDeclarationKind.Const) {
-                return false;
-            }
+        if (isConstDeclaration(declaration)) {
+            return false;
         }
 
         if (tsutils.isImportSpecifier(declaration)) {

diff --git a/source/support/util.ts b/source/support/util.ts
@@ -24,6 +24,24 @@ export function couldBeType(type: ts.Type, name: string | RegExp): boolean {
     return Boolean(baseTypes) && baseTypes.some((t) => couldBeType(t, name));
 }
 
+export function isConstDeclaration(declaration: ts.Declaration): boolean {
+
+    if (tsutils.isVariableDeclaration(declaration)) {
+        if (tsutils.isVariableDeclarationList(declaration.parent)) {
+            return tsutils.getVariableDeclarationKind(declaration.parent) === tsutils.VariableDeclarationKind.Const;
+        }
+    } else if (tsutils.isBindingElement(declaration)) {
+        let parent: ts.Node = declaration.parent;
+        while (tsutils.isBindingPattern(parent) || tsutils.isVariableDeclaration(parent)) {
+            parent = parent.parent;
+        }
+        if (tsutils.isVariableDeclarationList(parent)) {
+            return tsutils.getVariableDeclarationKind(parent) === tsutils.VariableDeclarationKind.Const;
+        }
+    }
+    return false;
+}
+
 export function isReferenceType(type: ts.Type): type is ts.TypeReference {
 
     return tsutils.isTypeFlagSet(type, ts.TypeFlags.Object) &&

diff --git a/test/v6/fixtures/issues/54/fixture.ts.lint b/test/v6/fixtures/issues/54/fixture.ts.lint
@@ -1,18 +1,19 @@
 import { of } from "rxjs";
 import { map, tap } from "rxjs/operators";
 
-ok_mapAnArray () {
-  const q = '123'
-  return [ 1, 2, 3 ].map(val => {
-    return `${q}-${val}`
-  })
+function mapAnArray() {
+  const q = '123';
+  return [1, 2, 3].map(val => `${q}-${val}`);
 }
 
-notOk_mapAnArrayFromParam (input: { q: string }) {
-  const { q } = input
-  return [ 1, 2, 3 ].map(val => {
-    return `${q}-${val}`
-  })
+function mapAnArrayFromParam (input: { q: string }) {
+  const { q } = input;
+  return [1, 2, 3].map(val => `${q}-${val}`);
+}
+
+function mapAnArrayFromRestParams (...inputs: string[]) {
+  const [q] = inputs;
+  return [1, 2, 3].map(val => `${q}-${val}`);
 }
 
 [no-unsafe-scope]: Unsafe scopes are forbidden