Fix/issue support js index files fix 260 (#261)

* Fix an ESM index.js/.mjs/.cjs import edge case

In [1] a removeFileExtensionToAllowForJs() utility function has been
added to help with normalizing import paths into extensionless ones in
order to handle ESM imports (which have to have extensions, either .js,
.mjs or .cjs).

One thing was missed though as index files are handled in a special way.

In the analyzer.ts:

    const processImports = (file: File, exportMap: ExportMap): void => {
      Object.keys(file.imports).forEach((key) => {
        let ex = exportMap[removeFileExtensionToAllowForJs(key)]?.exports;

exportMap had keys with extensions and "index" removed (so that
"xxx/index.ts" became "xxx" there) but paths in file.imports came from
getFromText() which only handled extensionless index imports so
xxx/index.js" stayed "xxx/index.js". The .js extension was then removed
by removeFileExtensionToAllowForJs() but the damage was done already and
"xxx" != "xxx/index".

This change brings the removeFileExtensionToAllowForJs()-like
ESM-compatible behavior to getFromText().

[1] 6e506ae ("Add .js extension support with es6 example (#255)")

* Fix test cleanup. Up changelog

* Bump package.json and changelog

Co-authored-by: Jakub Stasiak <[email protected]>

CHANGELOG.md

@@ -1,4 +1,8 @@
-### Added
+## [9.0.1] - 4 Jan 2023
+
+### Changed
+
+- Fix for index files that end with .js or .cjs or .mjs.
 
 ## [9.0.0] - 26 Dec 2022
 

features/index.feature

@@ -18,6 +18,24 @@ Scenario: Import './index'
   When analyzing "tsconfig.json"
   Then the result is {}
 
+Scenario: Import './index.js'
+  Given file "index.ts" is export const a = 1;
+  And file "a.ts" is import { a } from './index.js';
+  When analyzing "tsconfig.json"
+  Then the result is {}
+
+Scenario: Import './index.mjs'
+  Given file "index.mts" is export const a = 1;
+  And file "a.ts" is import { a } from './index.mjs';
+  When analyzing "tsconfig.json"
+  Then the result is {}
+
+Scenario: Import './index.cjs'
+  Given file "index.cts" is export const a = 1;
+  And file "a.ts" is import { a } from './index.cjs';
+  When analyzing "tsconfig.json"
+  Then the result is {}
+
 Scenario: Import './index' TSX
   Given file "index.tsx" is export const a = 1;
   And file "a.ts" is import { a } from './index';

package.json

@@ -1,6 +1,6 @@
 {
   "name": "ts-unused-exports",
-  "version": "9.0.0",
+  "version": "9.0.1",
   "description": "ts-unused-exports finds unused exported symbols in your Typescript project",
   "main": "lib/app.js",
   "repository": {

src/parser/common.ts

@@ -11,7 +11,7 @@ export interface FromWhat {
 const TRIM_QUOTES = /^['"](.*)['"]$/;
 
 export const getFromText = (moduleSpecifier: string): string =>
-  moduleSpecifier.replace(TRIM_QUOTES, '$1').replace(/\/index$/, '');
+  moduleSpecifier.replace(TRIM_QUOTES, '$1').replace(/\/index(.[mc]?js)?$/, '');
 
 export const getFrom = (moduleSpecifier: ts.Expression): string =>
   getFromText(moduleSpecifier.getText());

src/test.ts

@@ -64,7 +64,9 @@ const setup: SetupFn = ({
       const items = readdirSync(path, { encoding: 'utf8' }).filter(
         (f) => f[0] !== '.',
       );
-      const files = items.filter((f) => !!f.match(/\.(json|ts|tsx|js|jsx)$/));
+      const files = items.filter(
+        (f) => !!f.match(/\.(json|ts|tsx|js|jsx|mjs|cjs|mts|cts)$/),
+      );
       files.forEach((f) => unlinkSync(join(path, f)));
       const dirs = items.filter((i) => !files.includes(i));
       dirs.forEach((d) => removeDir(join(path, d)));