Add .js extension support with es6 example (#255)

* Add es6 example

* Add more examples that import js

* Allow for import of x.js

* Refactor

* Add more extensions

CHANGELOG.md

@@ -1,3 +1,8 @@
+
+### Added
+
+Allow for importing of 'x.js' files as opposed to simply 'x'. This aims towards supporting es6 and higher modules as opposed to CommonJS.
+
 ## [8.0.5] - 10 Dec 2022
 
 ### Changed

example/simple-es5-js/app.ts

@@ -0,0 +1,3 @@
+import inc from './math.js';
+
+console.log('two', inc(1));

example/simple-es5-js/execute.sh

@@ -0,0 +1 @@
+npx tsc && node ./lib/app.js

example/simple-es5-js/math.ts

@@ -0,0 +1,6 @@
+export function unused1(x: number) { return x + 1; }
+
+// ts-unused-exports:disable-next-line
+export function unusedButDisabled(x: number) { return x + 2; }
+
+export default (x: number) => x + 1;

example/simple-es5-js/tsconfig.json

@@ -0,0 +1,11 @@
+{
+    "compilerOptions":
+    {
+      "target": "ES5",
+      "module": "commonjs",
+      "noImplicitAny": true,
+      "strictNullChecks": true,
+      "outDir": "./lib",
+    },
+    "include": ["./**/*.ts"],
+  }

example/simple-es5-js/unused.ts

@@ -0,0 +1 @@
+export function unused(x: number) { return x + 2; }

example/simple-es6/app.ts

@@ -0,0 +1,3 @@
+import * as inc from './math.js';
+
+console.log('two', inc.default(1));

example/simple-es6/execute.sh

@@ -0,0 +1 @@
+npx tsc && node ./lib/app.js

example/simple-es6/math.ts

@@ -0,0 +1,6 @@
+export function unused1(x: number) { return x + 100; }
+
+// ts-unused-exports:disable-next-line
+export function unusedButDisabled(x: number) { return x + 2; }
+
+export default (x: number) => x + 1;

example/simple-es6/package.json

@@ -0,0 +1,15 @@
+{
+    "description": "Example used by integration tests (ispec)",
+    "repository": {
+        "type": "git",
+        "url": "https://github.com/pzavolinsky/ts-unused-exports.git"
+    },
+    "license": "MIT",
+    "scripts": {
+        "test": "npm i && ../../bin/ts-unused-exports ./tsconfig.json"
+    },
+    "type": "module",
+    "dependencies": {
+        "typescript": "^4.9.4"
+    }
+}

example/simple-es6/tsconfig.json

@@ -0,0 +1,10 @@
+{
+  "compilerOptions": {
+    "target": "es6",
+    "module": "es6",
+    "noImplicitAny": true,
+    "strictNullChecks": true,
+    "outDir": "./lib",
+  },
+  "include": ["./**/*.ts"],
+}

example/simple-es6/unused.ts

@@ -0,0 +1 @@
+export function unused(x: number) { return x + 2; }

example/simple/execute.sh

@@ -0,0 +1 @@
+npx tsc && node ./lib/app.js

example/simple/tsconfig.json

@@ -1,10 +1,11 @@
 {
-  "compilerOptions": {
+  "compilerOptions":
+  {
     "target": "ES5",
     "module": "commonjs",
-    "noEmit": true,
     "noImplicitAny": true,
-    "strictNullChecks": true
+    "strictNullChecks": true,
+    "outDir": "./lib",
   },
   "include": ["./**/*.ts"],
 }

features/import-alias.feature

@@ -14,8 +14,8 @@ Scenario: Used export default - import * as x
   Given file "a.ts" is export default 1;
   And file "b.ts" is import * as ax from './a';
   When analyzing "tsconfig.json"
-  Then the result at a.ts is ["default"]
-# see star.feature - Import * marks 'default' as unused
+  Then the result is {}
+# see star.feature - Import * does NOT mark 'default' as unused
 
 Scenario: Used export default - import x
   Given file "a.ts" is export default 1;

features/star.feature

@@ -1,15 +1,15 @@
 Feature: import * / export *
 
-Scenario: Import * marks 'default' as unused
+Scenario: Import * does NOT mark 'default' as unused
   Given file "a.ts" is
     """
     export const a = 1;
     export default 1;
     """
   And file "b.ts" is import * as all from './a';
   When analyzing "tsconfig.json"
-  Then the result at a.ts is ["default"]
-# note: default could still be used, as all.default
+  Then the result is {}
+# note: a or default could still be used, as all.a or all.default - so safest to mark as used
 
 Scenario: Import * and default
   Given file "a.ts" is

package.json

@@ -1,6 +1,6 @@
 {
   "name": "ts-unused-exports",
-  "version": "8.0.5",
+  "version": "9.0.0",
   "description": "ts-unused-exports finds unused exported symbols in your Typescript project",
   "main": "lib/app.js",
   "repository": {

src/analyzer.ts

@@ -4,7 +4,11 @@ import {
   File,
   LocationInFile,
 } from './types';
-import { indexCandidates, removeExportStarPrefix } from './parser/util';
+import {
+  indexCandidates,
+  removeExportStarPrefix,
+  removeFileExtensionToAllowForJs,
+} from './parser/util';
 
 export { Analysis } from './types';
 
@@ -69,7 +73,7 @@ const getExportMap = (files: File[]): ExportMap => {
 
 const processImports = (file: File, exportMap: ExportMap): void => {
   Object.keys(file.imports).forEach((key) => {
-    let ex = exportMap[key]?.exports;
+    let ex = exportMap[removeFileExtensionToAllowForJs(key)]?.exports;
 
     // Handle imports from an index file
     if (!ex && key === '.') {
@@ -101,13 +105,9 @@ const processImports = (file: File, exportMap: ExportMap): void => {
       ex[imp].usageCount++;
     };
 
-    file.imports[key].forEach((imp) =>
-      imp === '*'
-        ? Object.keys(ex)
-            .filter((e) => e != 'default')
-            .forEach(addUsage)
-        : addUsage(imp),
-    );
+    file.imports[key].forEach((imp) => {
+      imp === '*' ? Object.keys(ex).forEach(addUsage) : addUsage(imp);
+    });
   });
 };
 

src/parser/import.ts

@@ -12,15 +12,33 @@ import path = require('path');
 
 // Parse Imports
 
-const EXTENSIONS = ['.d.ts', '.ts', '.tsx', '.js', '.jsx'];
+const EXTENSIONS = [
+  '.d.ts',
+  '.ts',
+  '.cts',
+  '.mts',
+  '.tsx',
+  '.js',
+  '.cjs',
+  '.mjs',
+  '.jsx',
+];
 
 const isRelativeToBaseDir = (baseDir: string, from: string): boolean =>
   existsSync(resolve(baseDir, `${from}.js`)) ||
+  existsSync(resolve(baseDir, `${from}.cjs`)) ||
+  existsSync(resolve(baseDir, `${from}.mjs`)) ||
   existsSync(resolve(baseDir, `${from}.ts`)) ||
+  existsSync(resolve(baseDir, `${from}.cts`)) ||
+  existsSync(resolve(baseDir, `${from}.mts`)) ||
   existsSync(resolve(baseDir, `${from}.d.ts`)) ||
   existsSync(resolve(baseDir, `${from}.tsx`)) ||
   existsSync(resolve(baseDir, from, 'index.js')) ||
+  existsSync(resolve(baseDir, from, 'index.cjs')) ||
+  existsSync(resolve(baseDir, from, 'index.mjs')) ||
   existsSync(resolve(baseDir, from, 'index.ts')) ||
+  existsSync(resolve(baseDir, from, 'index.cts')) ||
+  existsSync(resolve(baseDir, from, 'index.mts')) ||
   existsSync(resolve(baseDir, from, 'index.tsx'));
 
 const joinWithBaseUrl = (baseUrl: string, from: string) => {

src/parser/util.ts

@@ -9,10 +9,26 @@ export function isUnique<T>(value: T, index: number, self: T[]): boolean {
 export const indexCandidates = [
   '/index',
   '/index.ts',
+  '/index.cts',
+  '/index.mts',
   '/index.tsx',
   '/index.js',
+  '/index.cjs',
+  '/index.mjs',
 ];
 
+export function removeFileExtensionToAllowForJs(path: string): string {
+  // ref: https://www.typescriptlang.org/docs/handbook/esm-node.html
+  const extensionsToStrip = ['.js', '.cjs', '.mjs'];
+
+  for (let i = 0; i < extensionsToStrip.length; i++) {
+    const ext = extensionsToStrip[i];
+    if (path.endsWith(ext)) return path.substring(0, path.length - ext.length);
+  }
+
+  return path;
+}
+
 export function removeExportStarPrefix(path: string): string {
   if (path.startsWith('*:')) return path.slice(2);
   else if (path.startsWith('*as:')) return path.slice(4);