Rename jest-resolver.js to jest-resolver.cjs (#203)

Co-authored-by: Laurin Quast <laurinquast@googlemail.com>

Author: ardatan

.changeset/red-badgers-shop.md

@@ -0,0 +1,13 @@
+---
+'bob-the-bundler': major
+---
+
+**Breaking** `jest-resolver.js` renamed to `jest-resolver.cjs` because Bob package is an ESM
+package.
+
+Please make sure to adjust your `jest.config.js`.
+
+```diff
+- resolver: 'bob-the-bundler/jest-resolver.js'
++ resolver: 'bob-the-bundler/jest-resolver.cjs'
+```

.prettierignore

@@ -1,3 +1,4 @@
 dist/
 .bob/
 test/ts-tests/fixture.js
+jest.resolver.cjs

jest-resolver.js jest-resolver.cjs

@@ -1,4 +1,11 @@
-module.exports = (path, options) => {
+// @ts-check
+
+/** This is module.exports for a reason. Please don't change it. */
+/**
+ * @param {string} path
+ * @param {import("jest-resolve").ResolverOptions} options
+ */
+module.exports = function jestResolver(path, options) {
   /**
    * Jest does not like .js extensions when not running Jest in EXPERIMENTAL AND TOTALLY UNSTABLE YELL-AT-YA esm mode.
    * We rewrite it so we can run the tests.

package.json

@@ -17,9 +17,15 @@
     "bob": "dist/index.js"
   },
   "main": "dist/index.js",
+  "exports": {
+    "./jest-resolver": {
+      "default": "./jest-resolver.cjs"
+    },
+    "./package.json": "./package.json"
+  },
   "files": [
     "dist",
-    "jest-resolver.js",
+    "jest-resolver.cjs",
     "README.md"
   ],
   "scripts": {
@@ -67,6 +73,7 @@
     "@typescript-eslint/parser": "5.53.0",
     "eslint": "8.35.0",
     "eslint-plugin-import": "2.27.5",
+    "jest-resolve": "29.4.2",
     "jest-snapshot-serializer-raw": "1.2.0",
     "prettier": "2.8.4",
     "rimraf": "4.1.2",

test/jest-resolver.test.ts

@@ -0,0 +1,33 @@
+import { expect, it, test } from 'vitest';
+import * as jestResolver from '../jest-resolver.cjs';
+
+test('jest-resolver', () => {
+  it('removes .js extension from relative paths', () => {
+    const result = jestResolver('./foo.js', {
+      basedir: __dirname,
+      defaultResolver: path => path,
+    });
+    expect(result).toBe('./foo');
+  });
+  it('ignores absolute paths', () => {
+    const result = jestResolver('/Users/username/project/foo', {
+      basedir: __dirname,
+      defaultResolver: path => path,
+    });
+    expect(result).toBe('/Users/username/project/foo');
+  });
+  it('ignores relative paths from node_modules', () => {
+    const result = jestResolver('./foo', {
+      basedir: '/Users/username/project/node_modules/foo',
+      defaultResolver: path => path,
+    });
+    expect(result).toBe('./foo');
+  });
+  it('ignores non-js imports', () => {
+    const result = jestResolver('./foo.graphql', {
+      basedir: __dirname,
+      defaultResolver: path => path,
+    });
+    expect(result).toBe('./foo.graphql');
+  });
+});