Rename jest-resolver.js to jest-resolver.cjs

.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'
+```

.gitignore

@@ -7,3 +7,4 @@ public/
 *.map
 .bob/
 *.log
+jest-resolver.cjs

jest-resolver.js → jest-resolver.ts

@@ -1,4 +1,6 @@
-module.exports = (path, options) => {
+import { ResolverOptions } from 'jest-resolve';
+
+export default function jestResolver(path: string, options: ResolverOptions) {
   /**
    * 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.
@@ -17,4 +19,4 @@ module.exports = (path, options) => {
   return options.defaultResolver(path, {
     ...options,
   });
-};
+}

package.json

@@ -17,13 +17,20 @@
     "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": {
     "build": "rimraf dist && tsc",
+    "build-jest-resolver": "rimraf jest-resolver.cjs && tsc jest-resolver.ts --module commonjs && mv jest-resolver.js jest-resolver.cjs",
     "lint": "eslint --cache --cache-location node_modules/.cache/.eslintcache --ignore-path .gitignore .",
     "lint:prettier": "prettier --cache --check .",
     "prepublish": "yarn build",
@@ -67,6 +74,7 @@
     "@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 jestResolver from '../jest-resolver';
+
+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');
+  });
+});