Port experimental-specifier-resolution tests from Node codebase

Author: GeoffreyBooth

commonjs-extension-resolution-loader/package.json

@@ -6,7 +6,7 @@
   "main": "./loader.js",
   "scripts": {
     "start": "npm test",
-    "test": "node test/basic.js"
+    "test": "node test/basic.js && node test/test-esm-specifiers.js && node test/test-esm-specifiers-symlink.js"
   },
   "author": "Geoffrey Booth <[email protected]>",
   "license": "MIT",

commonjs-extension-resolution-loader/test/common.js

@@ -0,0 +1,34 @@
+// Ported from https://github.com/nodejs/node/blob/45f2258f74117e27ffced434a98ad6babc14f7fa/test/common/index.js
+
+import { spawn } from 'node:child_process';
+
+
+export function spawnPromisified(...args) {
+  let stderr = '';
+  let stdout = '';
+
+  const child = spawn(...args);
+  child.stderr.setEncoding('utf8');
+  child.stderr.on('data', (data) => { stderr += data; });
+  child.stdout.setEncoding('utf8');
+  child.stdout.on('data', (data) => { stdout += data; });
+
+  return new Promise((resolve, reject) => {
+    child.on('close', (code, signal) => {
+      resolve({
+        code,
+        signal,
+        stderr,
+        stdout,
+      });
+    });
+    child.on('error', (code, signal) => {
+      reject({
+        code,
+        signal,
+        stderr,
+        stdout,
+      });
+    });
+  });
+}

commonjs-extension-resolution-loader/test/fixtures/es-module-specifiers/index.mjs

@@ -0,0 +1,11 @@
+import explicit from 'explicit-main';
+import implicit from 'implicit-main';
+import implicitModule from 'implicit-main-type-module';
+import noMain from 'no-main-field';
+
+function getImplicitCommonjs () {
+  return import('implicit-main-type-commonjs');
+}
+
+export {explicit, implicit, implicitModule, getImplicitCommonjs, noMain};
+export default 'success';

commonjs-extension-resolution-loader/test/fixtures/es-module-specifiers/package-type-commonjs/a.js

@@ -0,0 +1 @@
+module.exports = 'a';

commonjs-extension-resolution-loader/test/fixtures/es-module-specifiers/package-type-commonjs/b.mjs

@@ -0,0 +1 @@
+export const b = 'b';

commonjs-extension-resolution-loader/test/fixtures/es-module-specifiers/package-type-commonjs/c.cjs

@@ -0,0 +1,5 @@
+module.exports = {
+  one: 1,
+  two: 2,
+  three: 3
+};

commonjs-extension-resolution-loader/test/fixtures/es-module-specifiers/package-type-commonjs/index.mjs

@@ -0,0 +1,21 @@
+// js file that is common.js
+import a from './a.js';
+// ESM with named export
+import {b} from './b.mjs';
+// import 'c.cjs';
+import cjs from './c.cjs';
+// proves cross boundary fun bits
+import jsAsEsm from '../package-type-module/a.js';
+
+// named export from core
+import {strictEqual, deepStrictEqual} from 'assert';
+
+strictEqual(a, jsAsEsm);
+strictEqual(b, 'b');
+deepStrictEqual(cjs, {
+  one: 1,
+  two: 2,
+  three: 3
+});
+
+export default 'commonjs';

commonjs-extension-resolution-loader/test/fixtures/es-module-specifiers/package-type-commonjs/package.json

@@ -0,0 +1,3 @@
+{
+  "type": "commonjs"
+}

commonjs-extension-resolution-loader/test/fixtures/es-module-specifiers/package-type-module/a.js

@@ -0,0 +1 @@
+export default 'a'

commonjs-extension-resolution-loader/test/fixtures/es-module-specifiers/package-type-module/b.mjs

@@ -0,0 +1 @@
+export const b = 'b';