worker: add support for .cjs extension

PR-URL: #31662
Reviewed-By: Anna Henningsen <anna@addaleax.net>
Reviewed-By: Rich Trott <rtrott@gmail.com>
Reviewed-By: James M Snell <jasnell@gmail.com>
Reviewed-By: Colin Ihrig <cjihrig@gmail.com>
Reviewed-By: Ruben Bridgewater <ruben@bridgewater.de>
Reviewed-By: David Carlier <devnexen@gmail.com>
Reviewed-By: Yuta Hiroto <hello@hiroppy.me>
Reviewed-By: Gus Caplan <me@gus.host>
Reviewed-By: Denys Otrishko <shishugi@gmail.com>

lib/internal/errors.js

@@ -1356,7 +1356,7 @@ E('ERR_WORKER_PATH',
 E('ERR_WORKER_UNSERIALIZABLE_ERROR',
   'Serializing an uncaught exception failed', Error);
 E('ERR_WORKER_UNSUPPORTED_EXTENSION',
-  'The worker script extension must be ".js" or ".mjs". Received "%s"',
+  'The worker script extension must be ".js", ".mjs", or ".cjs". Received "%s"',
   TypeError);
 E('ERR_WORKER_UNSUPPORTED_OPERATION',
   '%s is not supported in workers', TypeError);

lib/internal/worker.js

@@ -103,7 +103,7 @@ class Worker extends EventEmitter {
       filename = path.resolve(filename);
 
       const ext = path.extname(filename);
-      if (ext !== '.js' && ext !== '.mjs') {
+      if (!/^\.[cm]?js$/.test(ext)) {
         throw new ERR_WORKER_UNSUPPORTED_EXTENSION(ext);
       }
     }

test/fixtures/worker-data.cjs

@@ -0,0 +1,3 @@
+const { workerData, parentPort } = require('worker_threads');
+
+parentPort.postMessage(workerData);

test/parallel/test-worker-cjs-workerdata.js

@@ -0,0 +1,15 @@
+'use strict';
+const common = require('../common');
+const fixtures = require('../common/fixtures');
+const assert = require('assert');
+const { Worker } = require('worker_threads');
+
+const workerData = 'Hello from main thread';
+
+const worker = new Worker(fixtures.path('worker-data.cjs'), {
+  workerData
+});
+
+worker.on('message', common.mustCall((message) => {
+  assert.strictEqual(message, workerData);
+}));