From 77125bc27adf43a83cdbc240cb8a3f6fc9500ead Mon Sep 17 00:00:00 2001
From: Antoine du HAMEL <duhamelantoine1995@gmail.com>
Date: Thu, 6 Feb 2020 15:39:47 +0100
Subject: [PATCH] worker_threads: add support for .cjs extension

---
 lib/internal/errors.js                      |  2 +-
 lib/internal/worker.js                      |  2 +-
 test/fixtures/worker-data.cjs               |  3 +++
 test/parallel/test-worker-cjs-workerdata.js | 15 +++++++++++++++
 4 files changed, 20 insertions(+), 2 deletions(-)
 create mode 100644 test/fixtures/worker-data.cjs
 create mode 100644 test/parallel/test-worker-cjs-workerdata.js

diff --git a/lib/internal/errors.js b/lib/internal/errors.js
index 0d88a92eb41ecc..8f2af51472ba55 100644
--- a/lib/internal/errors.js
+++ b/lib/internal/errors.js
@@ -1371,7 +1371,7 @@ 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);
diff --git a/lib/internal/worker.js b/lib/internal/worker.js
index 683b1f6e6db8c7..d39150b8f208a7 100644
--- a/lib/internal/worker.js
+++ b/lib/internal/worker.js
@@ -104,7 +104,7 @@ 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);
       }
     }
diff --git a/test/fixtures/worker-data.cjs b/test/fixtures/worker-data.cjs
new file mode 100644
index 00000000000000..731b77eb367863
--- /dev/null
+++ b/test/fixtures/worker-data.cjs
@@ -0,0 +1,3 @@
+const { workerData, parentPort } = require('worker_threads');
+
+parentPort.postMessage(workerData);
diff --git a/test/parallel/test-worker-cjs-workerdata.js b/test/parallel/test-worker-cjs-workerdata.js
new file mode 100644
index 00000000000000..949011fee8173e
--- /dev/null
+++ b/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);
+}));