http: expose websockets

PR-URL: #53721
Reviewed-By: Matteo Collina <matteo.collina@gmail.com>
Reviewed-By: Paolo Insogna <paolo@cowtech.it>
Reviewed-By: James M Snell <jasnell@gmail.com>

doc/api/http.md

@@ -4228,6 +4228,15 @@ added:
 
 Set the maximum number of idle HTTP parsers.
 
+## `WebSocket`
+
+<!-- YAML
+added:
+  - REPLACEME
+-->
+
+A browser-compatible implementation of [`WebSocket`][].
+
 [RFC 8187]: https://www.rfc-editor.org/rfc/rfc8187.txt
 [`'ERR_HTTP_CONTENT_LENGTH_MISMATCH'`]: errors.md#err_http_content_length_mismatch
 [`'checkContinue'`]: #event-checkcontinue
@@ -4244,6 +4253,7 @@ Set the maximum number of idle HTTP parsers.
 [`Headers`]: globals.md#class-headers
 [`TypeError`]: errors.md#class-typeerror
 [`URL`]: url.md#the-whatwg-url-api
+[`WebSocket`]: #websocket
 [`agent.createConnection()`]: #agentcreateconnectionoptions-callback
 [`agent.getName()`]: #agentgetnameoptions
 [`destroy()`]: #agentdestroy

lib/http.js

@@ -42,6 +42,7 @@ const {
   ServerResponse,
 } = require('_http_server');
 let maxHeaderSize;
+let undici;
 
 /**
  * Returns a new instance of `http.Server`.
@@ -114,6 +115,14 @@ function get(url, options, cb) {
   return req;
 }
 
+/**
+ * Lazy loads WebSocket, CloseEvent and MessageEvent classes from undici
+ * @returns {object} An object containing WebSocket, CloseEvent, and MessageEvent classes.
+ */
+function lazyUndici() {
+  return undici ??= require('internal/deps/undici/undici');
+}
+
 module.exports = {
   _connectionListener,
   METHODS: methods.toSorted(),
@@ -160,3 +169,30 @@ ObjectDefineProperty(module.exports, 'globalAgent', {
     httpAgent.globalAgent = value;
   },
 });
+
+ObjectDefineProperty(module.exports, 'WebSocket', {
+  __proto__: null,
+  configurable: true,
+  enumerable: true,
+  get() {
+    return lazyUndici().WebSocket;
+  },
+});
+
+ObjectDefineProperty(module.exports, 'CloseEvent', {
+  __proto__: null,
+  configurable: true,
+  enumerable: true,
+  get() {
+    return lazyUndici().CloseEvent;
+  },
+});
+
+ObjectDefineProperty(module.exports, 'MessageEvent', {
+  __proto__: null,
+  configurable: true,
+  enumerable: true,
+  get() {
+    return lazyUndici().MessageEvent;
+  },
+});

test/parallel/test-http-import-websocket.js

@@ -0,0 +1,12 @@
+'use strict';
+
+require('../common');
+const assert = require('assert');
+const {
+  WebSocket: NodeHttpWebSocket,
+  MessageEvent: NodeHttpMessageEvent
+} = require('node:http');
+
+// Compare with global objects
+assert.strictEqual(NodeHttpWebSocket, WebSocket);
+assert.strictEqual(NodeHttpMessageEvent, MessageEvent);