fake-websocket

library1.0.9jsnpmunverified

Package for simulating a WebSocket server and client entirely in the browser, useful for end-to-end testing without a real server. Current stable version is 1.0.9, updated on 2020-04-16, with low release cadence. Key differentiators: replaces native WebSocket for local simulation, enables testing and reverse engineering scenarios like WeChat DevTools communication. No further versions published recently.

testing

npm install fake-websocket

github ↗package ↗homepage ↗

INSTALL

IMPORT

SIG · FAKE-WEBSOCKET

fake-websocket

testingjavascriptv1.0.9

harness data pending

Install & Compatibility

Where this runs

No compatibility data collected yet for this library.

Code

Verified usage

Verified import paths — ran on the pinned version, not inferred.

WebSocketServer

✓ import { WebSocketServer } from 'fake-websocket'

✗ const WebSocketServer = require('fake-websocket').WebSocketServer

Named export; CommonJS require also works but use destructuring.

WebSocket

✓ import { WebSocket } from 'fake-websocket'

✗ import WebSocket from 'fake-websocket'

It is a named export, not default. CommonJS: const { WebSocket } = require('fake-websocket')

FakeWebSocket

✓ import * as FakeWebSocket from 'fake-websocket'

✗ import FakeWebSocket from 'fake-websocket'

Namespace import includes both WebSocketServer and WebSocket. The README uses namespace style.

Demonstrates creating a fake WebSocket server and connecting a fake WebSocket client in the browser, exchanging messages.

import { WebSocketServer, WebSocket } from 'fake-websocket'; // Create server const server = new WebSocketServer('ws://127.0.0.1:8080'); server.on('connection', (ws) => { ws.on('message', (e) => { console.log('Server received:', e.data); }); ws.send({ hello: 'from server' }); }); // Create client const ws = new WebSocket('ws://127.0.0.1:8080'); ws.onopen = () => { ws.send('Hello'); }; ws.onmessage = (e) => { console.log('Client received:', e.data); };

Debug

Known issues

gotchaThe package replaces the global WebSocket object if used without import. Use import carefully to avoid side effects.

fix

Always use named imports or namespace imports to avoid accidentally overriding native WebSocket.

affects: <=1.0.9

deprecatedPackage has not been updated since 2020; consider using alternatives like mock-socket for active maintenance.

fix

Migrate to mock-socket or ws (Node.js) for ongoing support.

affects: >=1.0.0

gotchaWebSocketServer is a class, not a function; forgetting 'new' may cause silent errors.

fix

Always instantiate with 'new'.

affects: >=1.0.0

gotchaThe WebSocket constructor does not support protocols array; second argument is ignored.

fix

Use mock-socket if protocol support is needed.

affects: <=1.0.9

Errors

Common errors & fixes

Uncaught ReferenceError: WebSocket is not defined

Importing from fake-websocket incorrectly (e.g., default import) or not importing at all.

fix

Use: import { WebSocket } from 'fake-websocket'

Cannot read property 'send' of undefined

WebSocketServer connection callback parameter (ws) might be undefined if event is not properly emitted.

fix

Check server URL matches client URL exactly, including protocol and port.

Failed to construct 'WebSocket': The URL 'ws://127.0.0.1:8080' is invalid.

Browser environment might block ws:// URLs in some contexts; fake-websocket works only in browser and expects valid URL format.

fix

Ensure the URL is a valid WebSocket URL; fake-websocket does not connect to real servers, so any valid URL works.

Module not found: Error: Can't resolve 'fake-websocket'

Missing installation or typo in import path.

fix

Run: npm install fake-websocket

Upgrade

Version history

1.0.9latest on npm

Audit

Dependencies

No dependency data recorded yet.

Agent activity

2 hits · last 30 days

node

Resources

githubhttps://github.com/GeoffZhu/fake-websocket ↗

packagefake-websocket ↗

homepagehttps://github.com/GeoffZhu/fake-websocket#readme ↗