playwright-easy-network-stub

May 19, 2026 ยท View on GitHub

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playwright-easy-network-stub

An easy class to mock a lot of network requests in playwright.

See also ๐Ÿ”ฌ

The base class of this package is: https://github.com/LoaderB0T/easy-network-stub

Motivation ๐Ÿ’ฅ

When running tests in playwright, sometimes you want to mock all network requests. Especially when running tests in a CI environment. This package provides an easy and type-safe way to mock network requests for a whole API.

Features ๐Ÿ”ฅ

โœ… Easy to setup and use

โœ… Type safe url and query parameters

โœ… Add your own parameter matchers

โœ… Works asynchronously (Promise based)

โœ… Supports failing of stubbed requests

โœ… Supports EventSource & ndjson

โœ… Supports WebSockets

โœ… No production dependencies (You need to have playwright installed, of course)

โœ… ESM exports

The primary use case for this package is to create a mock server for your tests so that they do not need real network requests.

Built With ๐Ÿ”ง

Usage Example ๐Ÿš€

const posts = [0, 1, 2, 3, 4, 5].map(x => ({ postId: x, text: `test${x}` }));

const blogStub = new PlaywrightEasyNetworkStub(/MyServer\/api\/Blog/);

blogStub.init();

blogStub.stub('GET', 'posts', () => {
  return posts;
});

// Match Example: GET: /MyServer/api/Blog/posts/123
blogStub.stub('GET', 'posts/{id:number}', ({ params }) => {
  return posts.find(x => x.postId === params.id);
});

// Match Example: POST: /MyServer/api/post
blogStub.stub('POST', 'posts', ({ body, params }) => {
  posts.push({ postId: body.postId, text: body.text });
});

// Match Example: POST: /MyServer/api/Blog/test/true?query=myValue&secondQuery=myOtherValue
// Note: The order of the query parameters is not important
blogStub.stub('POST', 'test/{something:boolean}?{query:string}&{secondQuery:number}', ({ body, params }) => {
  console.log(params.something);
  console.log(params.query);
  console.log(params.secondQuery);
  console.log(body);
});

// Here we use the stub2<>() method to create a stub with a typed body
blogStub.stub2<MyRequest>()('POST', 'test', ({ body }) => {
  console.log(body.myValue);
});

// You can mark query params as optional with a '?'
// Match Example: GET: /MyServer/api/Blog/test
// Match Example: GET: /MyServer/api/Blog/test?refresh=true
blogStub.stub('GET', 'test?{refresh?:boolean}', ({ body, params }) => {
  if (params.refresh) {
    console.log('Refreshing');
  }
  console.log(body.myValue);
});

// You can mark query params as arrays with a '[]'
// Match Example: GET: /MyServer/api/Blog/test?props=1
// Match Example: GET: /MyServer/api/Blog/test?props=1&props=2
blogStub.stub('GET', 'test?{props:number[]}', ({ params }) => {
  params.props.forEach(x => console.log(x));
});


// You can remove a stub with its handle or all stubs at once
const handle = blogStub.stub('GET', 'test?{props:number[]}', ({ params }) => {
  params.props.forEach(x => console.log(x));
});
handle.unregister(); // remove this stub
// Or:

blogStub.unregisterAll(); // remove all stubs

Strongly typed api parameters

You can add types to parameters and they will be parsed. Out of box 'string', 'number' and 'boolean' are supported. You can add your own types and parsers though.

Stub streams

import { StreamResponseHandler } from 'easy-network-stub/stream';

const srh = new StreamResponseHandler();
blogStub.stub('POST', 'test', () => srh);

srh.send('Hello');
srh.send('World');
srh.close();

Execution order

When two registered stubs match a request URL, the latest stub (registered last) is used to respond.

Contributing ๐Ÿง‘๐Ÿปโ€๐Ÿ’ป

Contributions are what make the open source community such an amazing place to learn, inspire, and create. Any contributions you make are greatly appreciated.

If you have a suggestion that would make this better, please fork the repo and create a pull request. You can also simply open an issue with the tag "enhancement". Don't forget to give the project a star! Thanks again!

  1. Fork the Project
  2. Create your Feature Branch (git checkout -b feature/AmazingFeature)
  3. Commit your Changes (git commit -m 'Add some AmazingFeature')
  4. Push to the Branch (git push origin feature/AmazingFeature)
  5. Open a Pull Request

License ๐Ÿ”‘

Distributed under the MIT License. See LICENSE.txt for more information.

Contact ๐Ÿ“ง

Janik Schumacher - @LoaderB0T - linkedin

Project Link: https://github.com/LoaderB0T/playwright-easy-network-stub