Narwhals Poke Mammals

    This package has been deprecated

    Author message:

    Please upgrade to 1.0 (@mockyeah/server, @mockyeah/fetch, etc.) - see


    0.8.3 • Public • Published

    ‼️ This package has been renamed to mockyeah

    Install latest:

    $ npm install mockyeah --save-dev

    Latest documentation and repository:

    The documentation below is relevant to mockyeah version v0.8.x, which is old and crusty. Installing the latest above is advised.

    Mock Yeah Build Status

    "An invaluable service mocking platform built on Express."

    Testing is difficult when you don't have control of your data. This project puts you in complete control, enabling you to implement real mock web services with ease. Real mock services means you have control of response payloads, HTTP Status Codes, response latency, and more.

    Have a requirement to implement specific behavior when a service is slow to respond or a server returns an unexpected status code? No problem! This platform makes developing for such requirements easy.


    $ npm install mock-yeah --save-dev


    Introductory tutorial

    1. Create an example project and initialized with NPM
    $ mkdir example-app && cd example-app
    $ npm init # all defaults will be fine 
    1. Install mock-yeah
    $ npm install mock-yeah --save-dev
    1. Create script file and add the source below
    $ touch index.js
    const mockyeah = require('mock-yeah');
    mockyeah.get('/hello-world', { text: 'Hello World' });
    1. Run the script file with Node
    $ node index.js
    1. Open http://localhost:4001/hello-world

    2. Profit. You should see "Hello World" returned from your mock server.

    Testing example

    const request = require('supertest')('http://localhost:4041');
    const mockyeah = require('mock-yeah');
    describe('Wondrous service', () => {
      // remove service mocks after each test
      afterEach(() => mockyeah.reset());
      it('should create a mock service that returns an internal error', (done) => {
        // create failing service mock
        mockyeah.get('/wondrous', { status: 500 });
        // assert service mock is working
          .expect(500, done);
      it('should create a mock service that returns JSON', (done) => {
        // create service mock that returns json data
        mockyeah.get('/wondrous', { json: { foo: 'bar' } });
        // assert service mock is working
          .expect(200, { foo: 'bar' }, done);

    Package Dependencies

    • Mock Yeah was built and tested with Node v4.2.3
    • Mocha


    Mock Service Creation API

    mockyeah.get(path, options)
    mockyeah.put(path, options), options)
    mockyeah.delete(path, options

    Each of the methods above create a mock service with a HTTP verb matching its respective method name.



    Path to which to respond. Fully supports all Express path matching options.


    Response options informing Mock Yeah how to respond to matching requests. Supported options:

    • filePath (String; optional) - File with contents to include in response body. Assumes response Content-Type of file type.
    • fixture (String; optional) - Fixture file with contents to include in response body. Assumes response Content-Type of file type.
    • headers (Object; optional) - Header key value pairs to include in response.
    • html (String; optional) - HTML to include in response body. Assumes response Content-Type of text/html.
    • json (Object; optional) - JSON to include in response body. Assumes response Content-Type of application/json.
    • latency (Number/Milliseconds; optional) - Used to control the response timing of a response.
    • text (String; optional) - Text to include in response body. Assumes response Content-Type of text/plain.
    • type (String; optional) - Content-Type HTTP header to return with response. Proxies option to Express response method res.type(type); more info here:
    • status (String; optional; default: 200) - HTTP response status code.

    Note, only one of the following is permitted per service: filePath, fixture, html, json, or text.

    Mock Service Management Methods


    Resets all existing mock services. Useful on test teardown.


    Shuts down the Mock Yeah Express server. Useful if running Mock Yeah with a file watcher. Mock Yeah attempts to start a new instance of Express each test iteration. After all tests run, mockyeah.close() should be called to shutdown Mock Yeah's Express server. Failing to do so will result in EADDRINUSE exceptions. This is due to Mock Yeah attempting to start a server on a port occupied by a server it started previously.


    Getting started

    Installing project and dependencies

    # download project 
    $ git clone
    cd mock-yeah
    # install proper Node version 
    $ nvm install v4.2.3
    $ nvm use
    # install mocha 
    $ npm install -g mocha
    # if tests pass, you're good to go 
    $ npm test


    npm i mock-yeah

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