Example from http://twolfson.com/2015-01-11-testing-with-other-services

.gitignore

data/
node_modules/

index.js

// Load in dependencies
var eightTrack = require('eight-track');
var expect = require('chai').expect;
var FixedServer = require('fixed-server');
var httpUtils = require('request-mocha')(require('request'));

// Create a test server factory with modifying endpoints
var githubEightTrack = eightTrack({
  url: 'https://api.github.com',
  fixtureDir: 'data/github-eight-track'
});
var FixedGithub = new FixedServer({port: 1337});
FixedGithub.addFixtures({
  'GET 200 /repos/uber/eight-track': {
    method: 'get',
    route: '/repos/uber/eight-track',
    // Playback directly with eight-track
    response: githubEightTrack
  },
  'GET 200 /repos/uber/eight-track#no-watchers': {
    method: 'get',
    route: '/repos/uber/eight-track',
    response: function (localReq, localRes) {
      // Forward request via eight-track
      githubEightTrack.forwardRequest(localReq, handleResponse);
      function handleResponse(err, externalRes, externalBody) {
        // If there was an error, throw it
        if (err) {
          throw err;
        }

        // Otherwise, extract the JSON and modify the watchers
        var repoInfo = JSON.parse(externalBody);
        repoInfo.watchers = 0;
        localRes.send(repoInfo);
      }
    }
  }
  // We can add the 500 response from the previous example
  //   for entirely fake data
});

// Start our tests
describe('A GitHub repo', function () {
  describe('is very popular', function () {
    // Launch a FixedServer with real data
    FixedGithub.run(['GET 200 /repos/uber/eight-track']);
    httpUtils.save({
      url: 'http://localhost:1337/repos/uber/eight-track',
      headers: {
        'User-Agent': 'node-request'
      }
    });

    // Make assertions about request
    it('has some stargazers', function () {
      expect(this.err).to.equal(null);
      expect(this.res.statusCode).to.equal(200);
      expect(JSON.parse(this.body).watchers).to.be.at.least(1);
    });
  });

  describe('is very young', function () {
    // Launch a FixedServer hosting with a modified response
    FixedGithub.run(['GET 200 /repos/uber/eight-track#no-watchers']);
    httpUtils.save({
      url: 'http://localhost:1337/repos/uber/eight-track',
      headers: {
        'User-Agent': 'node-request'
      }
    });

    // Make assertions about request
    it('has no watchers', function () {
      expect(this.err).to.equal(null);
      expect(this.res.statusCode).to.equal(200);
      expect(JSON.parse(this.body).watchers).to.equal(0);
    });
  });
});

package.json

{
  "name": "gist-eight-track-article-3",
  "version": "1.0.0",
  "description": "Example from http://twolfson.com/2015-01-11-testing-with-other-services",
  "main": "index.js",
  "author": "Todd Wolfson <todd@twolfson.com> (http://twolfson.com/)",
  "license": "UNLICENSE",
  "scripts": {
    "test": "mocha index.js"
  },
  "dependencies": {
    "chai": "~1.10.0",
    "eight-track": "~2.1.0",
    "fixed-server": "~0.4.0",
    "mocha": "~2.1.0",
    "request": "~2.51.0",
    "request-mocha": "~0.2.0"
  }
}