An example unit test for our save thread method

api-test.js

var nodeunit = require('nodeunit');

exports['API'] = nodeunit.testCase({
  'The show() API method returns a specific thread by title and its replies by threadid': function(test) {
    test.expect(4);
    
    // our mock data
    var posts = [{post: 'test'}, {post: 'test2'}];
    var thread = {_id: '1234', title: 'my thread'};

    // A mock thread that overrides the findOne method, checking the parameters
    // and calling the given callback with our mock thread object.
    var MockThread = {
      findOne: function(params, callback) {
        test.deepEqual(params, {title: thread.title});
        callback(null, thread);
      }
    };

    // A mock post that check if it was called with the right parameters,
    // returns our mock posts.
    var MockPost = {
      find: function(params, callback) {
        test.equal(params.thread, thread._id);
        callback(null, posts);
      }
    };
    
    // Our request parameters.
    var request = {
      params: {
        title: thread.title
      }
    };

    // Finally, our response object in which we test to make sure our
    // controller returns the right results.
    var response = {
      send: function(params) {
        test.equal(params[0].thread, thread);
        test.equal(params[0].posts, posts);
      }
    }

    // Phew. Run it. Note we pass our mock Thread and Post to the API here.
    var api = require('./controllers/api.js')(MockThread, MockPost);
    api.show(request, response);
    test.done();
  }
});