How can I unit test the m.request model in Mithril?

I am trying to unit test Mithril's model using m.request

DOM-less framework .

For me this test works as an integration test in a browser environment using the browser XMLHttpRequest, but he would like this option to run in isolation.

I'm considering mixing up the XMLHttpRequest response to get it properly initialized m.request

, but I'm not sure where to start. I have a naive XMLHttpRequest implementation banished from a test and looked into the source m.request

, but as a relative JS newbie, it's hard to follow.

Does this mean it makes sense to completely disable m.request

it just to test the transformation, since I trust Mithril is working (and is technically a dependency of the device under test)? This scares me a little as it m.request

has chaining behavior that can be tricky to stub.

I would happily agree with an answer, which usually outlines the steps I need to take to make some progress on this issue and / or some advice on what makes sense to test.

require('chai').should();
require('mithril');

m.deps({ XMLHttpRequest: function() {
  this.open = function() {
  }

  this.setRequestHeader = function() {
  }

  this.send = function() {
  }
}});

var Curriculum = require('../../../app/modules/practice/practice.curriculum');

describe('Curriculum', function() {
  it('can retrieve a list of modules', function(done) {
    Curriculum.modules().then(function(modules) {
      modules.should.deep.equal([
        { name: 'Module 1' },
        { name: 'Module 2' },
        { name: 'Module 3' }
      ]);
      done();
    });
  });
});

      

        
        
        
      

    

Currently running this test s is being mocha

played uselessly with no output or errors.

Source of the device under test, if useful:

module.exports = {
  modules: function() {
    // URL obscured to protect the innocent.
    return m.request({
      method: 'GET',
      url: 'http://working.url'
    }).then(function(objects) {
      var transformed = objects.map(function(object) {
        return { name: object.name };
      });
      return transformed;
    });
  }
};