mock.md

Unit Testing AngularJS using Mocks

Because AngularJS removes hard-coded dependencies via injection it's possible to change them at run-time and replace them with mocks. Mocks are a great way to isolate the code under test from code it integrates with.

How to use mocks

Using mocks in AngularJS is as easy as providing them. Note that this must be done before the code under test is injected. Order matters:

1. First provide your mocks to override the real implementation.
2. Then inject the mock with the rest of your code under test.
3. Finally assert that the code under test is interacting with the mock correctly.

Controller Testing Patterns has a full example of providing and injecting a mock then asserting its use against an example application.

####Examples

# CoffeeScript
beforeEach ->
  # Provide any mocks needed before each test
  module ($provide) ->
    $provide.value 'Name', new MockName()
    # Make sure CoffeeScript doesn't return anything
    null
    
  # ...

// JavaScript
beforeEach(function () {
  // Provide any mocks needed before each test
  module(function ($provide) {
    $provide.value('Name', new MockName());
  });
  
  // ...
});

Mocks allow you to unit test you are interacting with a dependency correctly. They enable you to control the context and answer questions such as:

Is my code...

• calling a dependency method when it should?
• passing the correct value(s) to that method?
• handling dependency errors?
• cleaning up properly afterward?