Question

I have a controller which relies on a service built through ngResource. I am having trouble testing this(although both appear to work like a charm in the actual application). The following is the (sanitized) Controller

MyApp.Controller.MyCarsController = (scope, http, typeService) ->
  if scope.context==undefined
    scope.ferrari_or_porshe =""
    scope.id = ""
  else if scope.context=="ferrari"
    scope.country_or_pi ="Ferrari"
  else if scope.context=="porshe"
    scope.country_or_pi ="Porshe"

  typeService.index
    ferrari_or_porshe: scope.ferrari_or_porshe
    id: scope.id
  , (response) ->
    scope.type = response
    scope.loading = false

MyApp.Controller.MyCarsController.$inject = ['$scope', '$http', 'Type']

And this is the Service:

MyApp.MyModule.factory 'Type', ['$resource', ($resource) ->
  TypeResource = $resource("/api/types/:ferrari_or_porshe/:id", {},
    index:
      method: "GET"
      isArray: true
  )
  return TypeResource
]

Finally, some test code:

describe 'MyApp.Controller.MyCarsController', ->
  beforeEach module('MyModule')
  beforeEach inject ($rootScope, $http, $controller, Type) ->
    @scope = $rootScope.$new()
    @typeService = Type
    @scope.context = undefined
    $controller 'MyApp.Controller.MyCarsController', $scope: @scope

  describe '#home-page', ->

    it 'contains a list of types', ->
      expect(@scope.types.length).toBeGreaterThan 0

    it "sets instance variables correctly", ->
      expect(@scope.ferrari_or_porshe).toBe ""
      expect(@scope.id).toBe ""

Which fails with:

  No more request expected in helpers/angular-mocks.js on line 889
  TypeError: 'undefined' is not an object (evaluating 'this.scope.types.length') in controllers/my_cars_controller_spec.js

By judicious application of console.logs, I have discovered that the issue is that the final callback on response is never reached. TypeResource comes back as [Function].

My questions is:

How do I drive the Jasmine Tests to correctly enter the Service and fetch a response? And is there any way to create direct Unit Tests for Services?

Any and all help is appreciated

Answer 1

The Solution is as follows: for the Service, use $httpBackend which is bundled as part of ngMock:

http://code.google.com/p/google-drive-sdk-samples/source/browse/ruby/app/lib/angular-1.0.0/angular-mocks-1.0.0.js?r=c43c943e32be395b7abca8150deb301d3cbc0dbe

Use this to mock the Rest responses. Since in my case I only cared about verifying that a GET request goes out:

 describe 'Type', ->
   describe '#index', ->
     beforeEach module('MyModule')
     beforeEach inject(($httpBackend) ->
       $httpBackend.whenGET('/api/types/ferrari/1').respond([])
     )

     it 'for a ferrari scope', inject((Type) ->
       ferrari_or_porsche = 'ferrari'
       id = '1'
       expect( Type.index('ferrari_or_porsche': ferrari_or_porsche, 'id': id) ).toEqual([ ])
     )

And then for the controller, mock the service using jasmine spies and use jasmine.any(Function) to warn of the callback.

 describe 'MyApp.Controller.MyCarsController', ->
   beforeEach module('myModule')
   beforeEach inject ($rootScope, $http, $controller, Type) ->
     @scope = $rootScope.$new()
     @typeService = Type
     @scope.context = undefined
     spyOn(@typeService, 'index')

   describe '#home-page', ->
     beforeEach inject ($controller) ->
       $controller 'MyApp.Controller.MyCarsController', $scope: @scope
     it 'contains a list of types', ->
       expect(@typeService.index).toHaveBeenCalledWith({ ferrari_or_porsche : '', id : '' }, jasmine.any(Function))

     it "sets instance variables correctly", ->
       expect(@scope.ferrari_or_porsche).toBe ""
       expect(@scope.id).toBe ""

Note: I make no claims as to the “canonicalness” of this solution. But it works.
Note: The API endpoints are of course tested extensively elsewhere.