Check deferred helper (promises) for Jasmine calls

StellarModuleTest.coffee

###
Stellar Module Test - Assumes jasmine is global
@author: Kaleb Fulgham
@license: MIT
###
define [
    '../specs/helpers/TestHelpers' 
    'modules/StellarModule'
],
(TestHelpers, StellarModule) ->

    describe "StellarModule", ->
        describe "ItemView", ->
            it "should do foo bar baz with view", ->
                itemView = new ItemView()
                promise = itemView.render()

                TestHelpers.checkDeferred promise, ->
                    expect(itemView.$el).toBeDefined();
                    # more expectations

TestHelpers.coffee

###
TestHelpers
@author: Kaleb Fulgham
@license: MIT
###
define [], -> 
    TestHelpers =         
        checkDeferred: (df, callback) ->
            ###
            Wait for the deferred object to finish and execute the callback once done.
            ###
            spy = jasmine.createSpy()
            df.then(spy)
            waitsFor ->
                spy.callCount > 0
            , "Async call never occurred", 1000

            runs -> 
                callback.apply @, spy.mostRecentCall.args if callback

    TestHelpers