Jasmine matcher for Backbone.Event expectations

backbone-jasmine-event-matcher.coffee

# Usage:
# 
# @model.doSomething = ->
#   @other_model.trigger('something_done', 'somearg')
#
# expect(=> @model.doSomething()).toTrigger('something_done', on: @other_model, with: [ 'somearg' ])
# 

beforeEach -> 

  @addMatchers
    toTrigger: (eventName, object) ->
      block  = @actual
      args   = object.with or []
      object = object.on or object
      triggered = false 

      object.on eventName, (actualArgs...) ->
        _(args).each (arg, index) ->
          expect(actualArgs[index]).toEqual(arg)

        triggered = true

      block.apply()
      return triggered