               _.each response.data, (item) =>
                 @Data.updateEntry item, @matchingCriteria(item)
             return response
+          # Test failure callback by manipulating return value
+          onFail: (response) ->
+            response.data = errorCheck
+            return response
 
+    it "should enable incremental updates", (done) ->
       messages = Messages.all()
       messages.$promise
       .then ->

        done new Error JSON.stringify err

      tick()


      tick()

  describe "with bound callbacks", ->
    Messages = null

    early = 20131220
    okay  = 20131222
    late  = 20131224

    errorCheck = "It failed."

    # Mock Server on `/messages`
    beforeEach inject ($httpBackend) ->
      id = 0
