public void Verify_MapToEntityExtension_CallsMapToEntity() { // Arrange var mockMapper = new Mock <StoryArcWriterMapper>(); mockMapper.Setup(x => x.MapToEntity(It.IsAny <IStoryArcWriterModel>(), It.IsAny <int>())); var mockModel = StoryArcWritersMockingSetup.DoMockingSetupForStoryArcWriterModel(1); StoryArcWriterMapperExtensions.OverrideMapper(mockMapper.Object); // Act mockModel.Object.MapToEntity(); // Assert mockMapper.Verify(x => x.MapToEntity(It.IsAny <IStoryArcWriterModel>(), It.IsAny <int>()), Times.Once); }