public void SetNextHandler_UsingType_AddsSequentially() { // Arrange var factoryMock = Substitute.For <IApiHttpHandlerFactory>(); var binding = new ApiHttpRequestHandlerBinding(factoryMock, typeof(ApiHttpRequestHandlerMock)); var handler1 = typeof(ApiHttpRequestHandlerMock.ApiHttpRequestHandlerDifferentType1Mock); var handler2 = typeof(ApiHttpRequestHandlerMock.ApiHttpRequestHandlerDifferentType2Mock); // Act binding.SetNextHandler(handler1); binding.SetNextHandler(handler2); // Assert Assert.NotNull(binding.Next); Assert.NotEqual(handler1, binding.Next.HandlerType); Assert.Equal(handler2, binding.Next.HandlerType); }