public async void GetBenefitDetails_ShouldCallService() { // Arrange _mockService.Setup(_ => _.GetBenefitDetails(It.IsAny <string>(), It.IsAny <string>(), It.IsAny <string>())) .ReturnsAsync(It.IsAny <BenefitsClaim>()); // Act var result = await _controller.GetBenefitDetails(It.IsAny <string>(), It.IsAny <string>(), It.IsAny <string>()); // Assert _mockService.Verify(_ => _.GetBenefitDetails(It.IsAny <string>(), It.IsAny <string>(), It.IsAny <string>()), Times.Once); var actionResult = Assert.IsType <OkObjectResult>(result); Assert.Equal(200, actionResult.StatusCode); }