Verify method of Moq throwing error in ASP.NET MVC unit testing

Question

I am developing an ASP.NET MVC project. In my project I am doing unit testing. I am using Moq to mock my business logics. But I am having a problem with Moq. Especially with mock.Verify method.

This is the action I am testing

[HttpPost]
        public ActionResult Edit(CreateRegionVM model)
        {
            if(ModelState.IsValid)
            {
                Region region = new Region
                {
                    Id = model.Id,
                    Name = model.Name,
                    MmName = model.MmName,
                    Description = model.Description,
                    MmDescription = model.MmDescription,
                    GeoLocation = model.GeoLocation,
                    ImagePath = model.ImagePath
                };
                String imagePath = String.Empty;
                if(model.ImageFile!=null && model.ImageFile.ContentLength>0)
                {
                    imagePath = fileHelper.UploadFile(model.ImageFile, AppConfig.RegionImageDir,null);
                    if(String.IsNullOrEmpty(imagePath))
                    {
                        return new HttpStatusCodeResult(HttpStatusCode.InternalServerError);
                    }
                    else
                    {
                        //create thumb & delete old images - check the image operations
                        fileHelper.CreateThumb(imagePath, AppConfig.RegionImageDir, AppConfig.RegionMediumThumbWidth, AppConfig.RegionMediumThumbHeight, AppConfig.MediumThumbSuffix);
                        fileHelper.CreateThumb(imagePath, AppConfig.RegionImageDir, AppConfig.RegionSmallThumbWidth, AppConfig.RegionSmallThumbHeight, AppConfig.SmallThumbSuffix);

                        fileHelper.DeleteFile(model.ImagePath);
                        fileHelper.DeleteFile(fileHelper.GetImagePath(model.ImagePath, AppConfig.MediumThumbSuffix));
                        fileHelper.DeleteFile(fileHelper.GetImagePath(model.ImagePath, AppConfig.SmallThumbSuffix));
                        model.ImagePath = imagePath;
                    }
                }

                try
                {
                    regionRepo.Update(region);
                    TempData["message"] = "Region successfully edited";
                    TempData["class"] = AppConfig.FlashSuccessClass;
                    return RedirectToAction("Edit", new { id = model.Id });
                }
                catch
                {
                    return new HttpStatusCodeResult(HttpStatusCode.InternalServerError);
                }
            }
            return View("Create",model);
        }

This is my test function

 [TestMethod]
        public void Edited_And_Redirected()
        {
            var postFile = new Mock<HttpPostedFileBase>();
            postFile.Setup(m => m.ContentLength).Returns(1);

            CreateRegionVM model = new CreateRegionVM
            {
                Id = 1,
                Name = "test",
                ImageFile = postFile.Object
            };

            Mock<IRegionRepo> regionMock = new Mock<IRegionRepo>();
            regionMock.Setup(m => m.Update(new Region())).Verifiable();
            Mock<IFileHelper> fileMock = new Mock<IFileHelper>();
            fileMock.Setup(m => m.UploadFile(model.ImageFile, It.IsAny<String>(), null)).Returns("upload_file_path");

            RegionController controller = new RegionController(regionMock.Object, fileMock.Object, 0);
            var unknownView = controller.Edit(model);
            regionMock.Verify();
            Assert.IsInstanceOfType(unknownView, typeof(RedirectToRouteResult), "Not redirected");
        }

As you can see my test method, I am using verify to make sure regionRepo.Update method is called. But it is giving me this error when I run the test.

Moq.MockVerification Exception: The following setups were not matched: IRegionRepo m=>m=>Update()

Why is this error thrown? How does the verify method of moq work?

Answer 1

Take a look at this line:

regionMock.Setup(m => m.Update(new Region())).Verifiable();

It's going to compare the input to new Region(), but most likely whatever you're passing in is not going to be referentially equal to that.

If the Region doesn't matter, try

regionMock.Setup(m => m.Update(It.IsAny<Region>())).Verifiable();