fetching the Message on the Dialog box after Mocking the Dialog box using Moq in .net

Question

I am unit testing the Dialog boxes and in the Test cases Dialog box may launch with different messages depending upon the Test case .

Dialog box code :

uiService.ShowMessage(StudioViewName.MainWindow, "No cell selected.", this.resourceManager.GetResourceString(StudioResourceManagerName.StudioResourceManager, "IDC_WinshuttleStudio"), MessageBoxButton.OK, MessageBoxImage.Error);

I mocked it like this :UIServicemock.Setup(u=>u.ShowMessage(It.IsAny<int>(),It.IsAny<string>(),It.IsAny<string>(),It.IsAny<MessageBoxButton>(),It.IsAny<MessageBoxImage>()))

Now I want to check the Message in the dialog box or to verify in unit test cases that the particular Message bearing box is popped up only.

Answer 1

You can use a callback to assert that the values match what you expect.

UIServicemock
    .Setup(u => u.ShowMessage(It.IsAny<int>(), It.IsAny<string>(), It.IsAny<string>(),
        It.IsAny<MessageBoxButton>(), It.IsAny<MessageBoxImage>()))
    .Callback<int, string, string, MessageBoxButton, MessageBoxImage>((window, message, error, button, image) => {
        Assert.That(message, Is.EqualTo("No cell selected"));
        Assert.That(window, Is.EqualTo(StudioViewName.MainWindow));
    });

Or you could use the It matchers that match specific parameters, as follows:

UIServicemock
    .Setup(u => u.ShowMessage(
        It.Is<int>(s => s == StudioViewName.MainWindow),
        It.IsIn<string>("No cell selected"),
        It.IsAny<string>(),
        It.IsAny<MessageBoxButton>(),
        It.IsAny<MessageBoxImage>()));

I generally find the first method more flexible, but it is a bit more verbose.

Answer 2

Use Verify:

string expectedResourceString = /* whatever you expect */;
UIServicemock.Verify(u => u.ShowMessage(StudioViewName.MainWindow, 
                                        "No cell selected",
                                        expectedResourceString,
                                        MessageBoxButton.OK, 
                                        MessageBoxImage.Error));

Much clearer what you're trying to test. If you don't care about a value, us It.IsAny in place of it.