如何验证Moq是否已调用方法？

Question

I'm trying to validate that SetFirefoxOptions() is called when I call GetFirefoxDriver() . But for whatever reason, Moq keeps telling me that it wasn't called. What am I doing wrong?

Here's my test:

[TestMethod]
public void ShouldSetFirefoxOptions()
{
    var stubCapabilities = new Mock<SauceCaps>().Object;
    var mockManager = new Mock<DriverManager>();
    mockManager.Setup(
        m => m.GetFirefoxDriver(stubCapabilities)).
        Returns(It.IsAny<IWebDriver>());

    mockManager.Verify(
        m => m.SetFirefoxOptions(stubCapabilities));
}

DriverManager.cs:

public class DriverManager : IDriverManager
{
    public virtual Dictionary<string, object> SauceOptions { get; private set; }    

    public DriverManager()
    {
    }

    public virtual IWebDriver GetFirefoxDriver(SauceCaps sauceCaps)
    {
        var browserOptions = SetFirefoxOptions(sauceCaps);

        return new RemoteWebDriver(new Uri("https://ondemand.saucelabs.com/wd/hub"),
            browserOptions.ToCapabilities(), TimeSpan.FromSeconds(600));
    }

    public virtual FirefoxOptions SetFirefoxOptions(SauceCaps sauceCaps)
    {
        return new FirefoxOptions
        {
            BrowserVersion = sauceCaps.BrowserVersion, 
            PlatformName = sauceCaps.Os
        };
    }
}

Answer 1

The problem with your code is that it is unclear what is your System Under Test . You are mocking and testing the same class at the same time. Although it is technicaly possible using moq (using CallBase) it is in principle wrong approach.

The one possibility is to extract SetFirefoxOptions into separate interface and inject it into the DriverManager , eg

public interface IFirefoxOptionCreator
{
    FirefoxOptions SetFirefoxOptions(SauceCaps sauceCaps);
}

public DeviceManager(IFirefoxOptionCreator optionCreator)
{
    _optionCreator = optionCreator;
}

public virtual IWebDriver GetFirefoxDriver(SauceCaps sauceCaps)
{
    var browserOptions = _optionCreator.SetFirefoxOptions(sauceCaps);

    return new RemoteWebDriver(new Uri("https://ondemand.saucelabs.com/wd/hub"),
        browserOptions.ToCapabilities(), TimeSpan.FromSeconds(600));
}

then you could easily verify is interface method was called within your unit tests:

[TestMethod]
public void ShouldSetFirefoxOptions()
{
    // Arrange
    var stubCapabilities = new Mock<SauceCaps>().Object;    
    var optionCreatorMock = new Mock<IFirefoxOptionCreator>();
    optionCreatorMock.Setup(m => m.SetFirefoxOptions(It.IsAny<SauceCaps>()))
                     .Returns(new FirefoxOptions());
    var sut = new DriverManager();    

    // Act
    _ = sut.GetFirefoxDriver(stubCapabilities);

    // Assert
    optionCreatorMock.Verify(m => m.SetFirefoxOptions(stubCapabilities));
}