Mocking objects with Moq when constructor has parameters

Question

I have an object I'm trying to mock using moq. The object's constructor has required parameters:

public class CustomerSyncEngine {
    public CustomerSyncEngine(ILoggingProvider loggingProvider, 
                              ICrmProvider crmProvider, 
                              ICacheProvider cacheProvider) { ... }
}

Now I'm trying to create the mock for this object using either moq's v3 "setup" or v4 "Mock.Of" syntax but can't figure this out... everything I'm trying isn't validating. Here's what I have so far, but the last line is giving me a real object, not the mock. The reason I'm doing this is because I have methods on the CustomerSyncEngine I want to verify are being called...

// setup
var mockCrm = Mock.Of<ICrmProvider>(x => x.GetPickLists() == crmPickLists);
var mockCache = Mock.Of<ICacheProvider>(x => x.GetPickLists() == cachePickLists);
var mockLogger = Mock.Of<ILoggingProvider>();

// need to mock the following, not create a real class like this...
var syncEngine = new CustomerSyncEngine(mockLogger, mockCrm, mockCache);

Answer 1

The last line is giving you a real instance because you are using the new keyword, not mocking CustomerSyncEngine.

You should use Mock.Of<CustomerSyncEngine>()

The only problem with Mocking Concrete types is that Moq would need a public default constructor(with no parameters) OR you need to create the Moq with constructor arg specification. http://www.mockobjects.com/2007/04/test-smell-mocking-concrete-classes.html

The best thing to do would be right click on your class and choose Extract interface.

Answer 2

Change the last line to

var syncEngine = new Mock<CustomerSyncEngine>(mockLogger, mockCrm, mockCache).Object;

and it should work