Mocking Behavior

Syntax#

mock.Setup(expression).Returns(value) //Whenever called the method in the expression will return value

Parameters#

Parameter	Details
expression	Lambda expression that specifies the method invocation.
## No-Argument method mocking

interface Mockable {
    bool DoSomething();
}

var mock = new Mock<Mockable>();
mock.Setup(x => x.DoSomething()).Returns(true);

var result = mock.Object.DoSomething(); //true

Mocking void methods to confirm what they return

var logRepository = new Mock<ILogRepository>();
logRepository.Setup(x => x.Write(It.IsAny<Exception>(), It.IsAny<string>(), It.IsAny<string>(), It.IsAny<string>(), It.IsAny<string>(), It.IsAny<string>()))
  .Verifiable();

In this case, we are using the Verifiable to ensure that it runs.

We could also use a callback here:

logRepository.Setup(x => x.Write(It.IsAny<Exception>(), It.IsAny<string>(), It.IsAny<string>(), It.IsAny<string>(), It.IsAny<string>(), It.IsAny<string>()))
     .Callback<Exception, string, string, string, string, string>((ex, caller, user, machine, source, message) => { Console.WriteLine(message); });

this would log the output from the method to standard output on the console (many testing frameworks let you capture that output into their runner)

Mocking protected members

To mock a protected member you must first include the following at the top of your test fixture:

using Moq.Protected;

You then call Protected() on your mock, after which you can use the generic Setup<> with the return type of your method.

var mock = new Mock<MyClass>();
mock.Protected()
     .Setup<int>("MyProtectedGetIntMethod")
     .Returns(1);

If the method returns void then use the non-generic Setup().