c# - Verify a method call using Moq

Question

I am fairly new to unit testing in C# and learning to use Moq. Below is the class that I am trying to test.

class MyClass
{
    SomeClass someClass;
    public MyClass(SomeClass someClass)
    {
        this.someClass = someClass;     
    }

    public void MyMethod(string method)
    {
        method = "test"
        someClass.DoSomething(method);
    }   
}

class Someclass
{
    public DoSomething(string method)
    {
        // do something...
    }
}

Below is my TestClass:

class MyClassTest
{
    [TestMethod()]
    public void MyMethodTest()
    {
        string action="test";
        Mock<SomeClass> mockSomeClass = new Mock<SomeClass>();
        mockSomeClass.SetUp(a => a.DoSomething(action));
        MyClass myClass = new MyClass(mockSomeClass.Object);
        myClass.MyMethod(action);
        mockSomeClass.Verify(v => v.DoSomething(It.IsAny<string>()));
    }
}

I get the following exception:

Expected invocation on the mock at least once, but was never performed
No setups configured.
No invocations performed..

I just want to verify if the method "MyMethod" is being called or not. Am I missing something?

Answer 1

You're checking the wrong method. Moq requires that you Setup (and then optionally Verify) the method in the dependency class.

You should be doing something more like this:

class MyClassTest
{
    [TestMethod]
    public void MyMethodTest()
    {
        string action = "test";
        Mock<SomeClass> mockSomeClass = new Mock<SomeClass>();

        mockSomeClass.Setup(mock => mock.DoSomething());

        MyClass myClass = new MyClass(mockSomeClass.Object);
        myClass.MyMethod(action);

        // Explicitly verify each expectation...
        mockSomeClass.Verify(mock => mock.DoSomething(), Times.Once());

        // ...or verify everything.
        // mockSomeClass.VerifyAll();
    }
}

In other words, you are verifying that calling MyClass#MyMethod, your class will definitely call SomeClass#DoSomething once in that process. Note that you don't need the Times argument; I was just demonstrating its value.