How can I use NSubstitute for mocking in my tests?

How can I use NSubstitute for mocking in my tests?

NSubstitute is a friendly mocking framework for .NET. You can create substitutes for your interfaces easily. Just use the Substitute.For<T>() method.

Can you show me a simple example?

Sure! Here's a basic example:

public interface IService {
    string GetData();
}

var service = Substitute.For<IService>();
service.GetData().Returns("Hello, World!");

Console.WriteLine(service.GetData()); // Outputs: Hello, World!

What if I want to verify that a method was called?

You can use the Received() method to verify calls. For example:

service.GetData();
service.Received().GetData(); // Verifies that GetData was called.

Are there any limitations I should be aware of?

Yes, NSubstitute works best with interfaces and virtual methods. It won't mock sealed classes or static methods.