NSubstitute: A friendly substitute for .NET mocking libraries

//Create: var calculator = Substitute.For<ICalculator>(); //Set a return value: calculator.Add(1, 2).Returns(3); Assert.AreEqual(3, calculator.Add(1, 2)); //Check received calls: calculator.Received().Add(1, Arg.Any<int>()); calculator.DidNotReceive().Add(2, 2); //Raise events calculator.PoweringUp += Raise.Event(); ReceivedCallsException : Expected to receive a call matching: Add(1, 2) Actually r