public void ItShouldCallAdderWhenGivenPlusSymbol() { _mockQueryParser.Stub(x => x.Parse(Arg <string> .Is.Anything)).Return(new Calculation("+", 2, 3)); _mockAdder.Expect(x => x.Add(Arg.Is(2), Arg.Is(3))).Return(0); _calculator.Calculate(""); _mockAdder.VerifyAllExpectations(); _mockDivider.VerifyAllExpectations(); _mockMultiplier.VerifyAllExpectations(); _mockSubtractor.VerifyAllExpectations(); }