public void ReturnBuzzIfNumberIsDivisibleByThreeFive() { var mockedCalculator = new Mock<ICalculator>(); var wordGetter = new WordGetter(mockedCalculator.Object); mockedCalculator.Setup(mc => mc.IsDivisibleByFive(It.IsAny<int>())).Returns(true); var result = wordGetter.GetBuzzIfRequired(7); Assert.AreEqual(result, "Buzz"); }