public void ReturnSuccessMessageIfItIsNight() { //Arrange var jungle = new Jungle(); jungle.IsDay = false; //Setup var abilityMock = new Mock <IAbility>(); var heroMock = new Mock <IHero>(); var abilities = new List <IAbility>(); abilities.Add(abilityMock.Object); heroMock .SetupGet(hero => hero.Abilities) .Returns(abilities); heroMock .SetupGet(hero => hero.Name) .Returns("Gosho"); string result = jungle.ContinuousEffect(heroMock.Object); Assert.AreEqual("Gosho's damaging abilities power decreased by 2", result); }