public void ShouldGetTheTotalNumberOfBagsContainedInBag() { var mockData = new List <string>() { "shiny gold bags contain 2 dark red bags.", "dark red bags contain 2 dark orange bags.", "dark orange bags contain 2 dark yellow bags.", "dark yellow bags contain 2 dark green bags.", "dark green bags contain 2 dark blue bags.", "dark blue bags contain 2 dark violet bags.", "dark violet bags contain no other bags.", }; var autoMocker = new AutoMoqer(); _fileReaderMock.Setup(f => f.ReadFileToStringArray(It.IsAny <string>())).Returns(mockData); _solution = new Day7Solution(_fileReaderMock.Object); var number = _solution.GetNumberOfBagsInsideBag("shiny gold") - 1; Assert.AreEqual(number, 126); }