public async Task Test_MultiplyHorizontalAndDepthPosition(string file, int?expectedValue = null) { // Arrange var textLines = await File.ReadAllLinesAsync(file); var puzzleInput = textLines .Where(line => !string.IsNullOrWhiteSpace(line)) .ToList(); var divePlanner = new Dive(puzzleInput); // Act var calculation = divePlanner.MultiplyHorizontalAndDepthPosition(); // Assert Assert.IsTrue(calculation > 0); Debug.WriteLine(calculation); if (expectedValue.HasValue) { Assert.AreEqual(expectedValue, calculation); } }