如何使用 [SetUp] 方法安排单元测试。参数呢？

Question

public class CoffeeStrengthEstimator
{
    /// <summary>
    ///     Estimates the strength of the coffee (how many beans to use) depending on the button pressed
    /// </summary>
    /// <param name="buttonPressed"> The numeral position of the button pressed</param>
    /// <returns>An enum value indicating the estimated coffee strength</returns>
    public CoffeeStrength EstimateCoffeeStrength(int buttonPressed)
    {
        if (buttonPressed == 1)
        {
            return CoffeeStrength.Light;
        }
        else if (buttonPressed == 2)
        {
            return CoffeeStrength.Medium;
        }
        else if (buttonPressed == 3)
        {
            return CoffeeStrength.Strong;
        }
        else
        {
            throw new ArgumentException ("Invalid Button press, please try again");
        }
    }
}

public enum CoffeeStrength
{
    Light,
    Medium,
    Strong
}

===> 写个单元测试来测试上面的方法可以吗；并使用仅采用 2 个参数的方法创建 CoffeeMaker 类的新对象和 Coffee 类的对象？

Answer 1

不清楚你在问什么，但我假设你在问如何测试CoffeeStrengthEstimator（使用 NUnit，基于标题中的Setup）。

SetUp 方法在测试类中的每个测试方法之前运行，因此用于设置每个方法所需的公共代码 - 这可以为被测系统的任何依赖项提供存根/伪造/模拟 需要，也可能需要实例化一个被测系统的实例。

可以对测试方法进行参数化以接收不同的参数。

综上所述，CoffeeStrengthEstimator 的测试类可能如下所示

[TestFixture]
public class CoffeeStrengthEstimatorTests
{
    private CoffeeStrengthEstimator _estimator;

    [SetUp]
    public void SetUp()
    {
        // common Arrange
        _estimator = new CoffeeStrengthEstimator();
    }

    [Test]
    [TestCase(1, CoffeeStrength.Light)]
    [TestCase(2, CoffeeStrength.Medium)]
    [TestCase(3, CoffeeStrength.Strong)]
    public void EstimateCoffeeStrength_Returns_Expected_CoffeeStrength_For_Button_Pressed_1_2_or_3(int buttonPressed,
        CoffeeStrength expectedCoffeeStrength)
    {
        // Act
        var coffeeStrength = _estimator.EstimateCoffeeStrength(buttonPressed);

        // Assert
        Assert.AreEqual(expectedCoffeeStrength, coffeeStrength);
    }

    [Test]
    [TestCase(-1)]
    [TestCase(0)]
    [TestCase(4)]
    public void EstimateCoffeeStrength_Throws_ArgumentException_When_Button_Pressed_Not_1_2_or_3(int buttonPressed)
    {
        // Act and Assert
        Assert.Throws<ArgumentException>(() => _estimator.EstimateCoffeeStrength(buttonPressed));
    }
}