为什么我的一些单元测试 运行 多次？

Question

当我使用 Visual Studio 的内置测试引擎 运行 我的解决方案中的所有单元测试时，我会看到一些测试 运行 多次，而其他人只有 运行 一次：

Test Result Window

看来，如果同一个文件中有多个 TestClass，事情就会变得混乱。在这个文件中，例如：

[TestClass]
public class AerationEngineTests
{
    protected IAerationEngine aerationEngine;
    protected AerationPackage aerationPackage;
    protected BinPackage bin;

    [TestInitialize]
    public void TestInitialize()
    {
        aerationEngine = new AerationEngine();
        aerationPackage = new AerationPackage();
        bin = new BinPackage();
        bin.Children.Add(new Shell {ShellDiameter = 75, RingCount = 15, RingHeight = RingHeights.RingHeight32});
    }

    [TestMethod]
    public void ShouldCalculateFloorArea()
    {
        // Arrange


        // Act
        var floorArea = aerationEngine.CalculateFloorArea(aerationPackage, bin);

        // Assert
        floorArea.ShouldBeInRange(4417.86, 4417.87);
    }

    [TestMethod]
    public void ShouldCalculateBinCapacity()
    {
        // Arrange
        aerationPackage.FillType = FillTypes.Peaked;
        var grainDepth = aerationEngine.CalculateGrainDepth(aerationPackage, bin);
        var floorArea = aerationEngine.CalculateFloorArea(aerationPackage, bin);
        var calculations = new FanCalculations {GrainDepth = grainDepth, FloorArea = floorArea};

        // Act
        var binCapacity = aerationEngine.CalculateMaxBinCapacity(calculations);

        // Assert
        binCapacity.ShouldBeInRange(175525.88, 175525.9);
    }

    [TestMethod]
    public void ShouldCalculateTargetAirFlow()
    {
        // Arrange
        aerationPackage.FillType = FillTypes.Peaked;
        aerationPackage.DesiredAirFlow = AirFlowRates.AirFlowOne4th;
        var grainDepth = aerationEngine.CalculateGrainDepth(aerationPackage, bin);
        var floorArea = aerationEngine.CalculateFloorArea(aerationPackage, bin);
        var calculations = new FanCalculations {GrainDepth = grainDepth, FloorArea = floorArea};
        var binCapacity = aerationEngine.CalculateMaxBinCapacity(calculations);
        calculations.MaxBinCapacity = binCapacity;

        // Act
        var airflow = aerationEngine.CalculateTargetAirflow(aerationPackage, calculations);

        // Assert
        airflow.ShouldBeInRange(43881.46, 43881.48);
    }

    [TestMethod]
    public void ShouldCalculateTargetAirFlowPerFan()
    {
        // Arrange
        aerationPackage.FillType = FillTypes.Peaked;
        aerationPackage.DesiredAirFlow = AirFlowRates.AirFlowOne4th;
        aerationPackage.FanCount = 4;
        var grainDepth = aerationEngine.CalculateGrainDepth(aerationPackage, bin);
        var floorArea = aerationEngine.CalculateFloorArea(aerationPackage, bin);
        var calculations = new FanCalculations {GrainDepth = grainDepth, FloorArea = floorArea};
        var binCapacity = aerationEngine.CalculateMaxBinCapacity(calculations);
        calculations.MaxBinCapacity = binCapacity;
        var airflow = aerationEngine.CalculateTargetAirflow(aerationPackage, calculations);
        calculations.TargetAirFlow = airflow;
        // Act
        var flowPerFan = aerationEngine.CalculateTargetAirflowPerFan(aerationPackage, calculations);

        // Assert
        flowPerFan.ShouldBeInRange(10970.3, 10970.4);
    }

    [TestMethod]
    public void ShouldCalculateFloorPressure()
    {
        // Arrange

        // Act
        var floorPressure = aerationEngine.CalculateFloorPressure(aerationPackage, bin);

        // Assert
        floorPressure.ShouldBeInRange(1943.0, 1945.0);
    }

    [TestMethod]
    public void ShouldCalculateTrenchWidth()
    {
        // Arrange
        aerationPackage.FillType = FillTypes.Peaked;
        aerationPackage.DesiredAirFlow = AirFlowRates.AirFlowOne4th;
        aerationPackage.FanCount = 4;
        var grainDepth = aerationEngine.CalculateGrainDepth(aerationPackage, bin);
        var floorArea = aerationEngine.CalculateFloorArea(aerationPackage, bin);
        var calculations = new FanCalculations {GrainDepth = grainDepth, FloorArea = floorArea};
        var binCapacity = aerationEngine.CalculateMaxBinCapacity(calculations);
        calculations.MaxBinCapacity = binCapacity;
        var airflow = aerationEngine.CalculateTargetAirflow(aerationPackage, calculations);
        calculations.TargetAirFlow = airflow;
        var flowPerFan = aerationEngine.CalculateTargetAirflowPerFan(aerationPackage, calculations);
        calculations.TargetAirFlowPerFan = flowPerFan;

        // Act
        var trenchWidth = aerationEngine.CalculateTrenchWidth(calculations);

        // Assert
        trenchWidth.ShouldBe(72);
    }
}

[TestClass]
public class CalculateGrainDepthMethod : AerationEngineTests
{
    [TestInitialize]
    public new void TestInitialize()
    {
        base.TestInitialize();
    }

    [TestMethod]
    public void ShouldCalculateLevelFillHeight()
    {
        // Arrange
        aerationPackage.FillType = FillTypes.Level;

        // Act
        var grainDepth = aerationEngine.CalculateGrainDepth(aerationPackage, bin);

        // Assert
        grainDepth.ShouldBe(40.0);
    }

    [TestMethod]
    public void ShouldCalculatePeakedFillHeight()
    {
        // Arrange
        aerationPackage.FillType = FillTypes.Peaked;

        // Act
        var grainDepth = aerationEngine.CalculateGrainDepth(aerationPackage, bin);

        // Assert
        grainDepth.ShouldBeInRange(46.64, 46.66);
    }
}

CalculateGrainDepthMethod 中的测试获得 运行 一次，但其余测试方法获得 运行 两次，它们被分组在 CalculateGrainDepthMethod 下。查看此图片（使用 ReSharper 的工具）：

ReSharper Test result window

似乎没有两个测试引擎同时 运行ning，但也许有？或者也许我只是错误地构建了测试本身？有谁知道为什么这些测试会 运行 不止一次，为什么它们会被归入 类 而它们不属于？

Answer 1

您正在继承 class CalculateGrainDepthMethod 继承自 AerationEngineTests。因为 class AerationEngineTests 中的这个测试执行了两次。

[TestClass]
public class CalculateGrainDepthMethod : AerationEngineTests
{

要么在 class CalculateGrainDepthMethod 中包含依赖项，要么创建一个测试助手来初始化这些值并在你的测试中使用它 classes.