c# - 在NUnit中，如何指示“DataPoint”仅适用于一个理论？

在NUnit中，如果在同一个Datapoint(s)Attribute类中存在多个理论，是否有任何方法表明仅将TestFixture应用于一种理论？

我问的原因是，我通常遵循单元测试约定，其中测试类（CUT）的所有方法都由多个[Test]方法测试，这些方法被卷成一个
单一测试夹具类，现在正尝试从参数化测试转向[Theory]。

还是我应该继续将参数化测试的Values / Range / Random属性用于此类测试？

例如下面，我要确保对用于加法和除法的理论使用不同的数据点：

// C.U.T.
public class BadMaths
{
    public int BadAdd(int x, int y) { return x + y - 1; }
    public int Divide(int x, int y) { return x / y; }
}

[TestFixture]
public class BadMathsTest
{
    // Ideally I want 2 x different datapoints - one for Add, and a different one for divide
    [Datapoints]
    private Tuple<int, int>[] _points = new Tuple<int, int>[]
        {
           new Tuple<int, int>(20, 10),
           new Tuple<int, int>(-10, 0),
        };

    [Theory]
    public void AddTheory(Tuple<int, int> point)
    {
        Assume.That((long)point.Item1 + (long)point.Item2 < (long)int.MaxValue);
        Assert.That(point.Item1 + point.Item2, Is.EqualTo(new BadMaths().BadAdd(point.Item1, point.Item2)));
    }

    [Theory]
    public void DivideTheory(Tuple<int, int> point)
    {
        Assume.That(point.Item2 != 0); // Seems the best I can do - test is inconclusive
        Assert.That(point.Item1 / point.Item2, Is.EqualTo(new BadMaths().Divide(point.Item1, point.Item2)));
    }

}

编辑

上面给出的示例不是Theory用法的一个很好的示例-它更适合TestCaseSource，并且使用新的Roslyn nameof运算符，源中既不需要[DataPoints]也不需要[UsedImplicitly]属性数据。

    [TestCaseSource(nameof(_points)]
    public void EnsureAddPoints(Tuple<int, int> point)
    { ....

最佳答案

我不相信有任何直接的方法可以要求NUnit对不同的理论使用相同类型的不同数据点。但是，有两种可能的解决方法：

第一种是对需要不同数据点值的测试使用不同的TextFixture类：

[TestFixture]
public class BadMathsAdditionTest
{
    // Ideally I want 2 x different datapoints - one for Add, and a different one for divide
    [Datapoints]
    private Tuple<int, int>[] _points = new Tuple<int, int>[]
    {
       new Tuple<int, int>(20, 10),
       new Tuple<int, int>(-10, 0),
    };

    // add tests that use these datapoints
    [Theory]
    public void AddTheory(Tuple<int, int> point)
    {
        Assume.That((long)point.Item1 + (long)point.Item2 < (long)int.MaxValue);
        Assert.That(point.Item1 + point.Item2, Is.EqualTo(new BadMaths().BadAdd(point.Item1, point.Item2)));
    }

}

[TestFixture]
public class BadMathsDivisionTest
{

    // Ideally I want 2 x different datapoints - one for Add, and a different one for divide
    [Datapoints]
    private Tuple<int, int>[] _points = new Tuple<int, int>[]
    {
       new Tuple<int, int>(20, 10),
    };

    // add test that use these datapoints

}

第二种方法需要更多的工作，但是可以说，提供了更具可读性的代码是将每个数据点集包装在不同的结构中，如下所示：

// C.U.T.
public class BadMaths
{
    public int BadAdd(int x, int y) { return x + y - 1; }
    public int Divide(int x, int y) { return x / y; }
}

[TestFixture]
public class BadMathsTest
{

    public struct AdditionData
    {
        public int First { get; set; }
        public int Second { get; set; }
    }
    [Datapoints]
    private AdditionData[] _points = new AdditionData[]
    {
        new AdditionData{First=20, Second=10},
        new AdditionData{First=-10, Second=0}
    };


    public struct DivisionData
    {
        public int First { get; set; }
        public int Second { get; set; }
    }

    [Datapoints]
    private DivisionData[] _points2 = new DivisionData[]
    {
        new DivisionData{First=20, Second=10},
    };

    [Theory]
    public void AddTheory(AdditionData point)
    {
        Assume.That((long)point.First + (long)point.Second < (long)int.MaxValue);
        Assert.That(point.First + point.Second, Is.EqualTo(new BadMaths().BadAdd(point.First, point.Second)));
    }

    [Theory]
    public void DivideTheory(DivisionData point)
    {
        Assume.That(point.Second != 0); // Actually you probably want to keep this condition anyway. Second==0 would be a separate test
        Assert.That(point.First / point.Second, Is.EqualTo(new BadMaths().Divide(point.First, point.Second)));
    }

}