C# 使用自定义比较函数断言

在我的代码中测试一些向量操作时，我必须检查是否与某个公差值相等，因为

浮点值可能不完全匹配

这意味着我的测试断言如下：

Assert.That(somevector.EqualWithinTolerance(new Vec3(0f, 1f, 0f)), Is.True);

Expected: True
But was:  False

Assert.That(somevector, Is.EqualTo(new Vec3(0f, 1f, 0f)).Using(fuzzyVectorComparer));

与此相反：

Assert.That(somevector, Is.EqualTo(new Vec3(0f, 1f, 0f)));

Expected: 0 1 0
But was:  1 0 9,536743E-07

这意味着我的例外情况如下：

Assert.That(somevector.EqualWithinTolerance(new Vec3(0f, 1f, 0f)), Is.True);

Expected: True
But was:  False

Assert.That(somevector, Is.EqualTo(new Vec3(0f, 1f, 0f)).Using(fuzzyVectorComparer));

与此相反：

Assert.That(somevector, Is.EqualTo(new Vec3(0f, 1f, 0f)));

Expected: 0 1 0
But was:  1 0 9,536743E-07

让我们更难理解出了什么问题

如何使用自定义比较函数并仍然获得一个很好的异常？找到了答案。NUnit
EqualConstraint
有一个具有预期名称的方法：
Using

所以我刚刚添加了这个类：

    /// <summary>
    /// Equality comparer with a tolerance equivalent to using the 'EqualWithTolerance' method
    /// 
    /// Note: since it's pretty much impossible to have working hash codes
    /// for a "fuzzy" comparer the GetHashCode method throws an exception.
    /// </summary>
    public class EqualityComparerWithTolerance : IEqualityComparer<Vec3>
    {
        private float tolerance;

        public EqualityComparerWithTolerance(float tolerance = MathFunctions.Epsilon)
        {
            this.tolerance = tolerance;
        }

        public bool Equals(Vec3 v1, Vec3 v2)
        {
            return v1.EqualWithinTolerance(v2, tolerance);
        }

        public int GetHashCode(Vec3 obj)
        {
            throw new NotImplementedException();
        }
    }

打字要多一些，但这是值得的