使用派生类时如何使用 Fluent Assertion Should().BeEquivalentTo() 检查等价性

Question

我在尝试让 Should().BeEquivalentTo() 处理从基类派生的类型并实现集合接口时遇到问题：

public class Entity
{
    public string Id {get; set;}
    public string Name {get; set;}
}

public class Derived : Entity, ICollection<Entity>
{
    private List<Entity> m_Children = new List<Entity>();

    public string Description { get; set; }

    public int Count => ((ICollection<Entity>)m_Children).Count;

    public bool IsReadOnly => ((ICollection<Entity>)m_Children).IsReadOnly;

    public void Add(Entity item)
    {
        ((ICollection<Entity>)m_Children).Add(item);
    }

    public void Clear()
    {
        ((ICollection<Entity>)m_Children).Clear();
    }

    public bool Contains(Entity item)
    {
        return ((ICollection<Entity>)m_Children).Contains(item);
    }

    public void CopyTo(Entity[] array, int arrayIndex)
    {
        ((ICollection<Entity>)m_Children).CopyTo(array, arrayIndex);
    }

    public IEnumerator<Entity> GetEnumerator()
    {
        return ((ICollection<Entity>)m_Children).GetEnumerator();
    }

    public bool Remove(Entity item)
    {
        return ((ICollection<Entity>)m_Children).Remove(item);
    }

    IEnumerator IEnumerable.GetEnumerator()
    {
        return ((ICollection<Entity>)m_Children).GetEnumerator();
    }
}

测试

[TestMethod]
public void EquivalenceTest()
{
    var expected = new Derived
    {
        Id = "123",
        Name = "abc",
        Description = "def"
    };
    var actual = new Derived
    {
        Id = "121",
        Name = "xyz",
        Description = "def"
    };    

    actual.Should().BeEquivalentTo(expected);   // This succeeds, but should fail
}

对 BeEquivalentTo 的调用似乎忽略了对象中定义的属性，只将对象视为集合。

如何让框架检查集合的属性和内容？

编辑 好像是a known issue

有人知道解决方法吗？

Answer 1

比较实现 IEnumerable 并有额外属性要比较的类时，它是 known issue。

这是一种破解比较的方法。

public class Entity : IEnumerable<int>
{
    private int[] ints = new[] { 1 };

    public int Id { get; set; }

    public string Name { get; set; }

    public IEnumerator<int> GetEnumerator() => ((IEnumerable<int>)ints).GetEnumerator();

    IEnumerator IEnumerable.GetEnumerator() => ((IEnumerable<int>)ints).GetEnumerator();
}

[TestMethod]
public void EquivalenceTest()
{
    var expected = new Entity
    {
        Id = 1,
        Name = "abc",
    };

    var actual = new Entity
    {
        Id = 1,
        Name = "abc",
    };

    actual.Should().BeEquivalentTo(expected, opt => opt
        .Using<Entity>(e =>
            e.Subject.Should().Match<Entity>(f => f.Name == e.Expectation.Name)
            .And.Subject.Should().Match<Entity>(f => f.Id == e.Expectation.Id)
                .And.Subject.Should().BeEquivalentTo(e.Expectation)
        )
        .WhenTypeIs<Entity>());
}