如何模拟私有的只读 IList<T>使用最小起订量的属性 [英] How to mock a private readonly IList<T> property using moq

问题描述

我正在尝试模拟此列表:

I'm trying to mock this list:

private readonly IList<MyClass> myList = new List<MyClass>();

使用这个(如此处所示):

IList<MyClass> mockList = Builder<MyClass>.CreateListOfSize(5).Build();
mockObj.SetupGet<IEnumerable<MyClass>>(o => o.myList).Returns(stakeHoldersList);

但是在运行时我得到一个 InvalidCastException:

However at runtime I get an InvalidCastException:

Unable to cast object of type 'System.Collections.Generic.List`1[MyClass]' to
type 'System.Collections.ObjectModel.ReadOnlyCollection`1[MyClass]'.

我做错了什么?

推荐答案

好吧，我认为模拟私有实现细节很奇怪，而且坦率地说是错误的.您的测试不应依赖于私有实现细节.

但如果我是你，我会这样做的方法是添加一个构造函数:

But the way that I'd do this if I were you is to add a constructor:

public Foo {
    private readonly IList<MyClass> myList;
    public Foo(IList<MyClass> myList) { this.myList = myList; }
}

然后使用 Moq 模拟 IList 的实例并通过构造函数传递它.

and then use Moq to mock an instance of IList<MyClass> and pass that through the constructor.

如果你不喜欢这个建议，或者，创建一个虚拟财产:

If you don't like that suggestion, alternatively, make a virtual property:

public Foo {
    private readonly IList<MyClass> myList = new MyList();
    public virtual IList<MyClass> MyList { get { return this.myList; } }
}

然后使用 Moq 覆盖该属性.

and then use Moq to override that property.

你还是做错了.

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