使用Moq验证集合中类的方法调用

Question

我不确定我是否以正确的方式使用Moq，所以如果有人可以提供帮助，我将不胜感激。

我想测试集合中对象的Clone（）方法调用。 测试如下所示：

[Test]
public void CloneTest()
{
    var mdFake = new Mock<MachineDecision>();
    var clonable = mdFake.As<ICloneable>();
    clonable.Setup(x => x.Clone()).Verifiable();

    var decision = new Decision()
    {
        MachineDecisions = new List<MachineDecision> { mdFake.Object }
    };

    var newDecision = (Decision) decision.Clone();

    clonable.Verify(x => x.Clone()); 
}

测试失败： Moq.MockException : Expected invocation on the mock at least once, but was never performed: x => x.Clone()但我认为它实际上应该通过。

使用的类如下所示：

public class Decision : Entity<Guid>, ICloneable
{
    public Decision()
    {
        Id = Guid.NewGuid();
        MachineDecisions = new List<MachineDecision>();
    }

    public List<MachineDecision> MachineDecisions { get; set; }

    public object Clone()
    {
        var obj = new Decision();
        if (this.MachineDecisions != null)
        {
            obj.MachineDecisions = MachineDecisions.Select(item => (MachineDecision) item.Clone()).ToList();
        }
        return obj;
    }
}

public class MachineDecision : Entity<Guid>, ICloneable
{
    //...
}

Answer 1

有两个选项。

首先 ，您可以虚拟实现方法Clone()的实现，并且测试将为“绿色”

public class MachineDecision : Entity<Guid>, ICloneable
{
    public virtual object Clone()
    {
        throw new NotImplementedException();
    }
}

其次 ，您可以从ICloneable接口调用Clone()方法： (MachineDecision)(item as ICloneable).Clone() ; 并且您的测试也将为“绿色”。

    public class Decision : Entity<Guid>, ICloneable
    {
        public Decision()
        {
            Id = Guid.NewGuid();
            MachineDecisions = new List<MachineDecision>();
        }

        public List<MachineDecision> MachineDecisions { get; set; }

        public object Clone()
        {
            var obj = new Decision();
            if (this.MachineDecisions != null)
            {
                obj.MachineDecisions = MachineDecisions.Select(item =>
                {
                    return (MachineDecision)(item as ICloneable).Clone();
                }).ToList();
            }
            return obj;
        }
    }

我意识到现在这不是最好的代码，但是由您自己决定如何进一步重构它。

Answer 2

我会这样：

[Test]
public void CloneTest()
{
    // create the mock
    var mdFake = new Mock<MachineDecision>();

    var decision = new Decision
    {
        // setup (pass it to my collection)
        MachineDecisions = new List<MachineDecision> { mdFake.Object }
    };

    // call the method being tested (you need to make Clone() virtual)
    decision.Clone();

    // check for the side effects -> It was called once !
    mdFake.Verify(x => x.Clone(), Times.Once());
}

我希望这可以帮助你。

编辑 -很抱歉，正如评论中所指出的-我忘了提及，我的建议是要求您将Clone() （在MachineDecision ）- virtual ，这在您的情况下可能并不理想。

Answer 3

尝试这个：

...
clonable.Expect(x => x.Clone()).Verifiable().Returns(null);
...
clonable.Verify();