如何处理 NSubstitute 中的委托参数

Question

我有一个 class 方法，其签名如下：

public async Task<ResponseType> getSuff(string id, 
                                        string moreInfo, 
                                        deletegateName doStuff
                                       ) { // details. }

我正在尝试像这样使用 NSubstitute 模拟此调用：

MyClass helper = Substitute.ForPartsOf<MyClass>();
ResponseType response = new ResponseType();
helper.getSuff(Arg.Any<string>(), 
               Arg.Any<string>(),
               Arg.Any<DelegateDefn>()).Returns(Task.FromResult(response));

但是我遇到运行时错误：

NSubstitute.Exceptions.CouldNotSetReturnDueToNoLastCallException: Could not find a call to return from.

Make sure you called Returns() after calling your substitute (for example: mySub.SomeMethod().Returns(value)), and that you are not configuring other substitutes within Returns() (for example, avoid this: mySub.SomeMethod().Returns(ConfigOtherSub())).

If you substituted for a class rather than an interface, check that the call to your substitute was on a virtual/abstract member. Return values cannot be configured for non-virtual/non-abstract members.

Correct use: mySub.SomeMethod().Returns(returnValue);

Potentially problematic use: mySub.SomeMethod().Returns(ConfigOtherSub()); Instead try: var returnValue = ConfigOtherSub(); mySub.SomeMethod().Returns(returnValue);

我认为问题出在代表身上。我只是想模拟方法，我不希望实际传递的委托被执行。

那么，有谁知道我怎样才能做到这一点？谢谢

Answer 1

NSub 与委托和异步代码完美配合。这是一个简单的例子：

public delegate void SomeDelegate();
public class Foo
{
    public virtual async Task<int> MethodWithDelegate(string something, SomeDelegate d)
    {
        return await Task.FromResult(1);
    }
}

[Test]
public void DelegateInArgument()
{
    var sub = Substitute.For<Foo>();
    sub.MethodWithDelegate("1", Arg.Any<SomeDelegate>()).Returns(1);
    Assert.AreEqual(1, sub.MethodWithDelegate("1", () => {}).Result);
    Assert.AreNotEqual(1, sub.MethodWithDelegate("2", () => {}).Result);
}

请确保您指定的方法是虚拟的或抽象的。从你得到的异常：

If you substituted for a class rather than an interface, check that the call to your substitute was on a virtual/abstract member. Return values cannot be configured for non-virtual/non-abstract members.

如何处理 NSubstitute 中的委托参数

How to handle delegate parameter in NSubstitute

c#

nsubstitute