在 nsubstitute 已接收方法的参数匹配器中匹配 func 委托

Question

我正在尝试检查一个方法是否在类的模拟实例上被调用了特定次数。问题是该方法具有func delegate并且不匹配。

我有以下情况：

public interface ISomeService: IService
{
Task CleanupMethod(CancellationToken cancellationToken);
}
public interface I
{
Task invokedMethod(string aName, Func<IService, Task> action);
}

public class ClassGoingToBeUnitTested
{
// instance of I
private I instanceOfI;
// a list of names.
private static readonly string[] serviceNames =
{
"Name1",
"Name2"
};
// constructor
public ClassGoingToBeUnitTested(I passedInstance)
{
this.instanceOfI = passedInstance;
}

public void methodToBeUnitTested(object cancellationToken)
{
// my logic here
// here I am calling invokedMethod method to known number of times.
// something like this.
try
{
IEnumerable<Task> someTasks = serviceNames.Select(
name => this.instanceOfI.invokedMethod(
name,
service => ((ISomeService)service).CleanupMethod((CancellationToken)cancellationToken)
));
// here I run the tasks
Task.WaitAll(someTasks.ToArray());
}
catch
{
// proper catching of exceptions
}
// other logic
}
}

[TestClass]
public class ClassGoingToBeUnitTestedTest
{
// mock of I interface
private I IMock;
// ClassGoingToBeUnitTested object
ClassGoingToBeUnitTested classGoingToBeUnitTested;
[TestInitialize]
public void init()
{
this.IMock = Substitute.For<I>();
this.classGoingToBeUnitTested = new ClassGoingToBeUnitTested(this.IMock);
}

[TestMethod]
public void methodToBeUnitTested_Success()
{
// Arrange
var cancellationTokenSource = new CancellationTokenSource();
// Act
this.classGoingToBeUnitTested.methodToBeUnitTested(cancellationTokenSource.Token);
// Assert
// this is throwing exception.
this.IMock.Received(1).invokedMethod(
"Name1",
service => ((ISomeService)service).CleanupMethod((CancellationToken)cancellationTokenSource.Token)); // problem lies in this line.
}
}

在上面的代码中，如果我将((ISomeService)service).CleanupMethod((CancellationToken)cancellationTokenSource.Token))更改为Arg.Any<Func<IService, Task>()，它可以完美运行。但我不想为我的用例检查它。

到目前为止，我已经能够调试参数匹配器是否通过引用匹配委托，因此无法正确匹配参数。但我无法正确匹配参数。

我也试图调用委托，但没有成功。我想我错过了一些东西。任何帮助将不胜感激。

Answer 1

我通过使用Invoke解决了这个问题。我首先嘲笑了invokedMethod在调用模拟serviceInstanceMock时调用它的行为，然后检查CleanupMethod在serviceInstanceMock本身上被调用的次数。

[TestClass]
public class ClassGoingToBeUnitTestedTest
{
// mock of I interface
private I IMock;
// mock of ISomeService
private ISomeService someServiceMockInstance;
// ClassGoingToBeUnitTested object
ClassGoingToBeUnitTested classGoingToBeUnitTested;
[TestInitialize]
public void init()
{
this.IMock = Substitute.For<I>();
this.ISomeService = Substitute.For<ISomeService>();
this.classGoingToBeUnitTested = new ClassGoingToBeUnitTested(this.IMock);
}

[TestMethod]
public void methodToBeUnitTested_Success()
{
// Arrange
var cancellationTokenSource = new CancellationTokenSource();
this.IMock.invokedMethod(
Arg.Any<string>,
Arg.Do<Func<IService, Task>(x => x.Invoke(this.someServiceMockInstance)));
// Act
this.classGoingToBeUnitTested.methodToBeUnitTested(cancellationTokenSource.Token);
// Assert
this.IMock.Received(1).invokedMethod(
"Name1",
Arg.Any<Func<IService, Task>()); // changed this
this.IMock.Received(1).invokedMethod(
"Name2",
Arg.Any<Func<IService, Task>()); // added this as well
// adding to check the Received call on the service instance
this.someServiceMockInstance.Received(2).CleanupMethod(cancellationTokenSource.Token);
}
}