Return a Mock from a Mocked method

问题

I'm not sure how I would do this.

Given I have

public interface IFactory<T> where T : new()
{
    IWrapper<T> GetT(string s);
}

public interface IWrapper<out T> where T : new()
{
    void Execute(Action<T> action);
}

When I do this

public class MoqTest
{
    public void test()
    {
        Mock<IWrapper<basicClass>> wrapperMock = new Mock<IWrapper<basicClass>>();
        Mock<IFactory<basicClass>> factoryMock = new Mock<IFactory<basicClass>>()
            .Setup(p => p.GetT(It.IsAny<string>()))
            .Returns(wrapperMock.Object);
    }
}

I get this

Cannot implicitly convert type Moq.Language.Flow.IReturnsResult<TestNamespace.IFactory<TestNamespace.basicClass>> to Moq.Mock<TestNamespace.IFactory<TestNamespace.basicClass>>. An explicit conversion exists (are you missing a cast?)

Note that these are just mocked example objects.

It seems it doesn't consider the return type equivalent. One being a IReturnResult, the other a Moq.Mock

回答1:

Your problem basically is that you are assigning the result of invoking the Returns method to the factoryMock variable.

You want to first create the mock and assign it to the factoryMock variable and then set the mock up like this:

Mock<IWrapper<basicClass>> wrapperMock = new Mock<IWrapper<basicClass>>();
Mock<IFactory<basicClass>> factoryMock = new Mock<IFactory<basicClass>>();

factoryMock
    .Setup(p => p.GetT(It.IsAny<string>()))
    .Returns(wrapperMock.Object);

来源：https://stackoverflow.com/questions/38244204/return-a-mock-from-a-mocked-method