带字符串的Moq中的Setup函数

有趣的问题是,使用表达式几乎可以做到这一点。因为setup方法接受一个表达式,所以可以在运行时构建它。

编译时只需要根据模拟方法的返回类型将表达式强制转换为适当的lambda类型。不幸的是,Moq没有提供 Setup 超载裸体 Expression

public abstract class Fruit
{
}

public class Apple :Fruit
{
}

public interface IFactory {
    Fruit CreateFruit(string type);
    void VoidMethod(int intParameter);
}

[TestClass]
public class UnitTest1 {
    [TestMethod]
    public void TestMethod1() {
        var factoryMock = new Mock<IFactory>(); 

        Expression factoryCall = Expression.Lambda(
            Expression.Call(Expression.Variable(typeof(IFactory), "f"), "CreateFruit", new Type[]{}, Expression.Constant("Apple")), 
            Expression.Parameter(typeof(IFactory), "f"));

        //factoryMock.Setup(f=>f.CreateFruit("Apple")).Returns(new Apple());

        factoryMock.Setup((Expression<Func<IFactory, Fruit>>)factoryCall).Returns(new Apple());
        var ret = factoryMock.Object.CreateFruit("Apple");
        Assert.IsInstanceOfType(ret, typeof(Apple));
    }
}