单元测试---Mock

mock测试就是在测试过程中，对于某些不容易构造或者不容易获取的对象，用一个虚拟的对象来创建以便测试的测试方法.

using Moq;

// Assumptions:

public interface IFoo
{
    Bar Bar { get; set; }
    string Name { get; set; }
    int Value { get; set; }
    bool DoSomething(string value);
    bool DoSomething(int number, string value);
    string DoSomethingStringy(string value);
    bool TryParse(string value, out string outputValue);
    bool Submit(ref Bar bar);
    int GetCount();
    bool Add(int value);
}

public class Bar 
{
    public virtual Baz Baz { get; set; }
    public virtual bool Submit() { return false; }
}

public class Baz
{
    public virtual string Name { get; set; }
}

上面给了一个类，接下来演示怎么mock这个类，并且模拟某些方法的返回值

var mock = new Mock<IFoo>();
mock.Setup(foo => foo.DoSomething("ping")).Returns(true);

mock.Setup(foo => foo.DoSomething(It.IsAny<int>(),It.IsAny<string>())).Returns(true);

第一行Mock出了一个虚拟对象

第二行说明当调用IFoo的DoSomething(string value)方法，且传入参数"ping"的时候，不论DoSomething里面的代码是什么，都会返回true，即直接跳过DoSomething里面的所有代码

第三行说明当调用IFoo的DoSomething(int num,string value)时，不论传入的num和value值为什么，都返回true

能设置方法的返回值，当然也能设置属性的值

mock.Setup(foo => foo.Name).Returns("bar");

还有一些神奇的操作，我太懒了不想写，放个代码示例方便查看~~

Callbacks

var mock = new Mock<IFoo>();
var calls = 0;
var callArgs = new List<string>();

mock.Setup(foo => foo.DoSomething("ping"))
    .Returns(true)
    .Callback(() => calls++);

Verification

mock.Verify(foo => foo.DoSomething("ping"));

miscellaneous

var mock = new Mock<IFoo>();
mock.SetupSequence(f => f.GetCount())
    .Returns(3)  // will be returned on 1st invocation
    .Returns(2)  // will be returned on 2nd invocation
    .Returns(1)  // will be returned on 3rd invocation
    .Returns(0)  // will be returned on 4th invocation
    .Throws(new InvalidOperationException());