为什么使用It.is<或It.IsAny<如果我只能定义一个变量? [英] Why use It.is<> or It.IsAny<> if I could just define a variable?
问题描述
当我看到这段代码时,我已经使用moq一段时间了.
Hi I've been using moq for a while when I see this code.
我必须在我的一个回购单中设置退货.
I have to setup a return in one of my repo.
mockIRole.Setup(r => r.GetSomething(It.IsAny<Guid>(), It.IsAny<Guid>(),
It.IsAny<Guid>())).Returns(ReturnSomething);
我有三个参数,我只是在网上的一篇文章或博客中看到了这些参数.
I have three parameters and I just saw these in one of articles or blog on the net.
It.Is<>
或It.IsAny<>
对一个对象有什么用途?如果我可以使用Guid.NewGuid()
或其他类型,那为什么要使用It.Is
?
What is the use of It.Is<>
or It.IsAny<>
for an object? if I could use Guid.NewGuid()
or other types then why use It.Is
?
很抱歉,我不确定我的问题是对的还是我在测试中缺少一些知识. 但这两种方式似乎都没有错.
I'm sorry I'm not sure if my question is right or am I missing some knowledge in testing. But it seems like there is nothing wrong either way.
推荐答案
使用It.IsAny<>
,It.Is<>
或变量均具有不同的用途.它们提供了越来越具体的方法来设置或验证方法时匹配参数.
Using It.IsAny<>
, It.Is<>
, or a variable all serve different purposes. They provide increasingly specific ways to match a parameter when setting up or verifying a method.
使用It.IsAny<>
设置的方法将匹配您给该方法提供的 any 参数.因此,在您的示例中,以下调用将全部返回相同的内容(ReturnSomething
):
The method set up with It.IsAny<>
will match any parameter you give to the method. So, in your example, the following invocations would all return the same thing (ReturnSomething
):
role.GetSomething(Guid.NewGuid(), Guid.NewGuid(), Guid.NewGuid());
Guid sameGuid = Guid.NewGuid();
role.GetSomething(sameGuid, sameGuid, sameGuid);
role.GetSomething(Guid.Empty, Guid.NewGuid(), sameGuid);
所传递的Guid
的实际值无关紧要.
It doesn't matter the actual value of the Guid
that was passed.
It.Is<>
构造对于方法的设置或验证很有用,可让您指定与参数匹配的函数.例如:
The It.Is<>
construct is useful for setup or verification of a method, letting you specify a function that will match the argument. For instance:
Guid expectedGuid = ...
mockIRole.Setup(r => r.GetSomething(
It.Is<Guid>(g => g.ToString().StartsWith("4")),
It.Is<Guid>(g => g != Guid.Empty),
It.Is<Guid>(g => g == expectedGuid)))
.Returns(ReturnSomething);
这使您不仅可以限制任何值,还可以宽容接受的东西.
This allows you to restrict the value more than just any value, but permits you to be lenient in what you accept.
设置(或验证)带有变量的方法参数时,是说您要精确该值.用另一个值调用的方法将永远不会与您的设置/验证相匹配.
When you set up (or verify) a method parameter with a variable, you're saying you want exactly that value. A method called with another value will never match your setup/verify.
Guid expectedGuids = new [] { Guid.NewGuid(), Guid.NewGuid(), Guid.NewGuid() };
mockIRole.Setup(r => r.GetSomething(expectedGuids[0], expectedGuids[1], expectedGuids[2]))
.Returns(ReturnSomething);
现在只有一种情况,其中GetSomething
将返回ReturnSomething
:当所有Guid
都与您为其设置的期望值匹配时.
Now there's exactly one case where GetSomething
will return ReturnSomething
: when all Guid
s match the expected values that you set it up with.
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