在单元测试中模拟类中的类 [英] Mock a Class in a Class in a Unit Test

问题描述

我在单元测试中有以下代码

I have the following code in a unit test

using Moq;
using OtherClass;
[TestClass]
public class TestClass
{
    [TestMethod]
    public void TestMethod()
    {
        OtherClass other = new OtherClass();
        OtherClass.foo();
    }
}

这里是另一个类

using ThirdClass;
public class OtherClass
{
    public void foo()
    {
        ThirdClass third = new ThirdClass();
        third.bar();
    }
}

ThirdClass 仍在开发中，但我希望能够使用 moq 运行我的单元测试.有没有办法告诉 moq 在 TestClass 内模拟 ThirdClass 而没有 OtherClass 使用/依赖 moq?理想情况下是这样的:

ThirdClass is still under development, but I want to be able to run my unit tests using moq. Is there a way to tell moq to mock ThirdClass inside TestClass without having OtherClass use/depend on moq? Ideally something like:

public void TestMethod()
{
    OtherClass other = new OtherClass();
    Mock<ThirdClass> third =  new Mock<ThirdClass>();
    third.setup(o => o.bar()).Returns(/*mock implementation*/);
    /*use third in all instances of ThirdClass in OtherClass*/
    OtherClass.foo();
}

推荐答案

OtherClass 类中的方法 foo() 不可单元测试，因为您创建了真实服务的新实例你不能嘲笑它.

Method foo() in class OtherClass is not unit testable because you creating new instance of real service and you cannot mock it.

如果你想模拟它，那么你必须使用依赖注入注入 ThirdClass.

If you want to mock it then you have to inject ThirdClass with dependency injection.

OtherClass 的例子是:

public class OtherClass
{
    private readonly ThirdClass _thirdClass;
    public OtherClass(ThirdClass thirdClass) 
    {
         _thirdClass = thirdClass;
    }
    public void foo()
    {
        _thirdClass.bar();
    }
}

您的测试方法与测试其他类的示例可以是:

Your test method with example of testing other class can be:

public void TestMethod()
{
    // Arrange
    Mock<ThirdClass> third =  new Mock<ThirdClass>();
    third.setup(o => o.bar()).Returns(/*mock implementation*/);

    OtherClass testObject= new OtherClass(third);

    // Action
    testObject.foo();

    // Assert
    ///TODO: Add some assertion.
}

您可以使用 Unity DI 容器.

You can use example try with Unity DI container.

这篇关于在单元测试中模拟类中的类的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！