如何在单元测试中模拟一个函数

Question

我如何通过 NMock3 对 GetData 进行单元测试？

如果可以模拟 prcessA.Run 和 ProcessA 中的 "result" 就好了。

IAnotherService 不能作为 GetData 的参数，因为它取决于 GetData 中的处理值。

有什么想法吗？

服务 1

public class Service1 : IService1
{
    public Service1()
    {
    }

    public string GetData(int a)
    {
        // some process depends on input
        int b = a * new Random().Next();

        IAnotherService anotherService = new AnotherService(b);
        ProcessA processA = new ProcessA(anotherService);
        processA.Run();
        return processA.result;
    }
}

简化流程A

public class ProcessA
{
    public string result;
    private IAnotherService anotherService;

    public ProcessA(IAnotherService anotherService)
    {
        this.anotherService = anotherService;
    }

    public void Run()
    {
        // Some other process here
        this.result = this.anotherService.Run();
    }
}

测试方法 1

[TestMethod]
public void TestMethod1()
{
    using (mockFactory.Ordered())
    {
        // Nothing to Mock
    }

    IService1 service1 = new Service1();
    string aaa = service1.GetData(1);

    Assert.AreEqual("XXX", aaa);
}

Answer 1

如前所述，您需要模拟相关服务并设置您期望的 return。

我在下面做了一个测试，它有效。我用的是Moq，但是原理是一样的

 public interface IAnotherService
 {
     string Run();
 }

public class ProcessA
{
    public string result;
    private readonly IAnotherService _anotherService;

    public ProcessA(IAnotherService anotherService)
    {
        this._anotherService = anotherService;
    }

    public string Run()
    {
        // Some other process here
        return _anotherService.Run();
    }   
}

然后运行测试

[Test]
public void TestMethod1()
{
   //Create a Mock
   var mockService = new Mock<IAnotherService>();
   //Set the expected result
   mockService.Setup(method => method.Run()).Returns("XXX");

   //Inject the mock
   var process = new ProcessA(mockService.Object);
   var result = process.Run();

   //Assert the result     
   Assert.AreEqual("XXX", result);
}

编辑

正如所讨论的，我已经编辑了我的答案，希望能满足您的需要。

 public interface IService1
    {
        string GetData(int a);
        int ValueForB { get; set; }
    }

public class Service1Consumer : IService1
{
    private readonly IAnotherService _anotherServiceImplementation;

    public Service1Consumer(IAnotherService service)
    {
        _anotherServiceImplementation = service;
    }

    public string GetData(int a)
    {
        ValueForB = a * new Random().Next();
        _anotherServiceImplementation.ValueFor = b;
        var processA = new ProcessA(_anotherServiceImplementation);
        return processA.Run();
    }
}

public interface IAnotherService
{
    int ValueForB { get; set; }
}

public class AnotherService : IAnotherService
{
}

public class ProcessA
{
    public string result;
    private readonly IAnotherService _anotherService;

    public ProcessA(IAnotherService anotherService)
    {
        _anotherService = anotherService;
    }

    public string Run()
    {
        return "XXXX";
    }
}

然后是测试。

  [Test]
  public void TestMethod1()
  {
      //Create a Mock
      var mockAnotherService = new Mock<IAnotherService>();
      //Set the property value when called.
      mockAnotherService.Setup(method => method.ValueForB).Returns(10);//Test 1

      var service1Consumer = new Service1Consumer(mockAnotherService.Object);
      var result = service1Consumer.GetData();

      Assert.AreEqual("XXXX",result);

   }

希望这能为您指明正确的方向。谢谢

如何在单元测试中模拟一个函数

How to mock a function in an unit test

c#

unit-testing

nmock