模拟了一个返回 true 的方法仍然返回 false

问题描述

我有一个这样的控制器方法：

const char*

测试这个控制器的测试用例如下：

public class ValuesController : Controller
{
    private readonly IService fService;
    public ValuesController( IService fService)
    {
        this.fService = fService;            
    }

    public IActionResult InsertDetails( [FromForm]Details details,IFormFile file)
    {
        bool result = fService.SaveDetails(details,file);
        return OK();
    }
}

即使我模拟 public class ValuesControllerTests { readonly Mock<IService> mockService = new Mock<IService>(); [TestMethod] public void SaveDetails_Test_Success() { var details = GetMockDetails(); // gets the sample DTO values mockService.Setup(x => x.SaveDetails(details,GetFile())).Returns(true); ---- this is returning false even after mocking the value var controller = new ValuesController(mockService.Object); controller.ControllerContext.HttpContext = new DefaultHttpContext(); var res = controller.InsertDetails(details,GetFile()) as OkObjectResult; Assert.AreEqual("File Details Saved Successfully",res.Value.ToString()); Assert.AreEqual(200,res.StatusCode); } IFormFile GetFile() { return new FormFile(new MemoryStream(Encoding.UTF8.GetBytes("This is a dummy file")),"Data","dummy.txt"); } } 方法返回 SaveDetails，它也总是返回 true。
谁能告诉我我在这里做错了什么？非常感谢。

解决方法

期望是使用与调用被测成员时使用的不同的 IFormFile（引用/实例）设置的。这会导致模拟返回被调用成员的默认值，该值是 false，因为它是一个布尔值。

当调用 GetFile() 时，它每次都返回一个新实例。

所以要么使用相同的实例，就像使用 details

public void SaveDetails_Test_Success() {
    Details details = GetMockDetails();
    IFormFile file = GetFile(); //single instance
    mockService.Setup(x => x.SaveDetails(details,file)).Returns(true); //used here
    ValuesController controller = new ValuesController(mockService.Object);
    controller.ControllerContext.HttpContext = new DefaultHttpContext();
    var res = controller.InsertDetails(details,file) as OkObjectResult; //and here
    Assert.AreEqual("File Details Saved Successfully",res.Value.ToString());
    Assert.AreEqual(200,res.StatusCode);
 }

或者使用参数匹配器（如 It.IsAny<>()

）放松期望

public void SaveDetails_Test_Success() {
    Details details = GetMockDetails();
    mockService.Setup(x => x.SaveDetails(details,It.IsAny<IFormFile>())).Returns(true); //<-- NOTE
    ValuesController controller = new ValuesController(mockService.Object);
    controller.ControllerContext.HttpContext = new DefaultHttpContext();
    var res = controller.InsertDetails(details,GetFile()) as OkObjectResult; 
    Assert.AreEqual("File Details Saved Successfully",res.StatusCode);
 }

,

您的 Setup 的问题在于它过于具体。
请记住，参数匹配是基于类的引用检查。

mockService
      .Setup(service => service.SaveDetails(It.IsAny<Details>(),It.IsAny<IFormFile>()))
      .Returns(true); 

如果您想验证通话，则需要
保存 GetFile 的结果，然后进行断言：

public void SaveDetails_Test_Success()
{
    //Arrange
    var details = GetMockDetails(); 
    var file = GetFile(); //same instance is used everywhere

    mockService
      .Setup(x => x.SaveDetails(It.IsAny<Details>(),It.IsAny<IFormFile>()))
      .Returns(true); 

    var controller = new ValuesController(mockService.Object);
    controller.ControllerContext.HttpContext = new DefaultHttpContext();
    
    //Act
    var result = controller.InsertDetails(details,file);
    
    //Assert
    var res = Assert.IsAssignableForm<OkObjectResult>(result); //Here we test the assignability as well
    Assert.AreEqual("File Details Saved Successfully",res.Value.ToString());
    //Assert.AreEqual(200,res.StatusCode); //This assert is unnecessary

    mockService
      .Verify(x => x.SaveDetails(details,file),Times.Once); 
}

我建议不要将控制器操作的响应转换为 OkObjectResult，我建议也声明它。 （就像我在上面的测试用例中所做的一样）