当 Web API 操作方法返回 IHttpActionResult 时，如何对其进行单元测试？

Question

假设这是我的操作方法

public IHttpActionResult Get(int id)
{
    var status = GetSomething(id);
    if (status)
    {
        return Ok();
    }
    else
    {
        return NotFound();
    }
}

测试将是

var httpActionResult = controller.Get(1);

在这之后我如何检查我的http状态码？

Answer 1

这是Kiran Challa的公认答案，为NUnit改编；

var valuesController = controller;
// if your action returns: NotFound()
IHttpActionResult actionResult = valuesController.Get(10);
var notFoundRes = actionResult as NotFoundResult;
Assert.IsNotNull(notFoundRes);

// if your action returns: Ok()
actionResult = valuesController.Get(11);
var posRes = actionResult as OkResult;
Assert.IsNotNull(posRes);

// if your action was returning data in the body like: Ok<string>("data: 12")
actionResult = valuesController.Get(12);
var conNegResult = actionResult as OkNegotiatedContentResult<string>;
Assert.IsNotNull(conNegResult);
Assert.AreEqual("data: 12", conNegResult.Content);

// if your action was returning data in the body like: Content<string>(HttpStatusCode.Accepted, "some updated data");
actionResult = valuesController.Get(13);
var negResult = actionResult as NegotiatedContentResult<string>;
Assert.IsNotNull(negResult);
Assert.AreEqual(HttpStatusCode.Accepted, negResult.StatusCode);
Assert.AreEqual("some updated data", negResult.Content);

Answer 2

是时候重新提出一个死问题了

当前的答案都依赖于将响应对象转换为已知类型。不幸的是，在不了解控制器实现的情况下，响应似乎没有可用的层次结构或隐式转换路径。考虑以下几点：

public class MixedCodeStandardController : ApiController {

    public readonly object _data = new Object();

    public IHttpActionResult Get() {
        return Ok(_data);
    }

    public IHttpActionResult Get(int id) {
        return Content(HttpStatusCode.Success, _data);
    }
}

测试类：

var testController = new MixedCodeStandardController();

var getResult = testController.Get();
var posRes = getResult as OkNegotiatedContentResult<object>;
Assert.IsType<OkNegotiatedContentResult<object>>(getResult);
Assert.AreEqual(HttpStatusCode.Success, posRes.StatusCode);
Assert.AreEqual(testController._data, posRes.Content);

var idResult = testController.Get(1);
var oddRes = getResult as OkNegotiatedContentResult<object>; // oddRes is null
Assert.IsType<OkNegotiatedContentResult<object>>(idResult); // throws failed assertion
Assert.AreEqual(HttpStatusCode.Success, oddRes.StatusCode); // throws for null ref
Assert.AreEqual(testController._data, oddRes.Content); // throws for null ref

从黑匣子外部来看，响应流本质上是相同的。测试必须知道控制器如何实现返回调用以以这种方式对其进行测试。

相反，使用返回的IHttpActionResult中的HttpActionMessage对象。这可确保测试可以保持一致，即使控制器代码可能不是：

var testController = new MixedCodeStandardController();

var getResult = testController.Get();
var getResponse = getResult.ExecuteAsync(CancellationToken.None).Result;
Assert.IsTrue(getResponse.IsSuccessStatusCode);
Assert.AreEqual(HttpStatusCode.Success, getResponse.StatusCode);

var idResult = testController.Get(1);
var idResponse = idResult.ExecuteAsync(CancellationToken.None).Result;
Assert.IsTrue(idResponse.IsSuccessStatusCode);
Assert.AreEqual(HttpStatusCode.Success, idResponse.StatusCode);

Answer 3

这里Ok（）只是OkResult类型的一个助手，它将响应状态设置为HttpStatusCode.Ok...所以您可以检查您的操作结果的实例是否是OkResult...一些示例（用XUnit编写）：

// if your action returns: NotFound()
IHttpActionResult actionResult = valuesController.Get(10);
Assert.IsType<NotFoundResult>(actionResult);

// if your action returns: Ok()
actionResult = valuesController.Get(11);
Assert.IsType<OkResult>(actionResult);

// if your action was returning data in the body like: Ok<string>("data: 12")
actionResult = valuesController.Get(12);
OkNegotiatedContentResult<string> conNegResult = Assert.IsType<OkNegotiatedContentResult<string>>(actionResult);
Assert.Equal("data: 12", conNegResult.Content);

// if your action was returning data in the body like: Content<string>(HttpStatusCode.Accepted, "some updated data");
actionResult = valuesController.Get(13);
NegotiatedContentResult<string> negResult = Assert.IsType<NegotiatedContentResult<string>>(actionResult);
Assert.Equal(HttpStatusCode.Accepted, negResult.StatusCode);
Assert.Equal("some updated data", negResult.Content);