c# - 值不能为空。参数名称 : request

Question

我正在使用 nunit 创建单元测试，所有这些代码在运行时都运行良好。

我在下面有这个 protected HttpResponseMessage 代码，当它返回时我的 Controller 正在调用它。

但是，报错:

"Value cannot be null. Parameter name: request" is displaying.

当我检查请求时，它实际上是 null。

问题: 我将如何编写单元测试代码以返回 HttpResponseMessage？

错误显示在这一行:

  protected HttpResponseMessage Created<T>(T result) => Request.CreateResponse(HttpStatusCode.Created, Envelope.Ok(result));

这是我的 Controller :

    [Route("employees")]
    [HttpPost]
    public HttpResponseMessage CreateEmployee([FromBody] CreateEmployeeModel model)
    {
        //**Some code here**//

        return Created(new EmployeeModel
        {
            EmployeeId = employee.Id,
            CustomerId = employee.CustomerId,
            UserId = employee.UserId,
            FirstName = employee.User.FirstName,
            LastName = employee.User.LastName,
            Email = employee.User.Email,

            MobileNumber = employee.MobileNumber,
            IsPrimaryContact = employee.IsPrimaryContact,
            OnlineRoleId = RoleManager.GetOnlineRole(employee.CustomerId, employee.UserId).Id,
            HasMultipleCompanies = EmployeeManager.HasMultipleCompanies(employee.UserId)
        });
    }

Answer 1

你得到的原因:

An exception of type 'System.ArgumentNullException' occurred in System.Web.Http.dll but was not handled in user code Additional information: Value cannot be null.

是因为Request对象是null。

解决方案是在测试中创建一个 Controller 实例，例如:

    var myApiController = new MyApiController
    {
        Request = new System.Net.Http.HttpRequestMessage(),
        Configuration = new HttpConfiguration()
    };

这样，在创建 MyApiController 类的新实例时，我们正在初始化 Request 对象。此外，还需要提供关联的配置对象。

最后，您的 Api Controller 的单元测试示例可能是:

[TestClass]
public class MyApiControllerTests
{
    [TestMethod]
    public void CreateEmployee_Returns_HttpStatusCode_Created()
    {
        // Arrange
        var controller = new MyApiController
        {
            Request = new System.Net.Http.HttpRequestMessage(),
            Configuration = new HttpConfiguration()
        };

        var employee = new CreateEmployeeModel
        {
            Id = 1
        };

        // Act
        var response = controller.CreateEmployee(employee);

        // Assert
        Assert.AreEqual(response.StatusCode, HttpStatusCode.Created);
    }
}