Web API帖子在Fiddler中返回错误请求但在单元测试中返回Ok

Question

我正在尝试编写一个Web API，我们的客户可以将提交数据发布给我们以供将来验证。我有这个（非常简化的）类，这是用户发给我们的：

public class ClientSubmission
{
    [Required]
    [StringLength(maximumLength: 40)]
    public string ApiKey { get; set; }

    [StringLength(maximumLength: 250)]
    public string Name { get; set; }
}

这是我的API控制器：

public class RebateController : ApiController
{
    [HttpPost] // This is probably unnecessary but it's in the code so I put it here
    public IHttpActionResult New(ClientSubmission content)
    {
        if (ModelState.IsValid)
        {
            return Ok(content);
        }

        return BadRequest(ModelState);
    }
}

在Fiddler中，当我传递一个带有ApiKey的JSON对象时，我得到了该对象，当我没有时，我得到了ModelState错误 - 正是我所期待的！但是，在我的两个单元测试中，我得到了OkNegotiatedContentResult<ClientSubmission>两个测试。我做错了什么？

[TestClass]
public class RebateControllerTest
{
    private readonly RebateController _controller;

    public RebateControllerTest()
    {
        _controller = new RebateController();
    }

    [TestMethod]
    public void ValidApiReturnsOk()
    {
        var payload = GetDefault();

        var actionResult = _controller.New(payload);

        Assert.IsInstanceOfType(actionResult, typeof (OkNegotiatedContentResult<ClientSubmission>));
    }

    [TestMethod]
    public void NullApiReturnsBadRequest()
    {
        var payload = GetDefault();

        payload.ApiKey = null;

        var actionResult = _controller.New(payload);

        Assert.IsInstanceOfType(actionResult, typeof (BadRequestResult));
    }

    private static ClientSubmission GetDefault()
    {
        return new ClientSubmission
        {
            ApiKey = "test api key",
            Name = "first name"
        };
    }
}

测试失败：