C# 异步任务 - 单元测试

Question

我是 C# 单元测试的新手，必须测试该方法是否正常工作。

这是我到目前为止所拥有的：

  public async Task<IHttpActionResult> Post(API_FIRM_LINK aPI_FIRM_LINK)
    {
        db.API_FIRM_LINK.Add(aPI_FIRM_LINK);
        await db.SaveChangesAsync();

        return Created(aPI_FIRM_LINK);
    }

测试方法：不确定我是否走在正确的道路上 如果有人可以根据我的测试提供示例

     public async Task PostTest()

    {
        ////Arrange
        API_FIRM_LINKController controller = new API_FIRM_LINKController();

        API_FIRM_LINK aPI_FIRM_LINK = null;

        IHttpActionResult expectedResult = await controller.Post(aPI_FIRM_LINK);
        //act

        IHttpActionResult result = await controller.Post(API_FIRM_LINK, aPI_FIRM_LINK);


        ////Assert
        IComparer<IHttpActionResult> comparer = new IHttpActionResultComparer();
       // Assert.IsTrue(comparer.Equals(expectedResult, result));

        Assert.IsNotNull(result);
        Console.Write(result);

Answer 1

如果您使用现代版本，则Microsoft.VisualStudio.TestTools.UnitTesting可以使用异步测试方法，就像您在问题中所做的那样。

如果要测试 Post 函数是否返回预期数据，请执行以下操作：

[TestMethod()]
public async Task PostTestAsync()
{
    var controller = new API_FIRM_LINKController();
    // TODO: do some preparations, so you can expect a specific return value
    IHttpActionResult expectedResult = ...

    // call PostAsync and await for it to finish
    Task taskPost =  controller.PostAsync(API_FIRM_LINK, aPI_FIRM_LINK);
    IHttpActionResult result = await taskPost;

    // of course this can be done in one line:
    IHttpActionResult result = await controller.PostAsync(API_FIRM_LINK, aPI_FIRM_LINK);

    // compare whether result equals expectedResult
    // for example: create a class that implements IComparer<IHttpActionResult>
    IComparer<IHttpActionResult> comparer = new IHttpActionResultComparer();
    Assert.IsTrue(comparer.Equals(expectedResult, result);
}

如果您使用无法使用异步测试的测试套件：

[TestMethod()]
public void PostTest()
{
    var controller = new API_FIRM_LINKController();
    IHttpActionResult expectedResult = ...

    // call PostAsync and wait for it to finish
    Task taskPost =  Task.Run(() => controller.PostAsync(API_FIRM_LINK, aPI_FIRM_LINK));
    taskPost.Wait();
    IHttpActionResult result = taskPost.Result;

    // TODO: compare result with expected result
}

Answer 2

从来没有async void，基本上。

[TestMethod]
public async Task PostTest() {...}

如果您的测试框架不支持Task测试：更改测试框架。