c# - Assert.ThrowsExceptionAsync 不工作

Question

问题:

我还没有找到很多关于 MSTest V2 的信息例如或documentation . Assert.ThrowsExceptionAsync 的正确使用方法是什么？

public void GetPlaylistByIdAsync_NonExistingPlaylist_ThrowsPlaylistNotFoundException()
{
    var playlistId = Guid.NewGuid().ToString();
    var manager = PlaylistTargetsFakeFactory.GetPlaylistTargetFusionManager();
    Assert.ThrowsException<PlaylistNotFoundException>(async () =>
    {
       await manager.GetPlaylistByIdAsync(playlistId);
    });
}

这也没有通过测试:

Assert.ThrowsException<PlaylistNotFoundException>(() =>
{
    return manager.GetPlaylistByIdAsync(playlistId);
});

Message: Assert.ThrowsException failed. No exception thrown.PlaylistNotFoundException exception was expected.

这对我来说是失败的，即使我已经调试它并且肯定会抛出异常。

由于这仍然是一个 RC，因此可能存在错误。我在尝试转换的 2 个测试中进行了此操作，因此我可以使用 VS 2017。

更新:这通过了。

[TestMethod]
public async Task GetPlaylistByIdAsync_NonExistingPlaylist_ThrowsPlaylistNotFoundException()
{
    var playlistId = Guid.NewGuid().ToString();
    var manager = PlaylistTargetsFakeFactory.GetPlaylistTargetFusionManager();
    //Assert.ThrowsException<PlaylistNotFoundException>(() =>
    //{

    try
    {
        await manager.GetPlaylistByIdAsync(playlistId);
        Assert.Fail();
    }
    catch (PlaylistNotFoundException)
    {
        Assert.IsTrue(true);
    }

    //});
}

更新 2: 在 Stephen Cleary 的回答之后，我做了这个改变。感谢您指出我的误用。我已经更改了一段时间，因为我收到“消息:测试方法 .Test.Models.Helpers.PlaylistTargetFusionManagerTests.GetPlaylistByIdAsync_NonExistingPlaylist_ThrowsPlaylistNotFoundException 抛出异常:System.MissingMethodException:找不到方法:'System.Threading.Tasks.Task 1<!!0> Microsoft.VisualStudio.TestTools.UnitTesting.Assert.ThrowsExceptionAsync(System.Func 1 )'."当我运行测试时。

[TestMethod]
[TestCategory(TestCategories.CSharp)]
[TestCategory(TestCategories.PlaylistTargets)]
public async Task GetPlaylistByIdAsync_NonExistingPlaylist_ThrowsPlaylistNotFoundException()
{
    var playlistId = Guid.NewGuid().ToString();
    var manager = PlaylistTargetsFakeFactory.GetPlaylistTargetFusionManager();
    await Assert.ThrowsExceptionAsync<PlaylistNotFoundException>(() => manager.GetPlaylistByIdAsync(playlistId));
}

我的 packages.json 中有 2 个包

 <package id="MSTest.TestAdapter" version="1.1.9-rc2" targetFramework="net451" />
 <package id="MSTest.TestFramework" version="1.0.8-rc2" targetFramework="net451" />

Answer 1

What is the correct way to use Assert.ThrowsExceptionAsync?

你没有调用 ThrowsExceptionAsync .您正在调用 ThrowsException .调用 ThrowsExceptionAsync 的正确方法是等待它的结果。

这应该有效:

public async Task GetPlaylistByIdAsync_NonExistingPlaylist_ThrowsPlaylistNotFoundException()
{
  var playlistId = Guid.NewGuid().ToString();
  var manager = PlaylistTargetsFakeFactory.GetPlaylistTargetFusionManager();
  await Assert.ThrowsExceptionAsync<PlaylistNotFoundException>(async () =>
  {
     await manager.GetPlaylistByIdAsync(playlistId);
  });
}

或者，更简单地说:

  await Assert.ThrowsExceptionAsync<PlaylistNotFoundException>(() =>
     manager.GetPlaylistByIdAsync(playlistId));