如何使用Task里面的单元测试void方法

Question

我有一个图形方法CancelChanges()使用和ViewModel调用.我想测试这个方法,但我们内部有一个Task.我们使用Task来不冻结UI.我的测试方法需要等待此任务的结果来检查结果.

代码是:

public override void CancelChanges()
{
        Task.Run(
            async () =>
                {
                    this.SelectedWorkflow = null;
                    AsyncResult<IncidentTypeModel> asyncResult = await this.Dataprovider.GetIncidentTypeByIdAsync(this.Incident.Id);

                    Utils.GetDispatcher().Invoke(
                        () =>
                            {
                                if (asyncResult.IsError)
                                {
                                    WorkflowMessageBox.ShowException(
                                        MessageHelper.ManageException(asyncResult.Exception));
                                }
                                else
                                {
                                    this.Incident = asyncResult.Result;
                                    this.Refreshdesigner();
                                    this.HaveChanges = false;
                                }
                            });
                });
}

而我的测试方法:

/// <summary>
///     A test for CancelChanges
/// </summary>
[TestMethod]
[TestCategory("ConfigTool")]
public void CancelChangesTest()
{
    string storexaml = this._target.Incident.WorkflowXamlString;
    this._target.Incident.WorkflowXamlString = "dsdfsdgfdsgdfgfd";

    this._target.CancelChanges();

    Assert.IsTrue(storexaml == this._target.Incident.WorkflowXamlString);
    Assert.IsFalse(this._target.HaveChanges);
}

我们如何让我的测试等待任务的结果？

谢谢.

Answer 1

使CancelChanges方法返回a Task,然后等待或在测试方法中设置延续.有些人喜欢这样

public override Task CancelChanges()
{
    return Task.Factory.StartNew(() =>
        {
            // Do stuff...
        });
}

注意从变化Task.Run到Task.Factory.StartNew.在这种情况下,这是启动任务的更好方法.然后在测试方法中

[TestMethod]
[TestCategory("ConfigTool")]
public void CancelChangesTest()
{
    string storexaml = this._target.Incident.WorkflowXamlString;
    this._target.Incident.WorkflowXamlString = "dsdfsdgfdsgdfgfd";
    this._target.CancelChanges().ContinueWith(ant => 
        {
            Assert.IsTrue(storexaml == this._target.Incident.WorkflowXamlString);
            Assert.IsFalse(this._target.HaveChanges);
        });
}

您还可以将测试方法标记为async并await在测试方法中使用以执行相同的操作.

我希望这有帮助.