我正在使用异步 xUnit 测试,我注意到不一致的传递行为:
public async Task FetchData()
{
//Arrange
var result = await arrangedService.FetchDataAsync().ConfigureAwait(false);
//Assert
}
我已经查看了此测试执行的调用堆栈,并已验证我的所有库代码都在每个任务后调用 .ConfigureAwait(false)
。然而,尽管如此,这个测试和其他测试在执行 Run All
时会间歇性地失败,但是当我在调试器上遍历时通过断言和手动检查。很明显我没有做正确的事情。我尝试在测试本身中删除对 ConfigureAwait(false)
的调用,以防有特殊的 xUnit 同步上下文,但它没有改变任何东西。以一致的方式测试异步代码的最佳方法是什么?
编辑 好的,这是我尝试创建一个正在运行的代码的 super 简化示例,以提供正在发生的事情的示例:
using Graph = Microsoft.Azure.ActiveDirectory.GraphClient;
public async Task FetchData()
{
var adUsers = baseUsers //IEnumerable<Graph.User>
.Cast<Graph.IUser>()
.ToList();
var nextPageUsers = Enumerable
.Range(GoodIdMin, GoodIdMax)
.Select(number => new Graph.User
{
Mail = (-number).ToString()
})
.Cast<Graph.IUser>()
.ToList();
var mockUserPages = new Mock<IPagedCollection<Graph.IUser>>();
mockUserPages
.Setup(pages => pages.MorePagesAvailable)
.Returns(true);
mockUserPages
.Setup(pages => pages.CurrentPage)
.Returns(new ReadOnlyCollection<Graph.IUser>(adUsers));
mockUserPages
.Setup(pages => pages.GetNextPageAsync())
.ReturnsAsync(mockUserPages.Object)
.Callback(() =>
{
mockUserPages
.Setup(pages => pages.CurrentPage)
.Returns(new ReadOnlyCollection<Graph.IUser>(nextPageUsers));
mockUserPages
.Setup(pages => pages.MorePagesAvailable)
.Returns(false);
});
var mockUsers = new Mock<Graph.IUserCollection>();
mockUsers
.Setup(src => src.ExecuteAsync())
.ReturnsAsync(mockUserPages.Object);
var mockGraphClient = new Mock<Graph.IActiveDirectoryClient>();
mockGraphClient
.Setup(src => src.Users)
.Returns(mockUsers.Object);
var mockDbUsers = CreateBasicMockDbSet(baseUsers.Take(10)
.Select(user => new User
{
Mail = user.Mail
})
.AsQueryable());
var mockContext = new Mock<MyDbContext>();
mockContext
.Setup(context => context.Set<User>())
.Returns(mockDbUsers.Object);
var mockGraphProvider = new Mock<IGraphProvider>();
mockGraphProvider
.Setup(src => src.GetClient()) //Creates an IActiveDirectoryClient
.Returns(mockGraphClient.Object);
var getter = new UserGetter(mockContext.Object, mockGraphProvider.Object);
var result = await getter.GetData().ConfigureAwait(false);
Assert.True(result.Success); //Not the actual assert
}
下面是在 var result = ...
行上执行的代码:
public UserGetterResult GetData()
{
var adUsers = await GetAdUsers().ConfigureAwait(false);
var dbUsers = Context.Set<User>().ToList(); //This is the injected context from before
return new UserGetterResult //Just a POCO
{
AdUsers = adUsers
.Except(/*Expression that indicates whether
or not this user is in the database*/)
.ProjectTo<User>()
.ToList(),
DbUsers = dbUsers.ProjectTo<User>().ToList() //Automapper 6.1.1
};
}
private async Task<List<User>> GetAdUsers()
{
var userPages = await client //Injected IActiveDirectoryClient from before
.Users
.ExecuteAsync()
.ConfigureAwait(false);
var users = userPages.CurrentPage.ToList();
while(userPages.MorePagesAvailable)
{
userPages = await userPages.GetNextPageAsync().ConfigureAwait(false);
users.AddRange(userPages.CurrentPage);
}
return users;
}
该代码的目的是获取AD中但不在数据库中的用户列表以及在数据库中的用户列表。
EDIT EDIT 因为我忘记在原始更新中包含它,所以错误都发生在调用 `IUserCollection.ExecuteAsync() 时。
最佳答案
IUserCollection.ExecuteAsync()
似乎根据原始帖子中显示的内容正确配置。
现在关注下面的方法...
private async Task<List<User>> GetAdUsers() {
var userPages = await client //Injected IActiveDirectoryClient from before
.Users
.ExecuteAsync()
.ConfigureAwait(false);
var users = userPages.CurrentPage.ToList();
while(userPages.MorePagesAvailable) {
userPages = await userPages.GetNextPageAsync().ConfigureAwait(false);
users.AddRange(userPages.CurrentPage);
}
return users;
}
我很关心用户页面在模拟中是如何设置的。考虑到 GetAdUsers
方法的流程,最好使用 SetupSequence
模拟重复调用 CurrentPage
和 MorePagesAvailable
.
var mockUserPages = new Mock<IPagedCollection<Graph.IUser>>();
mockUserPages
.SetupSequence(_ => _.MorePagesAvailable)
.Returns(true) // First time called to enter while loop
.Returns(false); // Second time called to exit while loop
mockUserPages
.SetupSequence(_ => _.CurrentPage)
.Returns(new ReadOnlyCollection<Graph.IUser>(adUsers)) // First time called to get List
.Returns(new ReadOnlyCollection<Graph.IUser>(nextPageUsers)); // Second time called to get next page
mockUserPages
.Setup(pages => pages.GetNextPageAsync())
.ReturnsAsync(mockUserPages.Object); // No need for callback
关于c# - 如何正确编写异步 XUnit 测试?,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/48505006/