c# - 我如何使用 xUnit Assert.RaisesAny？

Question

如何使用 xUnit Assert.RaisesAny()？我似乎找不到任何示例。

我收到以下语法错误

The event 'IMqttServer.Started' can only appear on the left hand side of += or -=

这是有道理的，因为我没有订阅它，但我不知道 RaisesAny() 使用什么语法

基本上，我只是想检查 Broker 是否已启动，至少有 1 个客户端连接到它并且它已停止。

附言MqttServer 是一个 Mqtt Broker 实现，它是 MqttNet 的一部分

这是我的测试

public class ResearchTestingOnly
{

    private readonly ITestOutputHelper output;

    public ResearchTestingOnly(ITestOutputHelper output)
    {
        this.output = output;
    }


    [Fact]
    public void Test1()
    {

        IMqttServer _mqttBroker = new MqttFactory().CreateMqttServer();

        var receivedEvents = new List<string>();

        _mqttBroker.ClientConnected += delegate (object sender, MqttClientConnectedEventArgs args)
        {
            receivedEvents.Add(args.ClientId);
        };

        Assert.RaisesAny<EventHandler>(_mqttBroker.Started);

        Assert.RaisesAny<MqttClientConnectedEventArgs>(_mqttBroker.ClientConnected);

        Assert.RaisesAny<EventHandler>(_mqttBroker.Stopped);

        //** Start Broker
        Task _brokerTask = Task.Run(() => _mqttBroker.StartAsync(new MqttServerOptions()));

        //** Wait 10 Seconds
        var pause = new ManualResetEvent(false);
        pause.WaitOne(10000);

        //** Stop Broker
        Task _brokerStopTask = Task.Run(() => _mqttBroker.StopAsync());

        //** Wait for Broker Tasks to Complete
        Task.WaitAll(_brokerTask, _brokerStopTask);

        output.WriteLine($"Number of Clients Connected: {receivedEvents.Count}");
        foreach(var b in receivedEvents)
        {
            output.WriteLine(b);
        }
    }
}

Answer 1

基于 the source for EventAssertsTests (将 x 替换为 _mqttBroker):

[Fact]
public static void GotExpectedEvent()
{
    var evt = Assert.RaisesAnyAsync<EventArgs>(
        h => _mqttBroker.Started += h,
        h => _mqttBroker.Started -= h,
        () => Task.Run(() => _mqttBroker.StartAsync(new MqttServerOptions())));

    Assert.NotNull(evt);
    Assert.Equal(_mqttBroker, evt.Sender);
    Assert.Equal(EventArgs.Empty, evt.Arguments);
}