Moq Raise event of Func<T1, Task>

I have a third-party class MqttClient which has an event inside it (Func<T1, Task>). I want to listen for this event inside the MyClient class and when it gets invoked, I update the property IsConnected inside my class. For my tests, I have mocked the IMqttClient interface, and I want to raise that event so that I can test that my property gets updated when it happens. However, when I try to do this I get an error about parameter count mismatches. I've found a lot of examples about using EventHandler<T> but since this class is outside of my control, I need it to work with a Func.

> System.Reflection.TargetParameterCountException: 'Parameter count mismatch.'

Here are the tests I've tried:

[Fact]
public void Connect_IsConnectedSetToTrue()
{
    MqttClientConnectedEventArgs eventArgs = new(new MqttClientConnectResult());
    _mockMqttNetClient.Raise(x => x.ConnectedAsync += null);
    _mqttClient.Connect();
    Assert.True(_mqttClient.IsConnected);
}

[Fact]
public void Connect_IsConnectedSetToTrue()
{
     MqttClientConnectedEventArgs eventArgs = new(new MqttClientConnectResult());
    _mockMqttNetClient.Raise(x => x.ConnectedAsync += null, eventArgs);
    _mqttClient.Connect();
    Assert.True(_mqttClient.IsConnected);
}

[Fact]
public void Connect_IsConnectedSetToTrue()
{
    MqttClientConnectedEventArgs eventArgs = new(new MqttClientConnectResult());
    _mockMqttNetClient.Raise(x => x.ConnectedAsync += null, this, eventArgs);
    _mqttClient.Connect();
    Assert.True(_mqttClient.IsConnected);
}

The MyClient class:

public class MyClient
{
    private readonly IMqttClient _client;

    public bool IsConnected { get; private set; } = false;

    public MQTTClient(IMQTTNetClientFactory mqttNetFactory)
    {
        _client = mqttNetFactory.Create();
        _client.ConnectedAsync += Client_ConnectedAsync;
    }

    public async Task Connect()
    {
        MqttClientOptions options = new MqttClientOptionsBuilder()
            .WithTcpServer(_url, _port)
            .WithCredentials(_username, _password)
            .WithProtocolVersion(MqttProtocolVersion.V500)
            .Build();

        await _client.ConnectAsync(options);
    }

   
    private Task Client_ConnectedAsync(MqttClientConnectedEventArgs arg)
    {
        _logger.LogInformation("Client connected to the MQTT broker.");
        IsConnected = true;
        return Task.FromResult(0);
    }
}

This is what the event looks like inside the MqttClient class.

public interface IMqttClient : IDisposable
{
    event Func<MqttClientConnectedEventArgs, Task> ConnectedAsync;
}

Thanks,
Adam

As @Ralf said

> The raise overload you use expects that it is an Eventhandler(the sender+args thingy) when only given an args class and fiddles a sender into the call

Doing it this way solved my issue.

_mockMqttNetClient.Raise(x => x.DisconnectedAsync += null, new object[] { eventArgs });