Event manager is registering something in listener that shouldn't be registered

[mohammed Alteneiji]

The problem

Since if i want multi platform support i tend to create API not to be depend on proxy that used which I create
ITestEvent.java and ITestListener.java which then i implement in it proxy api which can be seen in steps to reproduce.

what i should expect that event to be handled single time but instead it fired 2 times, well this was weird so i checked if i didn't double register the listener or something, and it wasn't so i kept debugging until i reached idea it could be velocity problem,
so after debugging with velocity, so IN VelocityEventManager at registerInternally after collectMethods i inserted this debug code

  public void registerInternally(final PluginContainer pluginContainer, final Object listener) {
    final Class<?> targetClass = listener.getClass();
    final Map<String, MethodHandlerInfo> collected = new HashMap<>();
    collectMethods(targetClass, collected);
    collected.forEach((clazz, coll) -> {
      logger.info("ID? {} | method {}", clazz, coll.method);
    });
    final List<HandlerRegistration> registrations = new ArrayList<>();

after adding debug messages i could see 2 methods registered

[18:26:39] [Velocity Async Event Executor - #0/INFO] [com.velocitypowered.proxy.event.VelocityEventManager]: ID? doSomething(net.limework.test.TestEvent): method public void net.limework.test.TestListener.doSomething(net.limework.test.TestEvent)
[18:26:39] [Velocity Async Event Executor - #0/INFO] [com.velocitypowered.proxy.event.VelocityEventManager]: ID? doSomething(net.limework.test.ITestEvent): method public void net.limework.test.TestListener.doSomething(net.limework.test.ITestEvent)

doSomething(net.limework.test.ITestEvent) shouldn't be registered since it does not have @Subscribe

steps to reproduce

1. create classes in this type of configuration

• ITestEvent.java

package net.limework.test;

public interface ITestEvent {

    int x();
    
}

• TestEvent.java

package net.limework.test;

public record TestEvent(int x) implements ITestEvent {

}

• ITestListener.java

package net.limework.test;

public interface ITestListener<E extends ITestEvent> {

    void doSomething(E event);
    
}

• TestListener.java

package net.limework.test;

import com.velocitypowered.api.event.Subscribe;

public class TestListener implements ITestListener<TestEvent> {
    @Override
    @Subscribe
    public void doSomething(TestEvent event) {
        System.out.println("test event fired " + event.x());
    }
}

2. register TestListener.java

3. fire the event TestEvent.java with example Code used to trigger the event

AtomicInteger i = new AtomicInteger(0);
        server.getEventManager().register(this, new TestListener());
        server.getScheduler().buildTask(this, () -> {
            server.getEventManager().fireAndForget(new TestEvent(i.getAndIncrement()));
        }).repeat(Duration.ofSeconds(1)).schedule();

4. see the console output

[22:19:03 INFO]: test event fired 0
[22:19:03 INFO]: test event fired 0
[22:19:03 INFO]: Listening on /[0:0:0:0:0:0:0:0%0]:25577
[22:19:03 INFO]: Done (0.62s)!
[22:19:04 INFO]: test event fired 1
[22:19:04 INFO]: test event fired 1
[22:19:05 INFO]: test event fired 2
[22:19:05 INFO]: test event fired 2
[22:19:06 INFO]: test event fired 3
[22:19:06 INFO]: test event fired 3
[22:19:07 INFO]: test event fired 4
[22:19:07 INFO]: test event fired 4
[22:19:08 INFO]: test event fired 5
[22:19:08 INFO]: test event fired 5