breaking: Removed [SyncEvent] because ClientRpc/TargetRpc does the same thing, and it's an enormous effort to support the Weaver code.

[miwarnec]

Nobody uses SyncEvent.
Nobody knows how it really works (does it broadcast to everyone, to observers, or only to owner?)

It's a redundant feature. ClientRpc/TargetRpc can be used instead, and it's more obvious who it's sent to.

It also removes a large chunk of weaver magic.
832 LOC for a useless feature.

Let's get rid of the baggage so we can move on into the future :)

[sonarcloud]

Kudos, SonarCloud Quality Gate passed!

0 Bugs
0 Vulnerabilities (and 0 Security Hotspots to review)
0 Code Smells

100.0% Coverage
0.0% Duplication

[James-Frowen]

I agree with removing them, SyncEvents are a confusing feature because they allow you to register handlers on server but it never invokes them on the server.

We should try to add/update docs on alternatives to SyncEvents before we merge this

[James-Frowen]

I will update the docs with some of the info below later, but for now I am just dumping it here.

Extra context on removing SyncEvents

• Critical bug like only being allowed 1 sync var per NetworkBehaviour existed in UNET and mirror for several years without being removed. This implies that not many people use sync events.
• Adding handlers on the server like a normal c# event, but they will never be invoked on the server. This seems is error prune it would be hard to debug why your event is not invoking a handler.
• There are not many examples or tests around SyncEvents there is no clear idea how they should work.

Instead of working out how SyncEvent should ideally work it is simple to remove them as the same behaviour can be achieved with ClientRpc and will lead to more predicable behaviour

Alternative to SyncEvent

public event OnHarm onHarm;
[ClientRpc]
private void RpcOnHarm(float damage, GameObject attacker)
{
    this.onHarm?.Invoke(damage, attacker);
}

[Server]
private void Harm(float damage, GameObject attacker)
{
    // harm stuff here

    // invoke on server
    this.onHarm?.Invoke(damage, attacker); 
    // invoke on client
    RpcOnHarm(damage, attacker);
}

This will let people add handlers to event on server or client, then decide which ones need to be invoked at different times.

For example, the server might want to listen to an even to keep track score, and the client might want to listen to even to show a visual effect.