Custom editors: onDidEdit should not have optional data

[bpasero]

Refs: #93767

It seems to me that onDidEdit should force to send the edit, but this typing allows undefined from the fire method:

[mjbvz]

I believe the custom editor api typings are correct since they only use Event

This looks like a strict null error in our EventEmitter types. We should only let you omit the argument for EventEmitter<void>

[jrieken]

Yeah, that's an event emitter problem. Unsure when/why that happened...

[bpasero]

@mjbvz isn't 1ed9dcd a breaking API change?

[mjbvz]

Strictly perhaps, but not practically

This change will cause compile errors for extensions compiled with strict mode TS that were mistakenly calling fire(undefined). However doing that was almost certainly a bug in their code. Old extension code will keep working just fine but now the error will be obvious if an extension author recompiles it

[bpasero]

That maybe deserves a shoutout in release notes.