feat: add patch to add generic types to eventemitter2

EventEmitter2 has types, but they're very basic and not very type safe.
I created this patch, because my improved types haven't been merged into the official package.

Signed-off-by: Tilman Vatteroth <git@tilmanvatteroth.de>

backend/src/events.ts

@@ -3,6 +3,7 @@
  *
  * SPDX-License-Identifier: AGPL-3.0-only
  */
+import { EventMap } from 'eventemitter2';
 
 export const eventModuleConfig = {
   wildcard: false,
@@ -18,3 +19,7 @@ export enum NoteEvent {
   PERMISSION_CHANGE = 'note.permission_change' /** noteId: The id of the [@link Note], which permissions are changed. **/,
   DELETION = 'note.deletion' /** noteId: The id of the [@link Note], which is being deleted. **/,
 }
+
+export interface NoteEventMap extends EventMap {
+  [NoteEvent.PERMISSION_CHANGE]: (noteId: number) => void;
+}

backend/src/notes/notes.service.ts

@@ -17,7 +17,7 @@ import {
   MaximumDocumentLengthExceededError,
   NotInDBError,
 } from '../errors/errors';
-import { NoteEvent } from '../events';
+import { NoteEvent, NoteEventMap } from '../events';
 import { Group } from '../groups/group.entity';
 import { GroupsService } from '../groups/groups.service';
 import { HistoryEntry } from '../history/history-entry.entity';
@@ -54,7 +54,7 @@ export class NotesService {
     @Inject(forwardRef(() => AliasService)) private aliasService: AliasService,
     private realtimeNoteService: RealtimeNoteService,
     private realtimeNoteStore: RealtimeNoteStore,
-    private eventEmitter: EventEmitter2,
+    private eventEmitter: EventEmitter2<NoteEventMap>,
   ) {
     this.logger.setContext(NotesService.name);
   }

backend/src/permissions/permissions.service.ts

@@ -14,7 +14,7 @@ import {
 } from '../config/guest_access.enum';
 import noteConfiguration, { NoteConfig } from '../config/note.config';
 import { PermissionsUpdateInconsistentError } from '../errors/errors';
-import { NoteEvent } from '../events';
+import { NoteEvent, NoteEventMap } from '../events';
 import { Group } from '../groups/group.entity';
 import { GroupsService } from '../groups/groups.service';
 import { SpecialGroup } from '../groups/groups.special';
@@ -36,7 +36,7 @@ export class PermissionsService {
     private readonly logger: ConsoleLoggerService,
     @Inject(noteConfiguration.KEY)
     private noteConfig: NoteConfig,
-    private eventEmitter: EventEmitter2,
+    private eventEmitter: EventEmitter2<NoteEventMap>,
   ) {}
 
   /**

backend/src/realtime/realtime-note/realtime-note.ts

@@ -8,7 +8,7 @@ import {
   encodeMetadataUpdatedMessage,
 } from '@hedgedoc/commons';
 import { Logger } from '@nestjs/common';
-import { EventEmitter2 } from 'eventemitter2';
+import { EventEmitter2, EventMap } from 'eventemitter2';
 import { Awareness } from 'y-protocols/awareness';
 
 import { Note } from '../../notes/note.entity';
@@ -16,10 +16,15 @@ import { WebsocketAwareness } from './websocket-awareness';
 import { WebsocketConnection } from './websocket-connection';
 import { WebsocketDoc } from './websocket-doc';
 
+export interface MapType extends EventMap {
+  destroy: () => void;
+  beforeDestroy: () => void;
+}
+
 /**
  * Represents a note currently being edited by a number of clients.
  */
-export class RealtimeNote extends EventEmitter2 {
+export class RealtimeNote extends EventEmitter2<MapType> {
   protected logger: Logger;
   private readonly websocketDoc: WebsocketDoc;
   private readonly websocketAwareness: WebsocketAwareness;

backend/src/realtime/realtime-note/test-utils/mock-realtime-note.ts

@@ -7,13 +7,13 @@ import { EventEmitter2 } from 'eventemitter2';
 import { Mock } from 'ts-mockery';
 
 import { Note } from '../../../notes/note.entity';
-import { RealtimeNote } from '../realtime-note';
+import { MapType, RealtimeNote } from '../realtime-note';
 import { WebsocketAwareness } from '../websocket-awareness';
 import { WebsocketDoc } from '../websocket-doc';
 import { mockAwareness } from './mock-awareness';
 import { mockWebsocketDoc } from './mock-websocket-doc';
 
-class MockRealtimeNote extends EventEmitter2 {
+class MockRealtimeNote extends EventEmitter2<MapType> {
   constructor(
     private note: Note,
     private doc: WebsocketDoc,