From b5a3ce49591a2a7fd7b2d460d8db60c271140b52 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Micha=C5=82=20Garapich?= <michal@garapich.pl>
Date: Sun, 5 Jun 2022 21:17:13 +0200
Subject: [PATCH] refactor(*): make WebsocketEventEmitter a super class (#1707)

---
 src/games/gateways/games.gateway.ts     | 22 +++++-----------------
 src/players/gateways/players.gateway.ts | 22 ++++------------------
 src/shared/websocket-event-emitter.ts   | 15 +++++++++++++--
 3 files changed, 22 insertions(+), 37 deletions(-)

diff --git a/src/games/gateways/games.gateway.ts b/src/games/gateways/games.gateway.ts
index 6ed561473..7da0c9e6e 100644
--- a/src/games/gateways/games.gateway.ts
+++ b/src/games/gateways/games.gateway.ts
@@ -1,8 +1,4 @@
-import {
-  WebSocketGateway,
-  OnGatewayInit,
-  SubscribeMessage,
-} from '@nestjs/websockets';
+import { WebSocketGateway, SubscribeMessage } from '@nestjs/websockets';
 import { Socket } from 'socket.io';
 import { WsAuthorized } from '@/auth/decorators/ws-authorized.decorator';
 import { PlayerSubstitutionService } from '../services/player-substitution.service';
@@ -14,7 +10,6 @@ import {
 } from '@nestjs/common';
 import { Events } from '@/events/events';
 import { WebsocketEvent } from '@/websocket-event';
-import { serialize } from '@/shared/serialize';
 import { SerializerInterceptor } from '@/shared/interceptors/serializer.interceptor';
 import { Serializable } from '@/shared/serializable';
 import { GameDto } from '../dto/game.dto';
@@ -22,18 +17,15 @@ import { WebsocketEventEmitter } from '@/shared/websocket-event-emitter';
 
 @WebSocketGateway()
 export class GamesGateway
-  implements OnGatewayInit, OnModuleInit, WebsocketEventEmitter<GameDto>
+  extends WebsocketEventEmitter<GameDto>
+  implements OnModuleInit
 {
-  private socket: Socket;
-
   constructor(
     @Inject(forwardRef(() => PlayerSubstitutionService))
     private playerSubstitutionService: PlayerSubstitutionService,
     private events: Events,
-  ) {}
-
-  async emit(event: WebsocketEvent, payload: Serializable<GameDto>) {
-    this.socket.emit(event, await serialize(payload));
+  ) {
+    super();
   }
 
   @WsAuthorized()
@@ -50,10 +42,6 @@ export class GamesGateway
     );
   }
 
-  afterInit(socket: Socket) {
-    this.socket = socket;
-  }
-
   onModuleInit() {
     this.events.gameCreated.subscribe(({ game }) =>
       this.emit(WebsocketEvent.gameCreated, game),
diff --git a/src/players/gateways/players.gateway.ts b/src/players/gateways/players.gateway.ts
index f22a891f8..c285573ef 100644
--- a/src/players/gateways/players.gateway.ts
+++ b/src/players/gateways/players.gateway.ts
@@ -2,7 +2,6 @@ import {
   WebSocketGateway,
   OnGatewayConnection,
   OnGatewayDisconnect,
-  OnGatewayInit,
 } from '@nestjs/websockets';
 import { Socket } from 'socket.io';
 import { Subject } from 'rxjs';
@@ -10,23 +9,16 @@ import { OnModuleInit } from '@nestjs/common';
 import { Events } from '@/events/events';
 import { WebsocketEvent } from '@/websocket-event';
 import { PlayersService } from '../services/players.service';
-import { serialize } from '@/shared/serialize';
 import { WebsocketEventEmitter } from '@/shared/websocket-event-emitter';
 import { PlayerDto } from '../dto/player.dto';
-import { Serializable } from '@/shared/serializable';
 
 @WebSocketGateway()
 export class PlayersGateway
-  implements
-    OnGatewayConnection,
-    OnGatewayDisconnect,
-    OnGatewayInit,
-    OnModuleInit,
-    WebsocketEventEmitter<PlayerDto>
+  extends WebsocketEventEmitter<PlayerDto>
+  implements OnGatewayConnection, OnGatewayDisconnect, OnModuleInit
 {
   private _playerConnected = new Subject<Socket>();
   private _playerDisconnected = new Subject<Socket>();
-  private socket: Socket;
 
   get playerConnected() {
     return this._playerConnected.asObservable();
@@ -36,10 +28,8 @@ export class PlayersGateway
     return this._playerDisconnected.asObservable();
   }
 
-  constructor(private events: Events, private playersService: PlayersService) {}
-
-  async emit(event: WebsocketEvent, payload: Serializable<PlayerDto>) {
-    this.socket.emit(event, await serialize(payload));
+  constructor(private events: Events, private playersService: PlayersService) {
+    super();
   }
 
   handleConnection(socket: Socket) {
@@ -50,10 +40,6 @@ export class PlayersGateway
     this._playerDisconnected.next(socket);
   }
 
-  afterInit(socket: Socket) {
-    this.socket = socket;
-  }
-
   onModuleInit() {
     this.events.playerConnects.subscribe(async ({ playerId }) =>
       this.emit(
diff --git a/src/shared/websocket-event-emitter.ts b/src/shared/websocket-event-emitter.ts
index 4f7e397d8..2bfde32f0 100644
--- a/src/shared/websocket-event-emitter.ts
+++ b/src/shared/websocket-event-emitter.ts
@@ -1,6 +1,17 @@
 import { WebsocketEvent } from '@/websocket-event';
+import { OnGatewayInit } from '@nestjs/websockets';
+import { Socket } from 'socket.io';
 import { Serializable } from './serializable';
+import { serialize } from './serialize';
 
-export interface WebsocketEventEmitter<T> {
-  emit(event: WebsocketEvent, payload: Serializable<T>): void;
+export class WebsocketEventEmitter<T> implements OnGatewayInit<Socket> {
+  protected server: Socket;
+
+  afterInit(socket: Socket) {
+    this.server = socket;
+  }
+
+  protected async emit(event: WebsocketEvent, payload: Serializable<T>) {
+    this.server.emit(event, await serialize(payload));
+  }
 }