gameStore: Added functions to add and retrieve games

Implemented the createGame function which creates a new game, generates
it's id and adds it the the games map.

Also added the retrieveGame function which retrieves a game, given it's
id.

Also added the uuid package to generate unique ids for games.

Fixes #5

Signed-off-by: Sagnik Mandal <[email protected]>

backend/gameStore.js

@@ -1,17 +1,25 @@
 // This module is responsible for setting and retrieving the game state.
+import { v4 as uuid } from 'uuid';
+
 import { GameEngine } from './uno-game-engine/engine';
-const games = map();
+const games = new Map();
 
+/**
+ * Create a new game and store it in the games map
+ * @returns {string} gameId
+*/
 export function createGame() {
-    //todo: generate a unique game id and store
+    const gameId = uuid();
+    const game = new GameEngine();
+    games.set(gameId, game);
+    return gameId;
 }
 
 /**
- *  Retrieves a game from the store using its id.
- *
- * @param {string} id Game id
+ * Retrieve a game from the games map
+ * @param {string} id gameId
  * @returns {GameEngine|null} GameEngine instance
  */
 export function retrieveGame(id) {
-    //todo: Retrieve the game from the store
-}
+    return games.get(id) || null;
+}

backend/package.json

@@ -21,7 +21,8 @@
         "express": "^4.19.2",
         "mongoose": "^8.4.0",
         "ts-node": "^10.9.2",
-        "typescript": "^5.4.5"
+        "typescript": "^5.4.5",
+        "uuid": "^9.0.1"
     },
     "devDependencies": {
         "@types/cors": "^2.8.17",