patch infinite money glitch by mutexing coin transfers and blackjack (#526)

Author: Alex L

src/commandDetails/coin/transfer.ts

@@ -1,15 +1,16 @@
 import { SapphireClient, container } from '@sapphire/framework';
 import { CommandInteraction, EmbedBuilder, Message, User, userMention } from 'discord.js';
 import {
-  CodeyCommandOptionType,
   CodeyCommandDetails,
+  CodeyCommandOptionType,
+  SapphireAfterReplyType,
   SapphireMessageExecuteType,
-  getUserFromMessage,
   SapphireMessageResponseWithMetadata,
-  SapphireAfterReplyType,
+  getUserFromMessage,
 } from '../../codeyCommand';
 import { getCoinBalanceByUserId, transferTracker } from '../../components/coin';
 import { getCoinEmoji } from '../../components/emojis';
+import { gamesByPlayerId } from '../../components/games/blackjack.js';
 
 const coinTransferExecuteCommand: SapphireMessageExecuteType = async (
   client,
@@ -57,6 +58,20 @@ const coinTransferExecuteCommand: SapphireMessageExecuteType = async (
     return new SapphireMessageResponseWithMetadata(`You can't transfer less than 1 coin.`, {});
   }
 
+  if (transferTracker.transferringUsers.has(sendingUser.id)) {
+    return new SapphireMessageResponseWithMetadata(
+      `Please finish your current transfer first.`,
+      {},
+    );
+  }
+
+  if (gamesByPlayerId.has(sendingUser.id)) {
+    return new SapphireMessageResponseWithMetadata(
+      `Please finish your current blackjack game before transferring coins.`,
+      {},
+    );
+  }
+
   const transfer = await transferTracker.startTransfer(
     sendingUser,
     receivingUser,

src/commandDetails/games/blackjack.ts

@@ -1,37 +1,39 @@
 import { container } from '@sapphire/framework';
 import {
-  Colors,
-  EmbedBuilder,
-  ButtonBuilder,
-  ButtonStyle,
   ActionRowBuilder,
+  ButtonBuilder,
   ButtonInteraction,
+  ButtonStyle,
+  Colors,
   ComponentType,
+  EmbedBuilder,
 } from 'discord.js';
 import {
+  CodeyCommandDetails,
+  CodeyCommandOptionType,
+  SapphireMessageExecuteType,
+  SapphireMessageResponse,
+  getUserFromMessage,
+} from '../../codeyCommand';
+import {
+  UserCoinEvent,
   adjustCoinBalanceByUserId,
   getCoinBalanceByUserId,
-  UserCoinEvent,
+  transferTracker,
 } from '../../components/coin';
 import { getCoinEmoji, getEmojiByName } from '../../components/emojis';
 import {
   BlackjackAction,
   BlackjackHand,
   BlackjackStage,
   CardSuit,
-  endGame,
   GameState,
+  endGame,
+  gamesByPlayerId,
   performGameAction,
   startGame,
 } from '../../components/games/blackjack';
 import { pluralize } from '../../utils/pluralize';
-import {
-  CodeyCommandDetails,
-  CodeyCommandOptionType,
-  SapphireMessageExecuteType,
-  SapphireMessageResponse,
-  getUserFromMessage,
-} from '../../codeyCommand';
 
 // CodeyCoin constants
 const DEFAULT_BET = 10;
@@ -223,6 +225,14 @@ const blackjackExecuteCommand: SapphireMessageExecuteType = async (
     return `You don't have enough coins to place that bet. ${getEmojiByName('codey_sad')}`;
   }
 
+  if (transferTracker.transferringUsers.has(author)) {
+    return `Please finish your current coin transfer before starting a game.`;
+  }
+
+  if (gamesByPlayerId.has(author)) {
+    return `Please finish your current game before starting another one!`;
+  }
+
   // Initialize the game
   let game = startGame(bet, author, channel);
   if (!game) {

src/components/coin.ts

@@ -1,19 +1,19 @@
-import _, { uniqueId } from 'lodash';
-import { openDB } from './db';
 import { SapphireClient } from '@sapphire/framework';
 import {
-  Colors,
   ActionRowBuilder,
+  BaseMessageOptions,
   ButtonBuilder,
+  ButtonStyle,
+  Colors,
   EmbedBuilder,
   User,
-  ButtonStyle,
-  BaseMessageOptions,
 } from 'discord.js';
+import _, { uniqueId } from 'lodash';
 import { SapphireSentMessageType } from '../codeyCommand';
+import { updateMessageEmbed } from '../utils/embeds';
 import { pluralize } from '../utils/pluralize';
+import { openDB } from './db';
 import { getCoinEmoji, getEmojiByName } from './emojis';
-import { updateMessageEmbed } from '../utils/embeds';
 
 export enum BonusType {
   Daily = 0,
@@ -323,9 +323,11 @@ const TransferTimeout = 600000; // in ms (600000 ms == 10 mins)
 
 class TransferTracker {
   transfers: Map<string, Transfer>; // id, transfer
+  transferringUsers: Set<string>;
 
   constructor() {
     this.transfers = new Map<string, Transfer>();
+    this.transferringUsers = new Set<string>();
   }
   getTransferFromId(id: string): Transfer | undefined {
     return this.transfers.get(id);
@@ -351,8 +353,9 @@ class TransferTracker {
       reason: reason,
       result: TransferResult.Pending,
     };
-    const transfer = new Transfer(channelId, client, transferId, transferState);
+    const transfer = new Transfer(channelId, client, transferId, transferState, this);
     this.transfers.set(transferId, transfer);
+    this.transferringUsers.add(sender.id);
     setTimeout(async () => {
       if (transfer.state.result === TransferResult.Pending) {
         transfer.state.result = TransferResult.Timeout;
@@ -370,6 +373,7 @@ class TransferTracker {
       throw new Error(`No transfer with transfer ID ${transferId} found`);
     }
 
+    this.transferringUsers.delete(transfer.state.sender.id);
     if (transfer.state.result === TransferResult.Pending) return;
     await transfer.handleTransaction();
   }
@@ -383,17 +387,20 @@ export class Transfer {
   state: TransferState;
   transferId: string;
   transferMessage!: SapphireSentMessageType;
+  tracker: TransferTracker;
 
   constructor(
     channelId: string,
     client: SapphireClient<boolean>,
     transferId: string,
     transferState: TransferState,
+    tracker: TransferTracker,
   ) {
     this.channelId = channelId;
     this.state = transferState;
     this.client = client;
     this.transferId = transferId;
+    this.tracker = tracker;
   }
 
   // called if state is (believed to be) no longer pending. Transfers coins and updates balances if transfer is confirmed
@@ -420,6 +427,8 @@ export class Transfer {
         <string>(this.state.reason ?? ''),
         this.client.user?.id,
       );
+
+      this.tracker.transferringUsers.delete(this.state.sender.id);
     }
   }
 

src/components/games/blackjack.ts

@@ -38,7 +38,7 @@ export enum CardSuit {
 }
 
 // keeps track of games by player's Discord IDs
-const gamesByPlayerId = new Map<string, BlackjackGame>();
+export const gamesByPlayerId = new Map<string, BlackjackGame>();
 
 // maps action Enum to game action
 const gameActionsMap = new Map<BlackjackAction, () => Action>([