feat(cooldowns): restrict user to a command every 2 seconds. (#283)

* refactor: Abstract cooldowns
* refactor: make isCooled function return only bool
* style: lint fixes #283

Co-authored-by: Eddie Jaoude <[email protected]>
Co-authored-by: David <[email protected]>

Author: 3 people

src/commands.ts

@@ -2,6 +2,7 @@ import { Message } from 'discord.js';
 
 import commandList, { fallback } from './commandHandlers';
 import config from './config';
+import cooldown from './cooldown';
 
 const { COMMAND_PREFIX, defaultEmbed } = config;
 
@@ -10,6 +11,13 @@ export const commands = async (message: Message) => {
     return;
   }
 
+  if (cooldown.isCooled(message.author.id)) {
+    message.channel.send(
+      `:clock1: Too fast! Only **1** command each **${config.COOLDOWN_SECONDS}** seconds.`
+    );
+    return;
+  }
+
   const args = message.content.slice(COMMAND_PREFIX.length);
   const command = args.split(/ +/).shift()!.toLowerCase();
 
@@ -25,5 +33,6 @@ export const commands = async (message: Message) => {
     message.channel.send(
       await matching.command(args.slice(command.length + 1), embed, message)
     );
+    cooldown.setCool(message.author.id);
   }
 };

src/config.ts

@@ -18,6 +18,7 @@ export default {
     'delete',
   ],
   COMMAND_PREFIX: process.env.COMMAND_PREFIX || '$',
+  COOLDOWN_SECONDS: 2,
   INTRO_CHANNEL: 'introductions',
   GENERAL_CHANNEL: 'general',
   BOT_CHANNEL_ID: process.env.DISCORD_BOT_CHANNEL_ID,

src/cooldown.ts

@@ -0,0 +1,14 @@
+import { Collection, Snowflake } from 'discord.js';
+import config from './config';
+
+const collection = new Collection<Snowflake, number>();
+
+export default {
+  isCooled: (id: Snowflake): boolean => {
+    const nextCommand = collection.get(id);
+    return !!nextCommand && nextCommand > Date.now();
+  },
+  setCool: (id: Snowflake): void => {
+    collection.set(id, Date.now() + config.COOLDOWN_SECONDS * 1000);
+  },
+};