feat: optional WHITELIST environment variable

.env.example

@@ -22,4 +22,12 @@ ENABLE_REACTIONS="true"
 QUEUED_REACTION="🔁"
 WORKING_REACTION="⚙️"
 DONE_REACTION="✅"
-ERROR_REACTION="⚠️"
+ERROR_REACTION="⚠️"
+
+# Whitelist (optional)
+# The bot will only answer to these phone numbers (separated by commas)
+# Leave this empty if you want the bot to answer to anyone
+## Examples:
+##  Brazil: 5515999999999 # 55 = country code # 15 = area code # 999999999 = phone number
+##  US: 14155551111 # 1 = country code # 415 = area code # 5551111 = phone number
+WHITELIST="5519999999999,14155551111"

src/clients/whatsapp.ts

@@ -1,8 +1,13 @@
 import qrcode from "qrcode-terminal";
 import cli from "../clients/cli";
-import { Client } from "whatsapp-web.js";
+import { Client, GroupChat } from "whatsapp-web.js";
 import { handleMessage } from "../handlers/message";
 import { handleCommand } from "../handlers/command";
+import { intersection } from "../utils";
+
+// filtering empty strings due to how Array.split() works
+const WHITELIST = process.env.WHITELIST?.split(",").filter(e => e != "") ?? []
+const WHITELIST_ENABLED = WHITELIST.length != 0
 
 export const whatsapp = new Client({
   puppeteer: {
@@ -42,14 +47,37 @@ whatsapp.on("ready", () => {
 });
 
 whatsapp.on("message", async (message) => {
-  const sender = message.from;
-  console.log(`Message received from ${sender}`);
-
-  if (sender == "status@broadcast") {
-    console.log("Its a status broadcast, ignoring...");
+  if (message.from == "status@broadcast") {
     return;
   }
 
+  const chat = await message.getChat()
+  const contact = await message.getContact()
+  const sender = contact.id.user
+
+  const _messageType = chat.isGroup ? "Group" : "DM"
+  const _sender = `${contact.pushname}[${sender}]`
+  console.log(`${_messageType} message received from ${_sender}`);
+
+  if (WHITELIST_ENABLED) {
+    const isWhitelisted = WHITELIST.includes(sender)
+
+    if (chat.isGroup) {
+      const participants = (chat as GroupChat).participants.map(user => user.id.user)
+      const whitelistedParticipants = intersection(WHITELIST, participants)
+
+      if (whitelistedParticipants.length == 0) {
+        console.log("There are no whitelisted participants in this group. Ignoring.")
+        return
+      }
+    } else {
+      if (!isWhitelisted) {
+        console.log(`${_sender} is not whitelisted. Ignoring.`)
+        return
+      }
+    }
+  }
+
   if (message.body.startsWith("!")) {
     const [command, ...args] = message.body.split(" ");
     await handleCommand(message, command, args.join(" "));

src/utils.ts

@@ -3,6 +3,12 @@ import { config } from "./config";
 import dotenv from "dotenv";
 dotenv.config();
 
+export function intersection<T>(array1: T[], array2: T[]) {
+  const set = new Set(array1);
+  return array2.filter(value => set.has(value));
+};
+
+
 const ENABLE_REACTIONS =
   (process.env.ENABLE_REACTIONS as
     | "true"