tg fix: (release v0.3.0) phone number formats

* on tg desktop phones are prepended with a "+"
* on tg phone, no "+"

src/bot.js

@@ -77,8 +77,11 @@ bot.on("msg:contact", async (ctx) => {
   log.debug(ctx.update, "msg:contact received");
   const contact = ctx.msg.contact;
 
-  if (ctx.from.id === contact.user_id) {
-    await cache.set(contact.user_id, contact.phone_number.slice(1));
+  if (
+    ctx.from.id === contact.user_id &&
+    util.isKenyanNumber(contact.phone_number)
+  ) {
+    await cache.set(contact.user_id, contact.phone_number);
 
     return ctx.reply(
       "Phone number successfully linked. /start the bot again to access your Sarafu account."

src/util.js

@@ -15,7 +15,20 @@ function parseUssdResponse(input) {
   };
 }
 
+function isKenyanNumber(input) {
+  if (input.substr(0, 1) === "+") {
+    input = input.split("+")[1];
+  }
+
+  if (input.substr(0, 3) === "254") {
+    return true;
+  }
+
+  return false;
+}
+
 module.exports = {
   createKeyboard,
   parseUssdResponse,
+  isKenyanNumber,
 };