From 550e2b4373d80b67d1d3286c606c6cf74e51a191 Mon Sep 17 00:00:00 2001
From: Alexander Zinchuk <alx.zinchuk@gmail.com>
Date: Fri, 8 Mar 2024 12:48:42 +0100
Subject: [PATCH] Link: Fix incorrent parsing for invite links (#4342)

---
 src/components/common/UsernameInput.tsx |  6 +++---
 src/util/deepLinkParser.ts              |  5 +----
 src/util/username.ts                    | 10 ++++++----
 3 files changed, 10 insertions(+), 11 deletions(-)

diff --git a/src/components/common/UsernameInput.tsx b/src/components/common/UsernameInput.tsx
index f44492f3a..b500a35de 100644
--- a/src/components/common/UsernameInput.tsx
+++ b/src/components/common/UsernameInput.tsx
@@ -7,7 +7,7 @@ import { getActions } from '../../global';
 import { TME_LINK_PREFIX } from '../../config';
 import { debounce } from '../../util/schedulers';
 import {
-  isUsernameValid, MAX_USERNAME_LENGTH, MIN_USERNAME_LENGTH, USERNAME_REGEX,
+  isUsernameValid, MAX_USERNAME_LENGTH, MIN_UPDATE_USERNAME_LENGTH, USERNAME_REGEX,
 } from '../../util/username';
 
 import useLang from '../../hooks/useLang';
@@ -53,7 +53,7 @@ const UsernameInput: FC<OwnProps> = ({
       return [];
     }
 
-    if (username.length < MIN_USERNAME_LENGTH) {
+    if (username.length < MIN_UPDATE_USERNAME_LENGTH) {
       return [undefined, lang(`${langPrefix}InvalidShort`)];
     }
     if (username.length > MAX_USERNAME_LENGTH) {
@@ -92,7 +92,7 @@ const UsernameInput: FC<OwnProps> = ({
 
     setUsername(newUsername);
 
-    const isValid = newUsername === '' ? true : isUsernameValid(newUsername);
+    const isValid = newUsername === '' ? true : isUsernameValid(newUsername, true);
     if (!isValid) return;
 
     onChange?.(newUsername);
diff --git a/src/util/deepLinkParser.ts b/src/util/deepLinkParser.ts
index a59e4c988..8d8fddcb3 100644
--- a/src/util/deepLinkParser.ts
+++ b/src/util/deepLinkParser.ts
@@ -2,6 +2,7 @@ import type { ThreadId } from '../types';
 
 import { RE_TG_LINK, RE_TME_LINK } from '../config';
 import { ensureProtocol } from './ensureProtocol';
+import { isUsernameValid } from './username';
 
 export type DeepLinkMethod = 'resolve' | 'login' | 'passport' | 'settings' | 'join' | 'addstickers' | 'addemoji' |
 'setlanguage' | 'addtheme' | 'confirmphone' | 'socks' | 'proxy' | 'privatepost' | 'bg' | 'share' | 'msg' | 'msg_url' |
@@ -492,7 +493,3 @@ function getPathParams(url: URL) {
 function getQueryParams(url: URL) {
   return Object.fromEntries(url.searchParams);
 }
-
-function isUsernameValid(username: string) {
-  return /^\D([a-zA-Z0-9_]){1,64}$/.test(username);
-}
diff --git a/src/util/username.ts b/src/util/username.ts
index e4ff590a8..174597319 100644
--- a/src/util/username.ts
+++ b/src/util/username.ts
@@ -1,9 +1,11 @@
-export const MIN_USERNAME_LENGTH = 5;
+export const MIN_USERNAME_LENGTH = 3; // Some bots have 3-letter usernames
+export const MIN_UPDATE_USERNAME_LENGTH = 5; // 4 letter usernames are only available on Fragment
 export const MAX_USERNAME_LENGTH = 32;
-export const USERNAME_REGEX = /^\D([a-zA-Z0-9_]+)$/;
+export const USERNAME_REGEX = /^[a-zA-Z]\w+$/;
 
-export function isUsernameValid(username: string) {
-  return username.length >= MIN_USERNAME_LENGTH
+export function isUsernameValid(username: string, isUpdating?: boolean) {
+  const minUsernameLength = isUpdating ? MIN_UPDATE_USERNAME_LENGTH : MIN_USERNAME_LENGTH;
+  return username.length >= minUsernameLength
     && username.length <= MAX_USERNAME_LENGTH
     && USERNAME_REGEX.test(username);
 }