✨ Allow using username as receiver

signalbot/bot.py

@@ -275,6 +275,9 @@ def _resolve_receiver(self, receiver: str) -> str:
         if self._is_valid_uuid(receiver):
             return receiver
 
+        if self._is_username(receiver):
+            return receiver
+
         if self._is_group_id(receiver):
             return receiver
 
@@ -306,6 +309,31 @@ def _is_valid_uuid(self, receiver_uuid: str):
         except ValueError:
             return False
 
+    def _is_username(self, receiver_username: str) -> bool:
+        """
+        Check if username has correct format, as described in https://support.signal.org/hc/en-us/articles/6712070553754-Phone-Number-Privacy-and-Usernames#username_req
+        Additionally, cannot have more than 9 digits and the digits cannot be 00.
+        """
+        split_username = receiver_username.split(".")
+        if len(split_username) == 2:
+            characters = split_username[0]
+            digits = split_username[1]
+            if len(characters) < 3 or len(characters) > 32:
+                return False
+            if not re.match(r"^[A-Za-z\d_]+$", characters):
+                return False
+            if len(digits) < 2 or len(digits) > 9:
+                return False
+            try:
+                digits = int(digits)
+                if digits == 0:
+                    return False
+                return True
+            except ValueError:
+                return False
+        else:
+            return False
+
     def _is_group_id(self, group_id: str) -> bool:
         """Check if group_id has the right format, e.g.
 

tests/test_bot.py

@@ -113,6 +113,39 @@ def test_listen_valid_invalid_phone_number(self):
         self.assertSetEqual(self.signal_bot.user_chats, expected_user_chats)
 
 
+class TestUsernameValidation(BotTestCase):
+    def test_valid_username(self):
+        valid_usernames = [
+            "Usr.99",
+            "UserName.99",
+            "username.999999999",
+            "UserName99.99",
+            "_Use_rName99_.99",
+            "username.999999999",
+            "usernameeeeeeeeeeeeeeeeeeeeeeeee.999999999",
+        ]
+        for valid_username in valid_usernames:
+            self.assertTrue(self.signal_bot._is_username(valid_username))
+
+    def test_invalid_username(self):
+        invalid_usernames = [
+            "Us.99",
+            "Usr.9",
+            ".UserName99",
+            ".UserName.99",
+            "UserName99",
+            "UserName99.",
+            "username.9999999999",
+            "user@name.999",
+            "UserName99.0",
+            "UserName99.00",
+            "UserName99.000000000",
+            ".usernameeeeeeeeeeeeeeeeeeeeeeeeee.99",
+        ]
+        for invalid_username in invalid_usernames:
+            self.assertFalse(self.signal_bot._is_username(invalid_username))
+
+
 class TestRegisterCommand(BotTestCase):
     def test_register_one_command(self):
         self.signal_bot.register(DummyCommand())