Allow for Pattern Matching Empty Inline Queries (#4817)

Co-authored-by: Bibo-Joshi <22366557+Bibo-Joshi@users.noreply.github.com>
Co-authored-by: locobott <25104044+locobott@users.noreply.github.com>

.gitignore

@@ -93,6 +93,8 @@ telegram.jpg
 
 # virtual env
 venv*
+pyvenv.cfg
+Scripts/
 
 # environment manager:
 .mise.toml

AUTHORS.rst

@@ -80,6 +80,7 @@ The following wonderful people contributed directly or indirectly to this projec
 - `Kirill Vasin <https://github.com/vasinkd>`_
 - `Kjwon15 <https://github.com/kjwon15>`_
 - `Li-aung Yip <https://github.com/LiaungYip>`_
+- `locobott <https://github.com/locobott>`_
 - `Loo Zheng Yuan <https://github.com/loozhengyuan>`_
 - `LRezende <https://github.com/lrezende>`_
 - `Luca Bellanti <https://github.com/Trifase>`_

changes/unreleased/4817.ZHx38jvj9zKRNZfQh9Xrpb.toml

@@ -0,0 +1,5 @@
+bugfixes = "Allow for pattern matching empty inline queries"
+[[pull_requests]]
+uid = "4817"
+author_uid = "locobott"
+closes_threads = []

src/telegram/ext/_handlers/inlinequeryhandler.py

@@ -118,11 +118,7 @@ class InlineQueryHandler(BaseHandler[Update, CCT, RT]):
                 update.inline_query.chat_type not in self.chat_types
             ):
                 return False
-            if (
-                self.pattern
-                and update.inline_query.query
-                and (match := re.match(self.pattern, update.inline_query.query))
-            ):
+            if self.pattern and (match := re.match(self.pattern, update.inline_query.query)):
                 return match
             if not self.pattern:
                 return True

tests/ext/test_inlinequeryhandler.py

@@ -152,6 +152,28 @@ class TestInlineQueryHandler:
             update.inline_query.query = "not_a_match"
             assert not handler.check_update(update)
 
+    @pytest.mark.parametrize(
+        ("query", "expected_result"),
+        [
+            pytest.param("", True, id="empty string"),
+            pytest.param("not empty", False, id="non_empty_string"),
+        ],
+    )
+    async def test_empty_inline_query_pattern(self, app, query, expected_result):
+        handler = InlineQueryHandler(self.callback, pattern=r"^$")
+        app.add_handler(handler)
+
+        update = Update(
+            update_id=0,
+            inline_query=InlineQuery(
+                id="id", from_user=User(1, "test", False), query=query, offset=""
+            ),
+        )
+
+        async with app:
+            await app.process_update(update)
+        assert self.test_flag == expected_result
+
     @pytest.mark.parametrize("chat_types", [[Chat.SENDER], [Chat.SENDER, Chat.SUPERGROUP], []])
     @pytest.mark.parametrize(
         ("chat_type", "result"), [(Chat.SENDER, True), (Chat.CHANNEL, False), (None, False)]