fix(telegram): final message waits for the draft push in flight

src/beaver_gateway/frontends/telegram/drafts.py

@@ -52,6 +52,7 @@ class Draft:
         self._broken = False
         self._last_sent = 0.0
         self._task: asyncio.Task[None] | None = None
+        self._inflight: asyncio.Future[None] | None = None
 
     def start(self) -> None:
         if self._task is None:
@@ -68,17 +69,26 @@ class Draft:
             self._dirty = True
 
     async def stop(self) -> None:
+        """Stop pushing and wait for the push in flight.
+
+        The final ``sendMessage`` must reach Telegram after the last draft,
+        or the draft lands on top of the message and lingers for its 30 s.
+        """
         if self._task is None:
             return
         self._task.cancel()
         with contextlib.suppress(asyncio.CancelledError):
             await self._task
         self._task = None
+        if self._inflight is not None:
+            with contextlib.suppress(Exception):
+                await self._inflight
 
     async def _run(self) -> None:
         while not self._broken:
             if self._dirty or time.monotonic() - self._last_sent > _KEEPALIVE:
-                await self._push()
+                self._inflight = asyncio.ensure_future(self._push())
+                await asyncio.shield(self._inflight)
             await asyncio.sleep(self._interval)
 
     async def _push(self) -> None:

tests/test_telegram.py

@@ -33,6 +33,7 @@ class FakeBot:
         self.reactions: list[tuple[int, list[Any]]] = []
         self.fail_sends = 0
         self.reject_html = False
+        self.order: list[tuple[str, int | None]] = []
         self._message_id = 100
         self.session = SimpleNamespace(close=self._close)
 
@@ -64,6 +65,7 @@ class FakeBot:
                 message="Bad Request: can't parse entities",
             )
         self._message_id += 1
+        self.order.append(("message", message_thread_id))
         self.sent.append(
             {
                 "chat_id": chat_id,
@@ -77,7 +79,9 @@ class FakeBot:
         return SimpleNamespace(message_id=self._message_id)
 
     async def send_message_draft(self, **kwargs: Any) -> bool:
+        await asyncio.sleep(0.08)
         self.drafts.append(kwargs)
+        self.order.append(("draft", kwargs.get("message_thread_id")))
         return True
 
     async def create_forum_topic(self, chat_id, name, **_: Any) -> Any:
@@ -244,6 +248,9 @@ async def test_general_is_master_and_reply_has_no_thread(stack: Stack) -> None:
     )
     assert master is not None and master.kind == "master"
     assert stack.bot.drafts and stack.bot.drafts[0]["chat_id"] == USER
+    await asyncio.sleep(0.2)
+    final = max(i for i, o in enumerate(stack.bot.order) if o[0] == "message")
+    assert all(o[0] != "draft" for o in stack.bot.order[final:])
     rows = await stack.world.conversations.queue.recent(master.id)
     assert [r.origin for r in rows] == ["telegram"]