Ensure BLE device is disconnected after unhandled connect exception

aioesphomeapi/client.py

@@ -580,6 +580,7 @@ async def bluetooth_device_connect(  # pylint: disable=too-many-locals, too-many
         )
         timeout_expired = False
         connect_ok = False
+        unhandled_exception = False
         try:
             await connect_future
             connect_ok = True
@@ -606,11 +607,18 @@ async def bluetooth_device_connect(  # pylint: disable=too-many-locals, too-many
                 f"after {timeout}s, disconnect timed out: {disconnect_timed_out}, "
                 f" after {disconnect_timeout}s"
             ) from err
+        except BaseException:
+            unhandled_exception = True
+            raise
         finally:
-            if not connect_ok and not timeout_expired:
+            if unhandled_exception or (not connect_ok and not timeout_expired):
                 unsub()
             if not timeout_expired:
                 timeout_handle.cancel()
+            if unhandled_exception:
+                # Make sure to disconnect if we had an unhandled exception
+                # as otherwise the connection will be left open.
+                self._bluetooth_disconnect_no_wait(address)
 
         return unsub
 
@@ -717,6 +725,14 @@ def _raise_for_ble_connection_change(
             f"({response.error})"
         )
 
+    def _bluetooth_disconnect_no_wait(self, address: int) -> None:
+        """Disconnect from a Bluetooth device without waiting for a response."""
+        self._get_connection().send_message(
+            BluetoothDeviceRequest(
+                address=address, request_type=BluetoothDeviceRequestType.DISCONNECT
+            )
+        )
+
     async def _bluetooth_device_request(
         self,
         address: int,

tests/test_client.py

@@ -2194,6 +2194,13 @@ def on_bluetooth_connection_state(connected: bool, mtu: int, error: int) -> None
         await connect_task
     assert states == []
 
+    # Ensure the disconnect request is written
+    assert len(transport.writelines.mock_calls) == 2
+    req = BluetoothDeviceRequest(
+        address=1234, request_type=BluetoothDeviceRequestType.DISCONNECT
+    ).SerializeToString()
+    assert transport.writelines.mock_calls[-1] == call([b"\x00", b"\x05", b"D", req])
+
     handlers_after = len(list(itertools.chain(*connection._message_handlers.values())))
     # Make sure we do not leak message handlers
     assert handlers_after == handlers_before