Add cleanup to be called when future is garbage collected

bravado/http_future.py

@@ -90,6 +90,11 @@ def _raise_connection_error(self, exception):
         # type: (BaseException) -> typing.NoReturn
         self._raise_error(BravadoConnectionError, 'ConnectionError', exception)
 
+    def cleanup(self):
+        # type: () -> None
+        """Perform any cleanup necessary to avoid resource leaks."""
+        pass
+
     def result(self, timeout=None):
         # type: (typing.Optional[float]) -> T
         """
@@ -285,6 +290,11 @@ def cancel(self):
         # type: () -> None
         return self.future.cancel()
 
+    def __del__(self):
+        # type: () -> None
+        # Call cleanup to avoid resource leaks
+        self.future.cleanup()
+
     @reraise_errors
     def _get_incoming_response(self, timeout=None):
         # type: (typing.Optional[float]) -> IncomingResponse

tests/http_future/HttpFuture/cleanup_test.py

@@ -0,0 +1,10 @@
+# -*- coding: utf-8 -*-
+from unittest import mock
+
+from bravado.http_future import HttpFuture
+
+
+def test_cleanup_on_gc(mock_future_adapter):
+    http_future = HttpFuture(future=mock_future_adapter, response_adapter=mock.Mock())
+    del http_future
+    assert mock_future_adapter.cleanup.call_count == 1