fix: don't try to close closed cursors (#498)

Author: betodealmeida

google/cloud/bigquery/dbapi/connection.py

@@ -76,7 +76,8 @@ def close(self):
  self._bqstorage_client._transport.grpc_channel.close()
 
  for cursor_ in self._cursors_created:
- cursor_.close()
+ if not cursor_._closed:
+ cursor_.close()
 
  def commit(self):
  """No-op, but for consistency raise an error if connection is closed."""

tests/unit/test_dbapi_connection.py

@@ -176,6 +176,22 @@ def test_close_closes_all_created_cursors(self):
  self.assertTrue(cursor_1._closed)
  self.assertTrue(cursor_2._closed)
 
+ def test_close_closes_only_open_created_cursors(self):
+ connection = self._make_one(client=self._mock_client())
+ cursor_1 = connection.cursor()
+ cursor_2 = connection.cursor()
+ self.assertFalse(cursor_1._closed)
+ self.assertFalse(cursor_2._closed)
+
+ cursor_1.close()
+ self.assertTrue(cursor_1._closed)
+ cursor_1.close = mock.MagicMock()
+
+ connection.close()
+
+ self.assertFalse(cursor_1.close.called)
+ self.assertTrue(cursor_2._closed)
+
  def test_does_not_keep_cursor_instances_alive(self):
  from google.cloud.bigquery.dbapi import Cursor