cleanedup backtesting

https://stackoverflow.com/questions/41516287/python-del-does-not-work-as-destructor

freqtrade/optimize/backtesting.py

@@ -144,6 +144,7 @@ class Backtesting:
         self.init_backtest()
 
     def __del__(self):
+        logger.info('Inside Backtesting.__del__()')
         self.cleanup()
 
     @staticmethod
@@ -151,6 +152,7 @@ class Backtesting:
         LoggingMixin.show_output = True
         PairLocks.use_db = True
         Trade.use_db = True
+        logger.info('Cleaned Backtest')
 
     def init_backtest_detail(self):
         # Load detail timeframe if specified

freqtrade/rpc/api_server/api_backtest.py

@@ -172,6 +172,7 @@ def api_delete_backtest(ws_mode=Depends(is_webserver_mode)):
             "status_msg": "Backtest running",
         }
     if ApiServer._bt:
+        ApiServer._bt.cleanup()
         del ApiServer._bt
         ApiServer._bt = None
         del ApiServer._bt_data

tests/conftest.py

@@ -33,6 +33,12 @@ from tests.conftest_trades_usdt import (mock_trade_usdt_1, mock_trade_usdt_2, mo
 logging.getLogger('').setLevel(logging.INFO)
 
 
+@pytest.fixture(autouse=True)
+def run_around_tests():
+    yield
+    assert Trade.use_db
+
+
 # Do not mask numpy errors as warnings that no one read, raise the exсeption
 np.seterr(all='raise')