Enhance trade to verify #10166

freqtrade/optimize/backtesting.py

@@ -778,6 +778,7 @@ class Backtesting:
                 t = self._get_exit_for_signal(trade, row, exit_, current_time)
                 if t:
                     return t
+        return None
 
     def _run_funding_fees(self, trade: LocalTrade, current_time: datetime, force: bool = False):
         """

tests/optimize/test_backtesting_adjust_position.py

@@ -213,3 +213,8 @@ def test_backtest_position_adjustment_detailed(default_conf, fee, mocker, levera
     assert trade.nr_of_successful_entries == 2
     assert trade.nr_of_successful_exits == 1
     assert pytest.approx(trade.liquidation_price) == liq_price
+
+    # Adjust to close trade
+    backtesting.strategy.adjust_trade_position = MagicMock(return_value=-trade.stake_amount)
+    trade = backtesting._get_adjust_trade_entry_for_candle(trade, row_exit, current_time)
+    assert trade.is_open is False