fix #3463 by explicitly failing if no stoploss is defined

freqtrade/pairlist/PrecisionFilter.py

@@ -5,7 +5,7 @@ import logging
 from typing import Any, Dict
 
 from freqtrade.pairlist.IPairList import IPairList
-
+from freqtrade.exceptions import OperationalException
 
 logger = logging.getLogger(__name__)
 
@@ -17,6 +17,10 @@ class PrecisionFilter(IPairList):
                  pairlist_pos: int) -> None:
         super().__init__(exchange, pairlistmanager, config, pairlistconfig, pairlist_pos)
 
+        if 'stoploss' not in self._config:
+            raise OperationalException(
+                'PrecisionFilter can only work with stoploss defined. Please add the '
+                'stoploss key to your configuration (overwrites eventual strategy settings).')
         self._stoploss = self._config['stoploss']
         self._enabled = self._stoploss != 0
 

tests/pairlist/test_pairlist.py

@@ -362,6 +362,17 @@ def test_VolumePairList_whitelist_gen(mocker, whitelist_conf, shitcoinmarkets, t
                     assert not log_has(logmsg, caplog)
 
 
+def test_PrecisionFilter_error(mocker, whitelist_conf, tickers) -> None:
+    whitelist_conf['pairlists'] = [{"method": "StaticPairList"}, {"method": "PrecisionFilter"}]
+    del whitelist_conf['stoploss']
+
+    mocker.patch('freqtrade.exchange.Exchange.exchange_has', MagicMock(return_value=True))
+
+    with pytest.raises(OperationalException,
+                       match=r"PrecisionFilter can only work with stoploss defined\..*"):
+        PairListManager(MagicMock, whitelist_conf)
+
+
 def test_gen_pair_whitelist_not_supported(mocker, default_conf, tickers) -> None:
     default_conf['pairlists'] = [{'method': 'VolumePairList', 'number_assets': 10}]