Move check for position for StaticPairList to init

freqtrade/pairlist/StaticPairList.py

@@ -4,7 +4,7 @@ Static Pair List provider
 Provides pair white list as it configured in config
 """
 import logging
-from typing import Dict, List
+from typing import Any, Dict, List
 
 from freqtrade.exceptions import OperationalException
 from freqtrade.pairlist.IPairList import IPairList
@@ -15,6 +15,15 @@ logger = logging.getLogger(__name__)
 
 class StaticPairList(IPairList):
 
+    def __init__(self, exchange, pairlistmanager,
+                 config: Dict[str, Any], pairlistconfig: Dict[str, Any],
+                 pairlist_pos: int) -> None:
+        super().__init__(exchange, pairlistmanager, config, pairlistconfig, pairlist_pos)
+
+        if self._pairlist_pos != 0:
+            raise OperationalException(f"{self.name} can only be used in the first position "
+                                       "in the list of Pairlist Handlers.")
+
     @property
     def needstickers(self) -> bool:
         """
@@ -48,8 +57,4 @@ class StaticPairList(IPairList):
         :param tickers: Tickers (from exchange.get_tickers()). May be cached.
         :return: new whitelist
         """
-        if self._pairlist_pos != 0:
+        return pairlist
-            raise OperationalException(f"{self.name} can only be used in the first position "
-                                       "in the list of Pairlist Handlers.")
-        else:
-            return pairlist

tests/pairlist/test_pairlist.py

@@ -313,8 +313,15 @@ def test_VolumePairList_whitelist_gen(mocker, whitelist_conf, shitcoinmarkets, t
     whitelist_conf['stake_currency'] = base_currency
 
     mocker.patch('freqtrade.exchange.Exchange.exchange_has', MagicMock(return_value=True))
-    freqtrade = get_patched_freqtradebot(mocker, whitelist_conf)
 
+    if whitelist_result == 'static_in_the_middle':
+        with pytest.raises(OperationalException,
+                           match=r"StaticPairList can only be used in the first position "
+                                 r"in the list of Pairlist Handlers."):
+            freqtrade = get_patched_freqtradebot(mocker, whitelist_conf)
+        return
+
+    freqtrade = get_patched_freqtradebot(mocker, whitelist_conf)
     mocker.patch.multiple('freqtrade.exchange.Exchange',
                           get_tickers=tickers,
                           markets=PropertyMock(return_value=shitcoinmarkets),
@@ -326,11 +333,6 @@ def test_VolumePairList_whitelist_gen(mocker, whitelist_conf, shitcoinmarkets, t
                            match=r"This Pairlist Handler should not be used at the first position "
                                  r"in the list of Pairlist Handlers."):
             freqtrade.pairlists.refresh_pairlist()
-    elif whitelist_result == 'static_in_the_middle':
-        with pytest.raises(OperationalException,
-                           match=r"StaticPairList can only be used in the first position "
-                                 r"in the list of Pairlist Handlers."):
-            freqtrade.pairlists.refresh_pairlist()
     else:
         freqtrade.pairlists.refresh_pairlist()
         whitelist = freqtrade.pairlists.whitelist