Add tests and test-strategies for custom "implements" requirements

freqtrade/resolvers/strategy_resolver.py

@@ -227,7 +227,7 @@ class StrategyResolver(IResolver):
                 if type(strategy).populate_exit_trend == IStrategy.populate_exit_trend:
                     raise OperationalException("`populate_exit_trend` must be implemented.")
             else:
-
+                # TODO: Implementing buy_trend and sell_trend should raise a deprecation.
                 if (type(strategy).populate_buy_trend == IStrategy.populate_buy_trend
                         and type(strategy).populate_entry_trend == IStrategy.populate_entry_trend):
                     raise OperationalException(

tests/strategy/strats/broken_strats/broken_futures_strategies.py

@@ -0,0 +1,16 @@
+# The strategy which fails to load due to non-existent dependency
+
+from pandas import DataFrame
+
+from freqtrade.strategy.interface import IStrategy
+
+
+class TestStrategyNoImplements(IStrategy):
+
+    def populate_indicators(self, dataframe: DataFrame, metadata: dict) -> DataFrame:
+        return super().populate_indicators(dataframe, metadata)
+
+
+class TestStrategyNoImplementSell(TestStrategyNoImplements):
+    def populate_entry_trend(self, dataframe: DataFrame, metadata: dict) -> DataFrame:
+        return super().populate_entry_trend(dataframe, metadata)

tests/strategy/test_strategy_loading.py

@@ -391,6 +391,32 @@ def test_deprecate_populate_indicators(result, default_conf):
             in str(w[-1].message)
 
 
+@pytest.mark.filterwarnings("ignore:deprecated")
+def test_missing_implements(result, default_conf):
+    default_location = Path(__file__).parent / "strats/broken_strats"
+    default_conf.update({'strategy': 'TestStrategyNoImplements',
+                         'strategy_path': default_location})
+    with pytest.raises(OperationalException,
+                       match=r"`populate_entry_trend` or `populate_buy_trend`.*"):
+        StrategyResolver.load_strategy(default_conf)
+
+    default_conf['strategy'] = 'TestStrategyNoImplementSell'
+
+    with pytest.raises(OperationalException,
+                       match=r"`populate_exit_trend` or `populate_sell_trend`.*"):
+        StrategyResolver.load_strategy(default_conf)
+
+    default_conf['trading_mode'] = 'futures'
+
+    with pytest.raises(OperationalException,
+                       match=r"`populate_exit_trend` must be implemented.*"):
+        StrategyResolver.load_strategy(default_conf)
+
+    default_conf['strategy'] = 'TestStrategyNoImplements'
+    with pytest.raises(OperationalException,
+                       match=r"`populate_entry_trend` must be implemented.*"):
+        StrategyResolver.load_strategy(default_conf)
+
 @pytest.mark.filterwarnings("ignore:deprecated")
 def test_call_deprecated_function(result, default_conf, caplog):
     default_location = Path(__file__).parent / "strats"