Test and document leverage strategy callback

docs/strategy-advanced.md

@@ -642,6 +642,34 @@ Freqtrade will fall back to the `proposed_stake` value should your code raise an
 !!! Tip
     Returning `0` or `None` will prevent trades from being placed.
 
+## Leverage Callback
+
+When trading in markets that allow leverage, this method must return the desired Leverage (Defaults to 1 -> No leverage).
+
+Assuming a capital of 500USDT, a trade with leverage=3 would result in a position with 500 x 3 = 1500 USDT.
+
+Values that are above `max_leverage` will be adjusted to `max_leverage`.
+For markets / exchanges that don't support leverage, this method is ignored.
+
+``` python
+class AwesomeStrategy(IStrategy):
+    def leverage(self, pair: str, current_time: 'datetime', current_rate: float,
+                 proposed_leverage: float, max_leverage: float, side: str,
+                 **kwargs) -> float:
+        """
+        Customize leverage for each new trade.
+
+        :param pair: Pair that's currently analyzed
+        :param current_time: datetime object, containing the current datetime
+        :param current_rate: Rate, calculated based on pricing settings in ask_strategy.
+        :param proposed_leverage: A leverage proposed by the bot.
+        :param max_leverage: Max leverage allowed on this pair
+        :param side: 'long' or 'short' - indicating the direction of the proposed trade
+        :return: A leverage amount, which is between 1.0 and max_leverage.
+        """
+        return 1.0
+```
+
 ---
 
 ## Derived strategies

freqtrade/strategy/interface.py

@@ -370,8 +370,7 @@ class IStrategy(ABC, HyperStrategyMixin):
                             proposed_stake: float, min_stake: float, max_stake: float,
                             **kwargs) -> float:
         """
-        Customize stake size for each new trade. This method is not called when edge module is
+        Customize stake size for each new trade.
-        enabled.
 
         :param pair: Pair that's currently analyzed
         :param current_time: datetime object, containing the current datetime
@@ -383,6 +382,23 @@ class IStrategy(ABC, HyperStrategyMixin):
         """
         return proposed_stake
 
+    def leverage(self, pair: str, current_time: datetime, current_rate: float,
+                 proposed_leverage: float, max_leverage: float, side: str,
+                 **kwargs) -> float:
+        """
+        Customize leverage for each new trade. This method is not called when edge module is
+        enabled.
+
+        :param pair: Pair that's currently analyzed
+        :param current_time: datetime object, containing the current datetime
+        :param current_rate: Rate, calculated based on pricing settings in ask_strategy.
+        :param proposed_leverage: A leverage proposed by the bot.
+        :param max_leverage: Max leverage allowed on this pair
+        :param side: 'long' or 'short' - indicating the direction of the proposed trade
+        :return: A leverage amount, which is between 1.0 and max_leverage.
+        """
+        return 1.0
+
     def informative_pairs(self) -> ListPairsWithTimeframes:
         """
         Define additional, informative pair/interval combinations to be cached from the exchange.
@@ -971,20 +987,3 @@ class IStrategy(ABC, HyperStrategyMixin):
             if 'exit_long' not in df.columns:
                 df = df.rename({'sell': 'exit_long'}, axis='columns')
             return df
-
-    def leverage(self, pair: str, current_time: datetime, current_rate: float,
-                 proposed_leverage: float, max_leverage: float, side: str,
-                 **kwargs) -> float:
-        """
-        Customize leverage for each new trade. This method is not called when edge module is
-        enabled.
-
-        :param pair: Pair that's currently analyzed
-        :param current_time: datetime object, containing the current datetime
-        :param current_rate: Rate, calculated based on pricing settings in ask_strategy.
-        :param proposed_leverage: A leverage proposed by the bot.
-        :param max_leverage: Max leverage allowed on this pair
-        :param side: 'long' or 'short' - indicating the direction of the proposed trade
-        :return: A leverage amount, which is between 1.0 and max_leverage.
-        """
-        return 1.0

tests/conftest.py

@@ -36,6 +36,7 @@ logging.getLogger('').setLevel(logging.INFO)
 np.seterr(all='raise')
 
 CURRENT_TEST_STRATEGY = 'StrategyTestV3'
+TRADE_SIDES = ('long', 'short')
 
 
 def pytest_addoption(parser):

tests/strategy/strats/strategy_test_v3.py

@@ -1,5 +1,6 @@
 # pragma pylint: disable=missing-docstring, invalid-name, pointless-string-statement
 
+from datetime import datetime
 import talib.abstract as ta
 from pandas import DataFrame
 
@@ -159,3 +160,11 @@ class StrategyTestV3(IStrategy):
 
         # TODO-lev: Add short logic
         return dataframe
+
+    def leverage(self, pair: str, current_time: datetime, current_rate: float,
+                 proposed_leverage: float, max_leverage: float, side: str,
+                 **kwargs) -> float:
+        # Return 3.0 in all cases.
+        # Bot-logic must make sure it's an allowed leverage and eventually adjust accordingly.
+
+        return 3.0

tests/strategy/test_interface.py

@@ -21,7 +21,7 @@ from freqtrade.strategy.hyper import (BaseParameter, BooleanParameter, Categoric
                                       DecimalParameter, IntParameter, RealParameter)
 from freqtrade.strategy.interface import SellCheckTuple
 from freqtrade.strategy.strategy_wrapper import strategy_safe_wrapper
-from tests.conftest import log_has, log_has_re
+from tests.conftest import CURRENT_TEST_STRATEGY, TRADE_SIDES, log_has, log_has_re
 
 from .strats.strategy_test_v3 import StrategyTestV3
 
@@ -506,6 +506,32 @@ def test_custom_sell(default_conf, fee, caplog) -> None:
     assert log_has_re('Custom sell reason returned from custom_sell is too long.*', caplog)
 
 
+@pytest.mark.parametrize('side', TRADE_SIDES)
+def test_leverage_callback(default_conf, side) -> None:
+    default_conf['strategy'] = 'StrategyTestV2'
+    strategy = StrategyResolver.load_strategy(default_conf)
+
+    assert strategy.leverage(
+        pair='XRP/USDT',
+        current_time=datetime.now(timezone.utc),
+        current_rate=2.2,
+        proposed_leverage=1.0,
+        max_leverage=5.0,
+        side=side,
+        ) == 1
+
+    default_conf['strategy'] = CURRENT_TEST_STRATEGY
+    strategy = StrategyResolver.load_strategy(default_conf)
+    assert strategy.leverage(
+        pair='XRP/USDT',
+        current_time=datetime.now(timezone.utc),
+        current_rate=2.2,
+        proposed_leverage=1.0,
+        max_leverage=5.0,
+        side=side,
+        ) == 3
+
+
 def test_analyze_ticker_default(ohlcv_history, mocker, caplog) -> None:
     caplog.set_level(logging.DEBUG)
     ind_mock = MagicMock(side_effect=lambda x, meta: x)