Use FtPrecise in interest calculation

freqtrade/leverage/interest.py

@@ -1,20 +1,20 @@
-from decimal import Decimal
 from math import ceil
 
 from freqtrade.exceptions import OperationalException
+from freqtrade.util import FtPrecise
 
 
-one = Decimal(1.0)
-four = Decimal(4.0)
-twenty_four = Decimal(24.0)
+one = FtPrecise(1.0)
+four = FtPrecise(4.0)
+twenty_four = FtPrecise(24.0)
 
 
 def interest(
     exchange_name: str,
-    borrowed: Decimal,
-    rate: Decimal,
-    hours: Decimal
-) -> Decimal:
+    borrowed: FtPrecise,
+    rate: FtPrecise,
+    hours: FtPrecise
+) -> FtPrecise:
     """
     Equation to calculate interest on margin trades
 
@@ -31,13 +31,13 @@ def interest(
     """
     exchange_name = exchange_name.lower()
     if exchange_name == "binance":
-        return borrowed * rate * ceil(hours) / twenty_four
+        return borrowed * rate * FtPrecise(ceil(hours)) / twenty_four
     elif exchange_name == "kraken":
         # Rounded based on https://kraken-fees-calculator.github.io/
-        return borrowed * rate * (one + ceil(hours / four))
+        return borrowed * rate * (one + FtPrecise(ceil(hours / four)))
     elif exchange_name == "ftx":
         # As Explained under #Interest rates section in
         # https://help.ftx.com/hc/en-us/articles/360053007671-Spot-Margin-Trading-Explainer
-        return borrowed * rate * ceil(hours) / twenty_four
+        return borrowed * rate * FtPrecise(ceil(hours)) / twenty_four
     else:
         raise OperationalException(f"Leverage not available on {exchange_name} with freqtrade")

tests/leverage/test_interest.py

@@ -1,14 +1,14 @@
-from decimal import Decimal
 from math import isclose
 
 import pytest
 
 from freqtrade.leverage import interest
+from freqtrade.util import FtPrecise
 
 
-ten_mins = Decimal(1 / 6)
-five_hours = Decimal(5.0)
-twentyfive_hours = Decimal(25.0)
+ten_mins = FtPrecise(1 / 6)
+five_hours = FtPrecise(5.0)
+twentyfive_hours = FtPrecise(25.0)
 
 
 @pytest.mark.parametrize('exchange,interest_rate,hours,expected', [
@@ -28,11 +28,11 @@ twentyfive_hours = Decimal(25.0)
     ('ftx', 0.00025, twentyfive_hours, 0.015625),
 ])
 def test_interest(exchange, interest_rate, hours, expected):
-    borrowed = Decimal(60.0)
+    borrowed = FtPrecise(60.0)
 
     assert isclose(interest(
         exchange_name=exchange,
         borrowed=borrowed,
-        rate=Decimal(interest_rate),
+        rate=FtPrecise(interest_rate),
         hours=hours
     ), expected)

tests/rpc/test_rpc_apiserver.py

@@ -892,7 +892,7 @@ def test_api_performance(botclient, fee):
     assert_response(rc)
     assert len(rc.json()) == 2
     assert rc.json() == [{'count': 1, 'pair': 'LTC/ETH', 'profit': 7.61, 'profit_pct': 7.61,
-                          'profit_ratio': 0.07609203, 'profit_abs': 0.01872279},
+                          'profit_ratio': 0.07609203, 'profit_abs': 0.0187228},
                          {'count': 1, 'pair': 'XRP/ETH', 'profit': -5.57, 'profit_pct': -5.57,
                           'profit_ratio': -0.05570419, 'profit_abs': -0.1150375}]