From 06206335d95e7f5f9786e27946bd075ef8fc624e Mon Sep 17 00:00:00 2001
From: Sam Germain <sam.germain@usask.ca>
Date: Mon, 9 Aug 2021 00:00:50 -0600
Subject: [PATCH] Added tests for interest_function

---
 freqtrade/leverage/interest.py  | 21 +++++----
 tests/leverage/test_leverage.py | 75 +++++++++++++++++++++++++--------
 2 files changed, 67 insertions(+), 29 deletions(-)

diff --git a/freqtrade/leverage/interest.py b/freqtrade/leverage/interest.py
index b8bc47887..aacbb3532 100644
--- a/freqtrade/leverage/interest.py
+++ b/freqtrade/leverage/interest.py
@@ -15,20 +15,19 @@ def interest(
     rate: Decimal,
     hours: Decimal
 ) -> Decimal:
-    """Equation to calculate interest on margin trades
+    """
+        Equation to calculate interest on margin trades
 
+        :param exchange_name: The exchanged being trading on
+        :param borrowed: The amount of currency being borrowed
+        :param rate: The rate of interest
+        :param hours: The time in hours that the currency has been borrowed for
 
-    :param exchange_name: The exchanged being trading on
-    :param borrowed: The amount of currency being borrowed
-    :param rate: The rate of interest
-    :param hours: The time in hours that the currency has been borrowed for
-
-    Raises:
-        OperationalException: Raised if freqtrade does
-        not support margin trading for this exchange
-
-    Returns: The amount of interest owed (currency matches borrowed)
+        Raises:
+            OperationalException: Raised if freqtrade does
+            not support margin trading for this exchange
 
+        Returns: The amount of interest owed (currency matches borrowed)
     """
     exchange_name = exchange_name.lower()
     if exchange_name == "binance":
diff --git a/tests/leverage/test_leverage.py b/tests/leverage/test_leverage.py
index 072c08b63..963051f7d 100644
--- a/tests/leverage/test_leverage.py
+++ b/tests/leverage/test_leverage.py
@@ -1,26 +1,65 @@
-# from decimal import Decimal
+from decimal import Decimal
+
+from freqtrade.leverage import interest
+
 
-# from freqtrade.enums import Collateral, TradingMode
-# from freqtrade.leverage import interest
 # from freqtrade.exceptions import OperationalException
-# binance = "binance"
-# kraken = "kraken"
-# ftx = "ftx"
-# other = "bittrex"
+binance = "binance"
+kraken = "kraken"
+ftx = "ftx"
+other = "bittrex"
 
 
 def test_interest():
-    return
+
+    borrowed = Decimal(60.0)
+    interest_rate = Decimal(0.0005)
+    interest_rate_2 = Decimal(0.00025)
+    ten_mins = Decimal(1/6)
+    five_hours = Decimal(5.0)
+
     # Binance
-    # assert interest(binance, borrowed=60, rate=0.0005,
-    #                    hours = 1/6) == round(0.0008333333333333334, 8)
-    # TODO-lev: The below tests
-    # assert interest(binance, borrowed=60, rate=0.00025, hours=5.0) == 1.0
+    assert float(interest(
+        exchange_name=binance,
+        borrowed=borrowed,
+        rate=interest_rate,
+        hours=ten_mins
+    )) == 0.00125
 
-    # # Kraken
-    # assert interest(kraken, borrowed=60, rate=0.0005, hours=1.0) == 1.0
-    # assert interest(kraken, borrowed=60, rate=0.00025, hours=5.0) == 1.0
+    assert float(interest(
+        exchange_name=binance,
+        borrowed=borrowed,
+        rate=interest_rate_2,
+        hours=five_hours
+    )) == 0.003125
 
-    # # FTX
-    # assert interest(ftx, borrowed=60, rate=0.0005, hours=1.0) == 1.0
-    # assert interest(ftx, borrowed=60, rate=0.00025, hours=5.0) == 1.0
+    # Kraken
+    assert float(interest(
+        exchange_name=kraken,
+        borrowed=borrowed,
+        rate=interest_rate,
+        hours=ten_mins
+    )) == 0.06
+
+    assert float(interest(
+        exchange_name=kraken,
+        borrowed=borrowed,
+        rate=interest_rate_2,
+        hours=five_hours
+    )) == 0.045
+
+    # FTX
+    # TODO-lev
+    # assert float(interest(
+    #     exchange_name=ftx,
+    #     borrowed=borrowed,
+    #     rate=interest_rate,
+    #     hours=ten_mins
+    # )) == 0.00125
+
+    # assert float(interest(
+    #     exchange_name=ftx,
+    #     borrowed=borrowed,
+    #     rate=interest_rate_2,
+    #     hours=five_hours
+    # )) == 0.003125