From f92d47a16bb61fc9631b0cac29cb63b68cab25f3 Mon Sep 17 00:00:00 2001
From: Sam Germain <sam.germain@usask.ca>
Date: Fri, 31 Dec 2021 05:28:25 -0600
Subject: [PATCH] exchange._contracts_to_amount and
 exchange._amount_to_contracts safe checks

---
 freqtrade/exchange/exchange.py  | 12 ++++++++++--
 tests/exchange/test_exchange.py | 28 ++++++++++++++++++++++++++--
 2 files changed, 36 insertions(+), 4 deletions(-)

diff --git a/freqtrade/exchange/exchange.py b/freqtrade/exchange/exchange.py
index 1f395b014..cdb6de52a 100644
--- a/freqtrade/exchange/exchange.py
+++ b/freqtrade/exchange/exchange.py
@@ -875,15 +875,23 @@ class Exchange:
 
     def _amount_to_contracts(self, pair: str, amount: float):
 
+        contract_size = None
         if ('contractSize' in self.markets[pair]):
-            return amount / self.markets[pair]['contractSize']
+            contract_size = self.markets[pair]['contractSize']
+
+        if (contract_size and self.trading_mode == TradingMode.FUTURES):
+            return amount / contract_size
         else:
             return amount
 
     def _contracts_to_amount(self, pair: str, num_contracts: float):
 
+        contract_size = None
         if ('contractSize' in self.markets[pair]):
-            return num_contracts * self.markets[pair]['contractSize']
+            contract_size = self.markets[pair]['contractSize']
+
+        if (contract_size and self.trading_mode == TradingMode.FUTURES):
+            return num_contracts * contract_size
         else:
             return num_contracts
 
diff --git a/tests/exchange/test_exchange.py b/tests/exchange/test_exchange.py
index 429ba153f..94aee0e14 100644
--- a/tests/exchange/test_exchange.py
+++ b/tests/exchange/test_exchange.py
@@ -3897,6 +3897,7 @@ def test__trades_contracts_to_amount(
 @pytest.mark.parametrize('pair,param_amount,param_size', [
     ('XLTCUSDT', 40, 4000),
     ('LTC/ETH', 30, 30),
+    ('LTC/USD', 30, 30),
     ('ETH/USDT:USDT', 10, 1),
 ])
 def test__amount_to_contracts(
@@ -3908,9 +3909,32 @@ def test__amount_to_contracts(
     param_size
 ):
     api_mock = MagicMock()
-    default_conf['trading_mode'] = 'futures'
+    default_conf['trading_mode'] = 'spot'
     default_conf['collateral'] = 'isolated'
-    mocker.patch('freqtrade.exchange.Exchange.markets', markets)
+    mocker.patch('freqtrade.exchange.Exchange.markets', {
+        'LTC/USD': {
+            'symbol': 'LTC/USD',
+            'contractSize': None,
+        },
+        'XLTCUSDT': {
+            'symbol': 'XLTCUSDT',
+            'contractSize': 0.01,
+        },
+        'LTC/ETH': {
+            'symbol': 'LTC/ETH',
+        },
+        'ETH/USDT:USDT': {
+            'symbol': 'ETH/USDT:USDT',
+            'contractSize': 10,
+        }
+    })
+    exchange = get_patched_exchange(mocker, default_conf, api_mock)
+    result_size = exchange._amount_to_contracts(pair, param_amount)
+    assert result_size == param_amount
+    result_amount = exchange._contracts_to_amount(pair, param_size)
+    assert result_amount == param_size
+
+    default_conf['trading_mode'] = 'futures'
     exchange = get_patched_exchange(mocker, default_conf, api_mock)
     result_size = exchange._amount_to_contracts(pair, param_amount)
     assert result_size == param_size