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Implement fee rate calculation

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This commit is contained in:
Matthias 2020-05-01 15:17:52 +02:00
parent 45c97fde2d
commit 59bafc8d02
2 changed files with 69 additions and 9 deletions
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33
freqtrade/exchange/exchange.py
View File

@ -22,7 +22,7 @@ from freqtrade.data.converter import ohlcv_to_dataframe
from freqtrade.exceptions import (DependencyException, InvalidOrderException,
OperationalException, TemporaryError)
from freqtrade.exchange.common import BAD_EXCHANGES, retrier, retrier_async
from freqtrade.misc import deep_merge_dicts
from freqtrade.misc import deep_merge_dicts, safe_value_fallback
CcxtModuleType = Any
@ -1084,8 +1084,33 @@ class Exchange:
and order['fee']['cost'] is not None
)
@staticmethod
def extract_cost_curr_rate(order: Dict) -> Tuple[float, str, Optional[float]]:
def calculate_fee_rate(self, order: Dict) -> Optional[float]:
"""
Calculate fee rate if it's not given by the exchange.
:param order: Order or trade (one trade) dict
"""
if order['fee'].get('rate') is not None:
return order['fee'].get('rate')
fee_curr = order['fee']['currency']
# Calculate fee based on order details
if fee_curr in self.get_pair_base_currency(order['symbol']):
# Base currency - divide by amount
return round(order['fee']['cost'] / order['amount'], 8)
elif fee_curr in self.get_pair_quote_currency(order['symbol']):
# Quote currency - divide by cost
return round(order['fee']['cost'] / order['cost'], 8)
else:
# If Fee currency is a different currency
try:
comb = self.get_valid_pair_combination(fee_curr, self._config['stake_currency'])
tick = self.fetch_ticker(comb)
fee_to_quote_rate = safe_value_fallback(tick, tick, 'last', 'ask')
return round((order['fee']['cost'] * fee_to_quote_rate) / order['cost'], 8)
except DependencyException:
return None
def extract_cost_curr_rate(self, order: Dict) -> Tuple[float, str, Optional[float]]:
"""
Extract tuple of cost, currency, rate.
Requires order_has_fee to run first!
@ -1094,7 +1119,7 @@ class Exchange:
"""
return (order['fee']['cost'],
order['fee']['currency'],
order['fee'].get('rate', None))
self.calculate_fee_rate(order))
# calculate rate ? (order['fee']['cost'] / (order['amount'] * order['price']))

45
tests/exchange/test_exchange.py
View File

@ -2159,9 +2159,44 @@ def test_order_has_fee(order, expected) -> None:
@pytest.mark.parametrize("order,expected", [
({'fee': {'currency': 'ETH/BTC', 'cost': 0.43}}, (0.43, 'ETH/BTC', None)),
({'fee': {'currency': 'ETH/USDT', 'cost': 0.01}}, (0.01, 'ETH/USDT', None)),
({'fee': {'currency': 'ETH/USDT', 'cost': 0.34, 'rate': 0.01}}, (0.34, 'ETH/USDT', 0.01)),
({'symbol': 'ETH/BTC', 'fee': {'currency': 'ETH', 'cost': 0.43}},
(0.43, 'ETH', 0.01)),
({'symbol': 'ETH/USDT', 'fee': {'currency': 'USDT', 'cost': 0.01}},
(0.01, 'USDT', 0.01)),
({'symbol': 'BTC/USDT', 'fee': {'currency': 'USDT', 'cost': 0.34, 'rate': 0.01}},
(0.34, 'USDT', 0.01)),
])
def test_extract_cost_curr_rate(order, expected) -> None:
assert Exchange.extract_cost_curr_rate(order) == expected
def test_extract_cost_curr_rate(mocker, default_conf, order, expected) -> None:
mocker.patch('freqtrade.exchange.Exchange.calculate_fee_rate', MagicMock(return_value=0.01))
ex = get_patched_exchange(mocker, default_conf)
assert ex.extract_cost_curr_rate(order) == expected
@pytest.mark.parametrize("order,expected", [
# Using base-currency
({'symbol': 'ETH/BTC', 'amount': 0.04, 'cost': 0.05,
'fee': {'currency': 'ETH', 'cost': 0.004, 'rate': None}}, 0.1),
({'symbol': 'ETH/BTC', 'amount': 0.05, 'cost': 0.05,
'fee': {'currency': 'ETH', 'cost': 0.004, 'rate': None}}, 0.08),
# Using quote currency
({'symbol': 'ETH/BTC', 'amount': 0.04, 'cost': 0.05,
'fee': {'currency': 'BTC', 'cost': 0.005}}, 0.1),
({'symbol': 'ETH/BTC', 'amount': 0.04, 'cost': 0.05,
'fee': {'currency': 'BTC', 'cost': 0.002, 'rate': None}}, 0.04),
# Using foreign currency
({'symbol': 'ETH/BTC', 'amount': 0.04, 'cost': 0.05,
'fee': {'currency': 'NEO', 'cost': 0.0012}}, 0.001944),
({'symbol': 'ETH/BTC', 'amount': 2.21, 'cost': 0.02992561,
'fee': {'currency': 'NEO', 'cost': 0.00027452}}, 0.00074305),
# TODO: More tests here!
# Rate included in return - return as is
({'symbol': 'ETH/BTC', 'amount': 0.04, 'cost': 0.05,
'fee': {'currency': 'USDT', 'cost': 0.34, 'rate': 0.01}}, 0.01),
({'symbol': 'ETH/BTC', 'amount': 0.04, 'cost': 0.05,
'fee': {'currency': 'USDT', 'cost': 0.34, 'rate': 0.005}}, 0.005),
])
def test_calculate_fee_rate(mocker, default_conf, order, expected) -> None:
mocker.patch('freqtrade.exchange.Exchange.fetch_ticker', return_value={'last': 0.081})
ex = get_patched_exchange(mocker, default_conf)
assert ex.calculate_fee_rate(order) == expected