Merge pull request #6045 from freqtrade/trade_fee_fallback_value

Add unknown_fee_rate parameter

docs/configuration.md

@@ -135,6 +135,7 @@ Mandatory parameters are marked as **Required**, which means that they are requi
 | `exchange.markets_refresh_interval` | The interval in minutes in which markets are reloaded. <br>*Defaults to `60` minutes.* <br> **Datatype:** Positive Integer
 | `exchange.skip_pair_validation` | Skip pairlist validation on startup.<br>*Defaults to `false`<br> **Datatype:** Boolean
 | `exchange.skip_open_order_update` | Skips open order updates on startup should the exchange cause problems. Only relevant in live conditions.<br>*Defaults to `false`<br> **Datatype:** Boolean
+| `exchange.unknown_fee_rate` | Fallback value to use when calculating trading fees. This can be useful for exchanges which have fees in non-tradable currencies. The value provided here will be multiplied with the "fee cost".<br>*Defaults to `None`<br> **Datatype:** float
 | `exchange.log_responses` | Log relevant exchange responses. For debug mode only - use with care.<br>*Defaults to `false`<br> **Datatype:** Boolean
 | `edge.*` | Please refer to [edge configuration document](edge.md) for detailed explanation.
 | `experimental.block_bad_exchanges` | Block exchanges known to not work with freqtrade. Leave on default unless you want to test if that exchange works now. <br>*Defaults to `true`.* <br> **Datatype:** Boolean

docs/exchanges.md

@@ -199,6 +199,11 @@ OKEX requires a passphrase for each api key, you will therefore need to add this
 !!! Warning
     OKEX only provides 100 candles per api call. Therefore, the strategy will only have a pretty low amount of data available in backtesting mode.
 
+## Gate.io
+
+Gate.io allows the use of `POINT` to pay for fees. As this is not a tradable currency (no regular market available), automatic fee calculations will fail (and default to a fee of 0).
+The configuration parameter `exchange.unknown_fee_rate` can be used to specify the exchange rate between Point and the stake currency. Obviously, changing the stake-currency will also require changes to this value.
+
 ## All exchanges
 
 Should you experience constant errors with Nonce (like `InvalidNonce`), it is best to regenerate the API keys. Resetting Nonce is difficult and it's usually easier to regenerate the API keys.

freqtrade/constants.py

@@ -395,6 +395,7 @@ CONF_SCHEMA = {
                     },
                     'uniqueItems': True
                 },
+                'unknown_fee_rate': {'type': 'number'},
                 'outdated_offset': {'type': 'integer', 'minimum': 1},
                 'markets_refresh_interval': {'type': 'integer'},
                 'ccxt_config': {'type': 'object'},

freqtrade/exchange/exchange.py

@@ -1194,9 +1194,11 @@ class Exchange:
                 tick = self.fetch_ticker(comb)
 
                 fee_to_quote_rate = safe_value_fallback2(tick, tick, 'last', 'ask')
-                return round((order['fee']['cost'] * fee_to_quote_rate) / order['cost'], 8)
             except ExchangeError:
-                return None
+                fee_to_quote_rate = self._config['exchange'].get('unknown_fee_rate', None)
+                if not fee_to_quote_rate:
+                    return None
+            return round((order['fee']['cost'] * fee_to_quote_rate) / order['cost'], 8)
 
     def extract_cost_curr_rate(self, order: Dict) -> Tuple[float, str, Optional[float]]:
         """

tests/exchange/test_exchange.py

@@ -2948,39 +2948,49 @@ def test_extract_cost_curr_rate(mocker, default_conf, order, expected) -> None:
     assert ex.extract_cost_curr_rate(order) == expected
 
 
-@pytest.mark.parametrize("order,expected", [
+@pytest.mark.parametrize("order,unknown_fee_rate,expected", [
     # Using base-currency
     ({'symbol': 'ETH/BTC', 'amount': 0.04, 'cost': 0.05,
-        'fee': {'currency': 'ETH', 'cost': 0.004, 'rate': None}}, 0.1),
+        'fee': {'currency': 'ETH', 'cost': 0.004, 'rate': None}}, None, 0.1),
     ({'symbol': 'ETH/BTC', 'amount': 0.05, 'cost': 0.05,
-        'fee': {'currency': 'ETH', 'cost': 0.004, 'rate': None}}, 0.08),
+        'fee': {'currency': 'ETH', 'cost': 0.004, 'rate': None}}, None, 0.08),
     # Using quote currency
     ({'symbol': 'ETH/BTC', 'amount': 0.04, 'cost': 0.05,
-        'fee': {'currency': 'BTC', 'cost': 0.005}}, 0.1),
+        'fee': {'currency': 'BTC', 'cost': 0.005}}, None, 0.1),
     ({'symbol': 'ETH/BTC', 'amount': 0.04, 'cost': 0.05,
-        'fee': {'currency': 'BTC', 'cost': 0.002, 'rate': None}}, 0.04),
+        'fee': {'currency': 'BTC', 'cost': 0.002, 'rate': None}}, None, 0.04),
     # Using foreign currency
     ({'symbol': 'ETH/BTC', 'amount': 0.04, 'cost': 0.05,
-        'fee': {'currency': 'NEO', 'cost': 0.0012}}, 0.001944),
+        'fee': {'currency': 'NEO', 'cost': 0.0012}}, None, 0.001944),
     ({'symbol': 'ETH/BTC', 'amount': 2.21, 'cost': 0.02992561,
-        'fee': {'currency': 'NEO', 'cost': 0.00027452}}, 0.00074305),
+        'fee': {'currency': 'NEO', 'cost': 0.00027452}}, None, 0.00074305),
     # 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),
+        'fee': {'currency': 'USDT', 'cost': 0.34, 'rate': 0.01}}, None, 0.01),
     ({'symbol': 'ETH/BTC', 'amount': 0.04, 'cost': 0.05,
-        'fee': {'currency': 'USDT', 'cost': 0.34, 'rate': 0.005}}, 0.005),
+        'fee': {'currency': 'USDT', 'cost': 0.34, 'rate': 0.005}}, None, 0.005),
     # 0.1% filled - no costs (kraken - #3431)
     ({'symbol': 'ETH/BTC', 'amount': 0.04, 'cost': 0.0,
-      'fee': {'currency': 'BTC', 'cost': 0.0, 'rate': None}}, None),
+      'fee': {'currency': 'BTC', 'cost': 0.0, 'rate': None}}, None, None),
     ({'symbol': 'ETH/BTC', 'amount': 0.04, 'cost': 0.0,
-      'fee': {'currency': 'ETH', 'cost': 0.0, 'rate': None}}, 0.0),
+      'fee': {'currency': 'ETH', 'cost': 0.0, 'rate': None}}, None, 0.0),
     ({'symbol': 'ETH/BTC', 'amount': 0.04, 'cost': 0.0,
-      'fee': {'currency': 'NEO', 'cost': 0.0, 'rate': None}}, None),
+      'fee': {'currency': 'NEO', 'cost': 0.0, 'rate': None}}, None, None),
+    # Invalid pair combination - POINT/BTC is not a pair
+    ({'symbol': 'POINT/BTC', 'amount': 0.04, 'cost': 0.5,
+      'fee': {'currency': 'POINT', 'cost': 2.0, 'rate': None}}, None, None),
+    ({'symbol': 'POINT/BTC', 'amount': 0.04, 'cost': 0.5,
+      'fee': {'currency': 'POINT', 'cost': 2.0, 'rate': None}}, 1, 4.0),
+    ({'symbol': 'POINT/BTC', 'amount': 0.04, 'cost': 0.5,
+      'fee': {'currency': 'POINT', 'cost': 2.0, 'rate': None}}, 2, 8.0),
 ])
-def test_calculate_fee_rate(mocker, default_conf, order, expected) -> None:
+def test_calculate_fee_rate(mocker, default_conf, order, expected, unknown_fee_rate) -> None:
     mocker.patch('freqtrade.exchange.Exchange.fetch_ticker', return_value={'last': 0.081})
+    if unknown_fee_rate:
+        default_conf['exchange']['unknown_fee_rate'] = unknown_fee_rate
 
     ex = get_patched_exchange(mocker, default_conf)
+
     assert ex.calculate_fee_rate(order) == expected