Merge pull request #3676 from freqtrade/stoploss_remove_unused_argument

[minor] Cleanup and exception hierarchy documentation

docs/developer.md

@@ -85,6 +85,35 @@ docker-compose exec freqtrade_develop /bin/bash
 
 ![image](https://user-images.githubusercontent.com/419355/65456522-ba671a80-de06-11e9-9598-df9ca0d8dcac.png)
 
+## ErrorHandling
+
+Freqtrade Exceptions all inherit from `FreqtradeException`.
+This general class of error should however not be used directly. Instead, multiple specialized sub-Exceptions exist.
+
+Below is an outline of exception inheritance hierarchy:
+
+```
++ FreqtradeException
+|
++---+ OperationalException
+|
++---+ DependencyException
+|   |
+|   +---+ PricingError
+|   |
+|   +---+ ExchangeError
+|       |
+|       +---+ TemporaryError
+|       |
+|       +---+ DDosProtection
+|       |
+|       +---+ InvalidOrderException
+|           |
+|           +---+ RetryableOrderError
+|
++---+ StrategyError
+```
+
 ## Modules
 
 ### Dynamic Pairlist

freqtrade/exceptions.py

@@ -29,7 +29,14 @@ class PricingError(DependencyException):
     """
 
 
-class InvalidOrderException(FreqtradeException):
+class ExchangeError(DependencyException):
+    """
+    Error raised out of the exchange.
+    Has multiple Errors to determine the appropriate error.
+    """
+
+
+class InvalidOrderException(ExchangeError):
     """
     This is returned when the order is not valid. Example:
     If stoploss on exchange order is hit, then trying to cancel the order
@@ -44,13 +51,6 @@ class RetryableOrderError(InvalidOrderException):
     """
 
 
-class ExchangeError(DependencyException):
-    """
-    Error raised out of the exchange.
-    Has multiple Errors to determine the appropriate error.
-    """
-
-
 class TemporaryError(ExchangeError):
     """
     Temporary network or exchange related error.

freqtrade/exchange/exchange.py

@@ -975,7 +975,7 @@ class Exchange:
         except ccxt.BaseError as e:
             raise OperationalException(e) from e
 
-    # Assign method to fetch_stoploss_order to allow easy overriding in other classes
+    # Assign method to cancel_stoploss_order to allow easy overriding in other classes
     cancel_stoploss_order = cancel_order
 
     def is_cancel_order_result_suitable(self, corder) -> bool:
@@ -1041,10 +1041,10 @@ class Exchange:
     @retrier
     def fetch_l2_order_book(self, pair: str, limit: int = 100) -> dict:
         """
-        get order book level 2 from exchange
+        Get L2 order book from exchange.
-
+        Can be limited to a certain amount (if supported).
-        Notes:
+        Returns a dict in the format
-        20180619: bittrex doesnt support limits -.-
+        {'asks': [price, volume], 'bids': [price, volume]}
         """
         try:
 

freqtrade/freqtradebot.py

@@ -770,7 +770,7 @@ class FreqtradeBot:
         logger.debug('Found no sell signal for %s.', trade)
         return False
 
-    def create_stoploss_order(self, trade: Trade, stop_price: float, rate: float) -> bool:
+    def create_stoploss_order(self, trade: Trade, stop_price: float) -> bool:
         """
         Abstracts creating stoploss orders from the logic.
         Handles errors and updates the trade database object.
@@ -833,14 +833,13 @@ class FreqtradeBot:
             stoploss = self.edge.stoploss(pair=trade.pair) if self.edge else self.strategy.stoploss
             stop_price = trade.open_rate * (1 + stoploss)
 
-            if self.create_stoploss_order(trade=trade, stop_price=stop_price, rate=stop_price):
+            if self.create_stoploss_order(trade=trade, stop_price=stop_price):
                 trade.stoploss_last_update = datetime.now()
                 return False
 
         # If stoploss order is canceled for some reason we add it
         if stoploss_order and stoploss_order['status'] in ('canceled', 'cancelled'):
-            if self.create_stoploss_order(trade=trade, stop_price=trade.stop_loss,
+            if self.create_stoploss_order(trade=trade, stop_price=trade.stop_loss):
-                                          rate=trade.stop_loss):
                 return False
             else:
                 trade.stoploss_order_id = None
@@ -877,8 +876,7 @@ class FreqtradeBot:
                                      f"for pair {trade.pair}")
 
                 # Create new stoploss order
-                if not self.create_stoploss_order(trade=trade, stop_price=trade.stop_loss,
+                if not self.create_stoploss_order(trade=trade, stop_price=trade.stop_loss):
-                                                  rate=trade.stop_loss):
                     logger.warning(f"Could not create trailing stoploss order "
                                    f"for pair {trade.pair}.")
 
@@ -923,7 +921,7 @@ class FreqtradeBot:
                 if not trade.open_order_id:
                     continue
                 order = self.exchange.fetch_order(trade.open_order_id, trade.pair)
-            except (ExchangeError, InvalidOrderException):
+            except (ExchangeError):
                 logger.info('Cannot query order for %s due to %s', trade, traceback.format_exc())
                 continue
 
@@ -956,7 +954,7 @@ class FreqtradeBot:
         for trade in Trade.get_open_order_trades():
             try:
                 order = self.exchange.fetch_order(trade.open_order_id, trade.pair)
-            except (DependencyException, InvalidOrderException):
+            except (ExchangeError):
                 logger.info('Cannot query order for %s due to %s', trade, traceback.format_exc())
                 continue
 

freqtrade/rpc/rpc.py

@@ -11,7 +11,7 @@ from typing import Any, Dict, List, Optional, Tuple, Union
 import arrow
 from numpy import NAN, mean
 
-from freqtrade.exceptions import (ExchangeError, InvalidOrderException,
+from freqtrade.exceptions import (ExchangeError,
                                   PricingError)
 from freqtrade.exchange import timeframe_to_minutes, timeframe_to_msecs
 from freqtrade.misc import shorten_date
@@ -555,7 +555,7 @@ class RPC:
                 try:
                     self._freqtrade.exchange.cancel_order(trade.open_order_id, trade.pair)
                     c_count += 1
-                except (ExchangeError, InvalidOrderException):
+                except (ExchangeError):
                     pass
 
             # cancel stoploss on exchange ...
@@ -565,7 +565,7 @@ class RPC:
                     self._freqtrade.exchange.cancel_stoploss_order(trade.stoploss_order_id,
                                                                    trade.pair)
                     c_count += 1
-                except (ExchangeError, InvalidOrderException):
+                except (ExchangeError):
                     pass
 
             Trade.session.delete(trade)

tests/test_freqtradebot.py

@@ -1301,7 +1301,7 @@ def test_create_stoploss_order_invalid_order(mocker, default_conf, caplog, fee,
     freqtrade.enter_positions()
     trade = Trade.query.first()
     caplog.clear()
-    freqtrade.create_stoploss_order(trade, 200, 199)
+    freqtrade.create_stoploss_order(trade, 200)
     assert trade.stoploss_order_id is None
     assert trade.sell_reason == SellType.EMERGENCY_SELL.value
     assert log_has("Unable to place a stoploss order on exchange. ", caplog)
@@ -4107,7 +4107,7 @@ def test_sync_wallet_dry_run(mocker, default_conf, ticker, fee, limit_buy_order,
 def test_cancel_all_open_orders(mocker, default_conf, fee, limit_buy_order, limit_sell_order):
     default_conf['cancel_open_orders_on_exit'] = True
     mocker.patch('freqtrade.exchange.Exchange.fetch_order',
-                 side_effect=[DependencyException(), limit_sell_order, limit_buy_order])
+                 side_effect=[ExchangeError(), limit_sell_order, limit_buy_order])
     buy_mock = mocker.patch('freqtrade.freqtradebot.FreqtradeBot.handle_cancel_buy')
     sell_mock = mocker.patch('freqtrade.freqtradebot.FreqtradeBot.handle_cancel_sell')