From 75446d8195b58b2b4180a65d81f7452868a698c1 Mon Sep 17 00:00:00 2001
From: hroff-1902 <hroff_raeyd9tzpttf@mail.ru>
Date: Sun, 29 Sep 2019 23:08:11 +0300
Subject: [PATCH] Refactor list-timeframes command with the use of the Exchange
 class methods

---
 freqtrade/exchange/exchange.py  | 18 ++++++++++--------
 freqtrade/utils.py              | 17 ++++++-----------
 tests/exchange/test_exchange.py |  3 ++-
 3 files changed, 18 insertions(+), 20 deletions(-)

diff --git a/freqtrade/exchange/exchange.py b/freqtrade/exchange/exchange.py
index e2819bb59..6d68cef87 100644
--- a/freqtrade/exchange/exchange.py
+++ b/freqtrade/exchange/exchange.py
@@ -133,6 +133,9 @@ class Exchange:
 
         logger.info('Using Exchange "%s"', self.name)
 
+        # Check if timeframe is available
+        self.validate_timeframes(config.get('ticker_interval'))
+
         # Converts the interval provided in minutes in config to seconds
         self.markets_refresh_interval: int = exchange_config.get(
             "markets_refresh_interval", 60) * 60
@@ -144,10 +147,6 @@ class Exchange:
         self.validate_ordertypes(config.get('order_types', {}))
         self.validate_order_time_in_force(config.get('order_time_in_force', {}))
 
-        if config.get('ticker_interval'):
-            # Check if timeframe is available
-            self.validate_timeframes(config['ticker_interval'])
-
     def __del__(self):
         """
         Destructor - clean up async stuff
@@ -199,6 +198,10 @@ class Exchange:
         """exchange ccxt id"""
         return self._api.id
 
+    @property
+    def timeframes(self) -> List[str]:
+        return list((self._api.timeframes or {}).keys())
+
     @property
     def markets(self) -> Dict:
         """exchange ccxt markets"""
@@ -291,7 +294,7 @@ class Exchange:
                 return pair
         raise DependencyException(f"Could not combine {curr_1} and {curr_2} to get a valid pair.")
 
-    def validate_timeframes(self, timeframe: List[str]) -> None:
+    def validate_timeframes(self, timeframe: Optional[str]) -> None:
         """
         Checks if ticker interval from config is a supported timeframe on the exchange
         """
@@ -304,10 +307,9 @@ class Exchange:
                 f"for the exchange \"{self.name}\" and this exchange "
                 f"is therefore not supported. ccxt fetchOHLCV: {self.exchange_has('fetchOHLCV')}")
 
-        timeframes = self._api.timeframes
-        if timeframe not in timeframes:
+        if timeframe and (timeframe not in self.timeframes):
             raise OperationalException(
-                f'Invalid ticker {timeframe}, this Exchange supports {timeframes}')
+                f"Invalid ticker interval '{timeframe}'. This exchange supports: {self.timeframes}")
 
     def validate_ordertypes(self, order_types: Dict) -> None:
         """
diff --git a/freqtrade/utils.py b/freqtrade/utils.py
index 559fef0a5..1f297b7ac 100644
--- a/freqtrade/utils.py
+++ b/freqtrade/utils.py
@@ -104,19 +104,14 @@ def start_list_timeframes(args: Dict[str, Any]) -> None:
     Print ticker intervals (timeframes) available on Exchange
     """
     config = setup_utils_configuration(args, RunMode.OTHER)
+    # Do not use ticker_interval set in the config
+    config['ticker_interval'] = None
 
     # Init exchange
     exchange = ExchangeResolver(config['exchange']['name'], config).exchange
 
-    timeframes = list((exchange._api.timeframes or {}).keys())
-
-    if not timeframes:
-        logger.warning("List of timeframes available for exchange "
-                       f"`{config['exchange']['name']}` is empty. "
-                       "This exchange does not support fetching OHLCV data.")
+    if args['print_one_column']:
+        print('\n'.join(exchange.timeframes))
     else:
-        if args['print_one_column']:
-            print('\n'.join(timeframes))
-        else:
-            print(f"Timeframes available for the exchange `{config['exchange']['name']}`: "
-                  f"{', '.join(timeframes)}")
+        print(f"Timeframes available for the exchange `{config['exchange']['name']}`: "
+              f"{', '.join(exchange.timeframes)}")
diff --git a/tests/exchange/test_exchange.py b/tests/exchange/test_exchange.py
index f8c556aeb..bf6025322 100644
--- a/tests/exchange/test_exchange.py
+++ b/tests/exchange/test_exchange.py
@@ -409,7 +409,8 @@ def test_validate_timeframes_failed(default_conf, mocker):
     mocker.patch('freqtrade.exchange.Exchange._init_ccxt', MagicMock(return_value=api_mock))
     mocker.patch('freqtrade.exchange.Exchange._load_markets', MagicMock(return_value={}))
     mocker.patch('freqtrade.exchange.Exchange.validate_pairs', MagicMock())
-    with pytest.raises(OperationalException, match=r'Invalid ticker 3m, this Exchange supports.*'):
+    with pytest.raises(OperationalException,
+                       match=r"Invalid ticker interval '3m'. This exchange supports.*"):
         Exchange(default_conf)