Mock ccxt.exchange.has as property instead of method for tests.

freqtrade/exchange/__init__.py

@@ -210,7 +210,7 @@ def get_ticker(pair: str, refresh: Optional[bool] = True) -> dict:
 
 @cached(TTLCache(maxsize=100, ttl=30))
 def get_ticker_history(pair: str, tick_interval: str) -> List[Dict]:
-    if not _API.hasFetchOHLCV():
+    if 'fetchOHLCV' not in _API.has or not _API.has['fetchOHLCV']:
         raise OperationalException(
             'Exhange {} does not support fetching historical candlestick data.'.format(_API.name)
         )

freqtrade/tests/exchange/test_exchange.py

@@ -313,7 +313,8 @@ def test_get_ticker_history(default_conf, mocker):
             5,  # volume (in quote currency)
         ]
     ]
-    api_mock.hasFetchOHLVC = MagicMock(return_value=True)
+    has = PropertyMock(return_value={'fetchOHLCV': True})
+    type(api_mock).has = has
     api_mock.fetch_ohlcv = MagicMock(return_value=tick)
     mocker.patch('freqtrade.exchange._API', api_mock)