Implement pair_to_filename to datahandler

includes tests - taken from #2744 and modified to adapt to new structure

freqtrade/data/history/jsondatahandler.py

@@ -30,7 +30,7 @@ class JsonDataHandler(IDataHandler):
         _tmp = [re.search(r'^(\S+)(?=\-' + timeframe + '.json)', p.name)
                 for p in datadir.glob(f"*{timeframe}.{cls._get_file_extension()}")]
         # Check if regex found something and only return these results
-        return [match[0].replace('_', '/') for match in _tmp if match]
+        return [misc.pair_to_filename(match[0]) for match in _tmp if match]
 
     def ohlcv_store(self, pair: str, timeframe: str, data: DataFrame) -> None:
         """
@@ -109,7 +109,7 @@ class JsonDataHandler(IDataHandler):
         _tmp = [re.search(r'^(\S+)(?=\-trades.json)', p.name)
                 for p in datadir.glob(f"*trades.{cls._get_file_extension()}")]
         # Check if regex found something and only return these results to avoid exceptions.
-        return [match[0].replace('_', '/') for match in _tmp if match]
+        return [misc.pair_to_filename(match[0]) for match in _tmp if match]
 
     def trades_store(self, pair: str, data: List[Dict]) -> None:
         """
@@ -157,7 +157,7 @@ class JsonDataHandler(IDataHandler):
 
     @classmethod
     def _pair_data_filename(cls, datadir: Path, pair: str, timeframe: str) -> Path:
-        pair_s = pair.replace("/", "_")
+        pair_s = misc.pair_to_filename(pair)
         filename = datadir.joinpath(f'{pair_s}-{timeframe}.{cls._get_file_extension()}')
         return filename
 
@@ -167,7 +167,7 @@ class JsonDataHandler(IDataHandler):
 
     @classmethod
     def _pair_trades_filename(cls, datadir: Path, pair: str) -> Path:
-        pair_s = pair.replace("/", "_")
+        pair_s = misc.pair_to_filename(pair)
         filename = datadir.joinpath(f'{pair_s}-trades.{cls._get_file_extension()}')
         return filename