refactor file_load_json to be standalone

freqtrade/data/history.py

@@ -67,18 +67,10 @@ def load_tickerdata_file(
     path = make_testdata_path(datadir)
     pair_s = pair.replace('/', '_')
     file = path.joinpath(f'{pair_s}-{ticker_interval}.json')
-    gzipfile = file.with_suffix(file.suffix + '.gz')
 
-    # Try gzip file first, otherwise regular json file.
-    if gzipfile.is_file():
-        logger.debug('Loading ticker data from file %s', gzipfile)
-        with gzip.open(gzipfile) as tickerdata:
-            pairdata = misc.json_load(tickerdata)
-    elif file.is_file():
-        logger.debug('Loading ticker data from file %s', file)
-        with open(file) as tickerdata:
-            pairdata = misc.json_load(tickerdata)
-    else:
+    pairdata = misc.file_load_json(file)
+
+    if not pairdata:
         return None
 
     if timerange:

freqtrade/misc.py

@@ -83,13 +83,31 @@ def file_dump_json(filename, data, is_zip=False) -> None:
             rapidjson.dump(data, fp, default=str, number_mode=rapidjson.NM_NATIVE)
 
 
-def json_load(data):
+def json_load(datafile):
     """
     load data with rapidjson
     Use this to have a consistent experience,
     sete number_mode to "NM_NATIVE" for greatest speed
     """
-    return rapidjson.load(data, number_mode=rapidjson.NM_NATIVE)
+    return rapidjson.load(datafile, number_mode=rapidjson.NM_NATIVE)
+
+
+def file_load_json(file):
+
+    gzipfile = file.with_suffix(file.suffix + '.gz')
+
+    # Try gzip file first, otherwise regular json file.
+    if gzipfile.is_file():
+        logger.debug('Loading ticker data from file %s', gzipfile)
+        with gzip.open(gzipfile) as tickerdata:
+            pairdata = json_load(tickerdata)
+    elif file.is_file():
+        logger.debug('Loading ticker data from file %s', file)
+        with open(file) as tickerdata:
+            pairdata = json_load(tickerdata)
+    else:
+        return None
+    return pairdata
 
 
 def format_ms_time(date: int) -> str:

freqtrade/tests/test_misc.py

@@ -2,11 +2,12 @@
 
 import datetime
 from unittest.mock import MagicMock
+from pathlib import Path
 
 from freqtrade.data.converter import parse_ticker_dataframe
 from freqtrade.misc import (common_datearray, datesarray_to_datetimearray,
-                            file_dump_json, format_ms_time, shorten_date)
-from freqtrade.data.history import load_tickerdata_file
+                            file_dump_json, file_load_json, format_ms_time, shorten_date)
+from freqtrade.data.history import load_tickerdata_file, make_testdata_path
 from freqtrade.strategy.default_strategy import DefaultStrategy
 
 
@@ -57,6 +58,19 @@ def test_file_dump_json(mocker) -> None:
     assert json_dump.call_count == 1
 
 
+def test_file_load_json(mocker) -> None:
+
+    # 7m .json does not exist
+    ret = file_load_json(make_testdata_path(None).joinpath('UNITTEST_BTC-7m.json'))
+    assert not ret
+    # 1m json exists (but no .gz exists)
+    ret = file_load_json(make_testdata_path(None).joinpath('UNITTEST_BTC-1m.json'))
+    assert ret
+    # 8 .json is empty and will fail if it's loaded. .json.gz is a copy of 1.json
+    ret = file_load_json(make_testdata_path(None).joinpath('UNITTEST_BTC-8m.json'))
+    assert ret
+
+
 def test_format_ms_time() -> None:
     # Date 2018-04-10 18:02:01
     date_in_epoch_ms = 1523383321000