Improve management of cache loading errors (#62)

plex_auto_languages/plex_server_cache.py

@@ -107,11 +107,17 @@ def _get_cache_file_path(self):
         return os.path.join(cache_dir, self._plex.unique_id)
 
     def _load(self):
-        if not os.path.exists(self._cache_file_path):
+        if not os.path.exists(self._cache_file_path) or not os.path.isfile(self._cache_file_path):
             return False
         logger.debug("[Cache] Loading server cache from file")
-        with open(self._cache_file_path, "r", encoding="utf-8") as stream:
-            cache = json.load(stream)
+        try:
+            with open(self._cache_file_path, "r", encoding="utf-8") as stream:
+                cache = json.load(stream)
+        except json.JSONDecodeError:
+            logger.warning("[Cache] The cache is corrupted, clearing the cache before trying again")
+            if os.path.exists(self._cache_file_path) and os.path.isfile(self._cache_file_path):
+                os.remove(self._cache_file_path)
+            return False
         self.newly_updated = cache.get("newly_updated", self.newly_updated)
         self.newly_updated = {key: isoparse(value) for key, value in self.newly_updated.items()}
         self.newly_added = cache.get("newly_added", self.newly_added)

tests/conftest.py

@@ -2,10 +2,13 @@
 import pytest
 import plexapi
 
+from plex_auto_languages.utils.logger import init_logger
 from plex_auto_languages.plex_server import PlexServer
 from plex_auto_languages.utils.configuration import Configuration
 
 
+init_logger()
+
 SERVER_BASEURL = plexapi.CONFIG.get("auth.server_baseurl")
 SERVER_TOKEN = plexapi.CONFIG.get("auth.server_token")
 

tests/test_plex_server_cache.py

@@ -56,6 +56,14 @@ def test_load_save():
 
             assert old_episode_parts == cache.episode_parts
 
+            with open(mocked_path, "w") as stream:
+                stream.write("Not a JSON object")
+            assert os.path.exists(mocked_path)
+            mocked_refresh.reset_mock()
+            cache = PlexServerCache(None)
+            mocked_refresh.assert_called_once()
+            assert not os.path.exists(mocked_path)
+
 
 def test_instance_users(plex):
     assert plex.cache.get_instance_users() is None