better error handling

backend/src/overpass/overpass.py

@@ -102,6 +102,7 @@ class Overpass :
             request = urllib.request.Request(self.overpass_url, data=data, headers=self.headers)
 
             with urllib.request.urlopen(request) as response:
+
                 # Convert the HTTPResponse to a string and load data
                 response_data = response.read().decode('utf-8')  
                 data = json.loads(response_data)
@@ -110,7 +111,6 @@ class Overpass :
                 elements = data.get('elements', [])
                 self.caching_strategy.set(cache_key, elements)
                 self.logger.debug(f'Cache set for {cache_key}')
-
         except urllib.error.URLError as e:
             raise ConnectionError(f"Error connecting to Overpass API: {e}") from e
         except Exception as exc :
@@ -333,7 +333,11 @@ def fill_cache():
 
                 # Read the whole file content as a string
                 with open(entry.path, 'r') as f:
-                    json_data = json.load(f)
+                    try :
+                        json_data = json.load(f)
+                    except Exception as exc :
+                        raise json.JSONDecodeError(f'Failed to parse file {f}') from exc
+        
 
                 # Fill the cache with the query and key
                 overpass.fill_cache(json_data)