Fix/caching (#679)

* unlink file for JSONDecodeError

* fix for avoiding caching empty dicts

* fix for checking null dicts

1 files changed, 17 insertions, 6 deletions

diff --git a/wqflask/wqflask/correlation/pre_computes.py b/wqflask/wqflask/correlation/pre_computes.py
index 975a53b8..cb2f4470 100644
--- a/wqflask/wqflask/correlation/pre_computes.py
+++ b/wqflask/wqflask/correlation/pre_computes.py
@@ -6,29 +6,40 @@ from pathlib import Path
 from base.data_set import query_table_timestamp
 from base.webqtlConfig import TMPDIR
 
+from json.decoder import JSONDecodeError
+
 
 def fetch_all_cached_metadata(dataset_name):
     """in a gvein dataset fetch all the traits metadata"""
     file_name = generate_filename(dataset_name, suffix="metadata")
 
-    file_path = os.path.join(TMPDIR, file_name)
+    file_path = Path(TMPDIR, file_name)
 
     try:
         with open(file_path, "r+") as file_handler:
             dataset_metadata = json.load(file_handler)
+
             return (file_path, dataset_metadata)
 
     except FileNotFoundError:
-        Path(file_path).touch(exist_ok=True)
-        return (file_path, {})
+        pass
+
+    except JSONDecodeError:
+        file_path.unlink()
+
+    file_path.touch(exist_ok=True)
+
+    return (file_path, {})
 
 
 def cache_new_traits_metadata(dataset_metadata: dict, new_traits_metadata, file_path: str):
     """function to cache the new traits metadata"""
 
-    if bool(new_traits_metadata):
-        dataset_metadata.update(new_traits_metadata)
-             
+    if (dataset_metadata == {} and new_traits_metadata == {}):
+        return
+
+    dataset_metadata.update(new_traits_metadata)
+
     with open(file_path, "w+") as file_handler:
         json.dump(dataset_metadata, file_handler)