almost there

src/ytdl_sub/entries/script/variable_definitions.py

@@ -448,7 +448,17 @@ class _Variables:
         )
 
     @property
-    def playlist_max_upload_year(self) -> MetadataVariable:
+    def playlist_max_upload_date(self) -> Variable:
+        """
+        Returns
+        -------
+            Max upload_date for all entries in this entry's playlist if it exists, otherwise returns
+            ``upload_date``
+        """
+        return Variable("playlist_max_upload_date")
+
+    @property
+    def playlist_max_upload_year(self) -> Variable:
         """
         Returns
         -------
@@ -457,9 +467,7 @@ class _Variables:
             ``upload_year``
         """
         # override in EntryParent
-        return MetadataVariable(
-            variable_name="playlist_max_upload_year", metadata_key="playlist_max_upload_year"
-        )
+        return Variable("playlist_max_upload_year")
 
     @property
     def playlist_max_upload_year_truncated(self) -> Variable:

src/ytdl_sub/entries/script/variable_scripts.py

@@ -248,11 +248,11 @@ SOURCE_DERIVED_VARIABLES: Dict[Variable, str] = {
 }
 
 SIBLING_VARIABLES: Dict[Variable, str] = {
-    v.playlist_max_upload_year: f"""{{
+    v.playlist_max_upload_date: f"""{{
         %array_reduce(
             %if_passthrough(
-                %extract_field_from_siblings('{v.upload_year.variable_name}'),
-                [{v.upload_year.variable_name}]
+                %extract_field_from_siblings('{v.upload_date.variable_name}'),
+                [{v.upload_date.variable_name}]
             ),
             %max
         )
@@ -260,7 +260,10 @@ SIBLING_VARIABLES: Dict[Variable, str] = {
 }
 
 SIBLING_DERIVED_VARIABLES: Dict[Variable, str] = {
-    v.playlist_max_upload_year_truncated: f"{{%int(%slice(%string({v.playlist_max_upload_year.variable_name}), 2))}}",
+    v.playlist_max_upload_year: date_metadata(v.playlist_max_upload_date, "year"),
+    v.playlist_max_upload_year_truncated: date_metadata(
+        v.playlist_max_upload_date, "year_truncated"
+    ),
 }
 
 _VARIABLE_SCRIPTS: Dict[Variable, str] = {}

tests/unit/entries/test_entry.py

@@ -7,11 +7,14 @@ from ytdl_sub.entries.script.variable_definitions import VARIABLES as v
 class TestEntry(object):
     def test_entry_to_dict(self, mock_entry, mock_entry_to_dict):
         out = mock_entry.to_dict()
+
+        # Delete non-legacy variables to reuse old to_dict comparision
         del out[v.entry_metadata.variable_name]
         del out[v.ytdl_sub_input_url.variable_name]
         del out[v.playlist_metadata.variable_name]
         del out[v.source_metadata.variable_name]
         del out[v.sibling_metadata.variable_name]
+        del out[v.playlist_max_upload_date.variable_name]
         assert out == mock_entry_to_dict
 
     def test_entry_missing_kwarg(self, mock_entry):