Test fallback on invalid metadata fields

mkdocs_blogging_plugin/plugin.py

@@ -353,5 +353,6 @@ def _parse_time(self, value):
             return value.timestamp()
         if isinstance(value, date):
             return datetime.combine(value, datetime.min.time()).timestamp()
-        if self.meta_time_format:
+        if self.meta_time_format and isinstance(value, str):
             return datetime.strptime(value, self.meta_time_format).timestamp()
+        return None

tests/test_format.py

@@ -50,3 +50,18 @@ def test_datetime_object(self):
         page = self.plugin.with_timestamp(page, False)
 
         assert page.meta["localized-time"] == "2023/04/12 09:15:30"
+
+    def test_datetime_object_fallback(self):
+        """
+        If meta.time is present but is an invalid type, we want to fall
+        back to using meta.date if available and valid.
+        """
+        page = SimpleNamespace(
+            meta={
+                "time": 500,
+                "date": datetime.datetime(2023, 4, 12, 9, 15, 30),
+            }
+        )
+        page = self.plugin.with_timestamp(page, False)
+
+        assert page.meta["localized-time"] == "2023/04/12 09:15:30"