Update _id deletion comments to clarify cache update trigger

osf/models/preprint.py

@@ -313,7 +313,7 @@ def create(cls, provider, title, creator, description):
         )
         versioned_guid.save()
 
-        del preprint._id
+        del preprint._id  # trigger _id cache update
 
         return preprint
 
@@ -426,7 +426,7 @@ def create_version(cls, create_from_guid, auth):
         )
         guid_version.save()
 
-        del preprint._id
+        del preprint._id  # trigger _id cache update
 
         # Add contributors
         for contributor_info in latest_version.contributor_set.exclude(user=latest_version.creator).values('visible', 'user_id', '_order'):
@@ -442,7 +442,7 @@ def create_version(cls, create_from_guid, auth):
             guid_obj.object_id = preprint.pk
             guid_obj.content_type = ContentType.objects.get_for_model(preprint)
             guid_obj.save()
-            del preprint._id
+            del preprint._id  # trigger _id cache update
 
         return preprint, data_to_update
 

osf_tests/management_commands/test_check_crossref_dois.py

@@ -32,7 +32,7 @@ def stuck_preprint(self):
         guid._id = 'guid0'
         guid.save()
 
-        del preprint._id
+        del preprint._id  # trigger _id cache update
         preprint.save()
         return preprint
 

osf_tests/test_guid.py

@@ -565,6 +565,6 @@ def test_versioned_preprint_id_property(self, creator, preprint_provider):
         assert preprint._id == expected_guid
 
         GuidVersionsThrough.objects.filter(guid=preprint_guid).delete()
-        del preprint._id
+        del preprint._id  # trigger _id cache update
 
         assert preprint._id is None