Accounted for Topic.References on Delete()

JeremyCaney · JeremyCaney · commit f77cf59fd3a8 · 2021-02-06T16:26:25.000-08:00
Previously, the `TopicRepository`'s base `Delete()` class accounted for `Topic.Relationships` by removing any outgoing or incoming relationships that would be affected by the operation, thus ensuring that no orphaned topic references were persisted in memory from other parts of the topic graph. This helps ensure there aren't any legacy references maintained in the cache after a delete.

While this accounted for `Topic.Relationships`, however, it didn't account for the new `Topic.References`. This is corrected in this update.
diff --git a/OnTopic/Repositories/TopicRepository.cs b/OnTopic/Repositories/TopicRepository.cs
@@ -599,14 +599,30 @@ public override sealed void Delete([ValidatedNotNull]Topic topic, bool isRecursi
         }
       }
 
+      /*------------------------------------------------------------------------------------------------------------------------
+      | Remove references
+      \-----------------------------------------------------------------------------------------------------------------------*/
+      foreach (var descendantTopic in descendantTopics) {
+        foreach (var reference in descendantTopic.References) {
+          if (reference.Value is not null && !descendantTopics.Contains(reference.Value)) {
+            descendantTopic.References.Remove(reference.Key);
+          }
+        }
+      }
+
       /*------------------------------------------------------------------------------------------------------------------------
       | Remove incoming relationships
       \-----------------------------------------------------------------------------------------------------------------------*/
       foreach (var descendantTopic in descendantTopics) {
         foreach (var relationship in descendantTopic.IncomingRelationships) {
           foreach (var relatedTopic in relationship.Values.ToList()) {
             if (!descendantTopics.Contains(relatedTopic)) {
-              relatedTopic.Relationships.RemoveTopic(relationship.Key, descendantTopic);
+              if (relatedTopic.Relationships.Contains(relationship.Key, descendantTopic)) {
+                relatedTopic.Relationships.RemoveTopic(relationship.Key, descendantTopic);
+              }
+              else if (relatedTopic.References.Contains(relationship.Key)) {
+                relatedTopic.References.Remove(relationship.Key);
+              }
             }
           }
         }
