add relationship

enrollments-events/app/enrollment.py

@@ -73,15 +73,34 @@ def enroll(
             }
         )
 
-        for entity in linked_entities:
-            keyprefix = entity.type.lower()
+        # Relationships between this enrollment and its related entities
+        for parent_entity in linked_entities:
+            perent_id = parent_entity.id
+            entity_sk = f'LINKED_ENTITIES#{parent_entity.type}'
+            keyprefix = parent_entity.type.lower()
+
+            # Child knows the parent
             transact.put(
                 item={
                     'id': enrollment.id,
-                    'sk': f'LINKED_ENTITIES#{entity.type}',
+                    'sk': entity_sk,
+                    'kind': 'PARENT',
                     'created_at': now_,
-                    f'{keyprefix}_id': entity.id,
-                }
+                    f'{keyprefix}_id': perent_id,
+                },
+                cond_expr='attribute_not_exists(sk)',
+            )
+
+            # Parent knows the child
+            transact.put(
+                item={
+                    'id': perent_id,
+                    'sk': entity_sk,
+                    'kind': 'CHILD',
+                    'created_at': now_,
+                    f'{keyprefix}_id': enrollment.id,
+                },
+                cond_expr='attribute_not_exists(sk)',
             )
 
         if org:

enrollments-events/template.yaml

@@ -222,7 +222,7 @@ Resources:
   EventSendReminderEmailsFunction:
     Type: AWS::Serverless::Function
     Properties:
-      Handler: events.emails.send_reminder_emails.lambda_handler
+      Handler: events.send_reminder_emails.lambda_handler
       LoggingConfig:
         LogGroup: !Ref EventLog
       Policies:

enrollments-events/tests/events/test_reenroll_if_failed.py

@@ -1,6 +1,6 @@
 import app.events.reenroll_if_failed as app
 from aws_lambda_powertools.utilities.typing import LambdaContext
-from layercake.dynamodb import DynamoDBPersistenceLayer
+from layercake.dynamodb import DynamoDBPersistenceLayer, KeyPair
 
 
 def test_reenroll(
@@ -27,3 +27,21 @@ def test_reenroll(
         }
     }
     assert app.lambda_handler(event, lambda_context)  # type: ignore
+
+    parent_entity = dynamodb_persistence_layer.collection.get_item(
+        KeyPair(
+            pk='294e9864-8284-4287-b153-927b15d90900',
+            sk='LINKED_ENTITIES#ENROLLMENT',
+        )
+    )
+    assert parent_entity['kind'] == 'CHILD'
+
+    child_entity = dynamodb_persistence_layer.collection.get_item(
+        KeyPair(
+            pk=parent_entity['enrollment_id'],
+            sk='LINKED_ENTITIES#ENROLLMENT',
+        )
+    )
+
+    assert child_entity['enrollment_id'] == parent_entity['id']
+    assert child_entity['kind'] == 'PARENT'