require fields in marshmallow schema to try and make it as hard

to break backwards compatability as possible

app/schemas.py

@@ -294,6 +294,20 @@ class NotificationWithTemplateSchema(BaseSchema):
 
 
 class NotificationWithPersonalisationSchema(NotificationWithTemplateSchema):
+    class Meta(NotificationWithTemplateSchema.Meta):
+        # mark as many fields as possible as required since this is a public api.
+        # WARNING: Does _not_ reference fields computed in handle_template_merge, such as
+        # 'body', 'subject' [for emails], and 'content_char_count'
+        fields = (
+            # db rows
+            'id', 'to', 'job_row_number', 'template_version', 'billable_units', 'notification_type', 'created_at',
+            'sent_at', 'sent_by', 'updated_at', 'status', 'reference',
+            # computed fields
+            'personalisation',
+            # relationships
+            'service', 'job', 'api_key', 'template'
+        )
+
     @pre_dump
     def handle_personalisation_property(self, in_data):
         self.personalisation = in_data.personalisation
@@ -533,7 +547,6 @@ job_email_template_notification_schema = JobEmailTemplateNotificationSchema()
 notification_schema = NotificationModelSchema()
 notification_with_template_schema = NotificationWithTemplateSchema()
 notification_with_personalisation_schema = NotificationWithPersonalisationSchema()
-notification_with_personalisation_schema_load_json = NotificationWithPersonalisationSchema(load_json=True)
 invited_user_schema = InvitedUserSchema()
 permission_schema = PermissionSchema()
 email_data_request_schema = EmailDataSchema()