Quietly ignore extra personalisation

> If a user makes an API request with additional personalisation fields,
> we should simply discard any fields that the template doesn't have.
>
> This gives a couple of related advantages:
>
> - modifying template parameters no longer requires downtime for
>   clients - as they can pass in extra new parameters before a template
>   change, or continue passing in old unused parameters after removing
>   them from a template
>
> - services can pass in large user objects, for example, and then play
>   around with templates adding and removing fields at will
>
> we should make sure we still return an error if a user doesn't pass in
> a required parameter.

– https://www.pivotaltracker.com/story/show/140774195

app/notifications/process_notifications.py

@@ -23,11 +23,6 @@ def check_placeholders(template_object):
         message = 'Template missing personalisation: {}'.format(", ".join(template_object.missing_data))
         raise BadRequestError(fields=[{'template': message}], message=message)
 
-    if template_object.additional_data:
-        message = 'Template personalisation not needed for template: {}'.format(
-            ", ".join(template_object.additional_data))
-        raise BadRequestError(fields=[{'template': message}], message=message)
-
 
 def persist_notification(template_id,
                          template_version,

app/notifications/rest.py

@@ -300,11 +300,6 @@ def create_template_object_for_notification(template, personalisation):
         errors = {'template': [message]}
         raise InvalidRequest(errors, status_code=400)
 
-    if template_object.additional_data:
-        message = 'Personalisation not needed for template: {}'.format(", ".join(template_object.additional_data))
-        errors = {'template': [message]}
-        raise InvalidRequest(errors, status_code=400)
-
     if (
         template_object.template_type == SMS_TYPE and
         template_object.content_count > current_app.config.get('SMS_CHAR_COUNT_LIMIT')

app/template/rest.py

@@ -101,13 +101,6 @@ def preview_template_by_id_and_service_id(service_id, template_id):
             ]}, status_code=400
         )
 
-    if template_object.additional_data:
-        raise InvalidRequest(
-            {'template': [
-                'Personalisation not needed for template: {}'.format(", ".join(template_object.additional_data))
-            ]}, status_code=400
-        )
-
     data['subject'], data['content'] = template_object.subject, str(template_object)
 
     return jsonify(data)