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

tests/app/notifications/rest/test_send_notification.py

@@ -913,14 +913,12 @@ def test_create_template_raises_invalid_request_exception_with_missing_personali
     assert {'template': ['Missing personalisation:  Name']} == e.value.message
 
 
-def test_create_template_raises_invalid_request_exception_with_too_much_personalisation_data(
+def test_create_template_doesnt_raise_with_too_much_personalisation(
         sample_template_with_placeholders
 ):
     from app.notifications.rest import create_template_object_for_notification
     template = Template.query.get(sample_template_with_placeholders.id)
-    with pytest.raises(InvalidRequest) as e:
-        create_template_object_for_notification(template, {'name': 'Jo', 'extra': 'stuff'})
-        assert {'template': ['Personalisation not needed for template: foo']} in e.value.message
+    create_template_object_for_notification(template, {'name': 'Jo', 'extra': 'stuff'})
 
 
 @pytest.mark.parametrize(

tests/app/notifications/test_process_notification.py

@@ -36,11 +36,9 @@ def test_create_content_for_notification_fails_with_missing_personalisation(samp
         create_content_for_notification(template, None)
 
 
-def test_create_content_for_notification_fails_with_additional_personalisation(sample_template_with_placeholders):
+def test_create_content_for_notification_allows_additional_personalisation(sample_template_with_placeholders):
     template = Template.query.get(sample_template_with_placeholders.id)
-    with pytest.raises(BadRequestError) as e:
-        create_content_for_notification(template, {'name': 'Bobby', 'Additional placeholder': 'Data'})
-    assert e.value.message == 'Template personalisation not needed for template: Additional placeholder'
+    create_content_for_notification(template, {'name': 'Bobby', 'Additional placeholder': 'Data'})
 
 
 @freeze_time("2016-01-01 11:09:00.061258")

tests/app/template/test_rest.py

@@ -374,8 +374,9 @@ def test_should_get_a_single_template(
             'about your ((thing))',
             'hello ((name)) we’ve received your ((thing))',
             '/service/{}/template/{}/preview?name=Amala&thing=document&foo=bar',
-            None, None,
-            'Personalisation not needed for template: foo'
+            'about your document',
+            'hello Amala we’ve received your document',
+            None,
         )
     ]
 )