Update the get_notification_by_id to return a sensible message if the id is not a valid UUID.

Previously "Result not found" would be returned when the id is not a valid uuid, which does not make sense.
Now the message says "notification_id is not a valid UUID", this should be a clearer message for the client service.

app/v2/notifications/get_notifications.py

@@ -1,23 +1,17 @@
-import uuid
-
 from flask import jsonify, request, url_for, current_app
-from werkzeug.exceptions import abort
-
 from app import api_user, authenticated_service
 from app.dao import notifications_dao
 from app.schema_validation import validate
 from app.v2.notifications import v2_notification_blueprint
-from app.v2.notifications.notification_schemas import get_notifications_request
+from app.v2.notifications.notification_schemas import get_notifications_request, notification_by_id
 
 
-@v2_notification_blueprint.route("/<id>", methods=['GET'])
-def get_notification_by_id(id):
-    try:
-        casted_id = uuid.UUID(id)
-    except (ValueError, AttributeError):
-        abort(404)
+@v2_notification_blueprint.route("/<notification_id>", methods=['GET'])
+def get_notification_by_id(notification_id):
+    _data = {"notification_id": notification_id}
+    validate(_data, notification_by_id)
     notification = notifications_dao.get_notification_with_personalisation(
-        authenticated_service.id, casted_id, key_type=None
+        authenticated_service.id, notification_id, key_type=None
     )
 
     return jsonify(notification.serialize()), 200

app/v2/notifications/notification_schemas.py

@@ -20,6 +20,18 @@ template = {
     "required": ["id", "version", "uri"]
 }
 
+notification_by_id = {
+    "$schema": "http://json-schema.org/draft-04/schema#",
+    "description": "GET notification response schema",
+    "type": "object",
+    "title": "response v2/notification",
+    "properties": {
+        "notification_id": uuid
+    },
+    "required": ["notification_id"]
+}
+
+
 get_notification_response = {
     "$schema": "http://json-schema.org/draft-04/schema#",
     "description": "GET notification response schema",

tests/app/v2/notifications/test_get_notifications.py

@@ -210,15 +210,15 @@ def test_get_notification_by_id_invalid_id(client, sample_notification, id):
         path='/v2/notifications/{}'.format(id),
         headers=[('Content-Type', 'application/json'), auth_header])
 
-    assert response.status_code == 404
+    assert response.status_code == 400
     assert response.headers['Content-type'] == 'application/json'
 
     json_response = json.loads(response.get_data(as_text=True))
-    assert json_response == {
-        "message": "The requested URL was not found on the server.  "
-                   "If you entered the URL manually please check your spelling and try again.",
-        "result": "error"
-    }
+    assert json_response == {"errors": [
+        {"error": "ValidationError",
+         "message": "notification_id is not a valid UUID"
+         }],
+        "status_code": 400}
 
 
 @pytest.mark.parametrize('created_at_month, estimated_delivery', [
@@ -628,7 +628,7 @@ def test_get_notifications_renames_letter_statuses(client, sample_letter_templat
     )
     auth_header = create_authorization_header(service_id=letter_noti.service_id)
     response = client.get(
-        path=url_for('v2_notifications.get_notification_by_id', id=letter_noti.id),
+        path=url_for('v2_notifications.get_notification_by_id', notification_id=letter_noti.id),
         headers=[('Content-Type', 'application/json'), auth_header]
     )