Enforce service permissions

This should catch typos more quickly and obviously.

app/models/service.py

@@ -58,6 +58,16 @@ class Service(JSONModel):
         'letter',
     )
 
+    ALL_PERMISSIONS = TEMPLATE_TYPES + (
+        'edit_folder_permissions',
+        'email_auth',
+        'inbound_sms',
+        'international_letters',
+        'international_sms',
+        'upload_document',
+        'upload_letters',
+    )
+
     def __init__(self, _dict):
 
         super().__init__(_dict)
@@ -106,6 +116,8 @@ class Service(JSONModel):
         return not self.trial_mode
 
     def has_permission(self, permission):
+        if permission not in self.ALL_PERMISSIONS:
+            raise KeyError(f'{permission} is not a service permission')
         return permission in self.permissions
 
     def get_page_of_jobs(self, page):

tests/app/models/test_service.py

@@ -1,5 +1,7 @@
 import uuid
 
+import pytest
+
 from app.models.organisation import Organisation
 from app.models.service import Service
 from app.models.user import User
@@ -247,3 +249,9 @@ def test_service_without_organisation_doesnt_need_org_api(mocker, service_one):
 
     assert mock_redis_get.called is False
     assert mock_get_organisation.called is False
+
+
+def test_bad_permission_raises(service_one):
+    with pytest.raises(KeyError) as e:
+        Service(service_one).has_permission('foo')
+    assert str(e.value) == "'foo is not a service permission'"