Replaced first queries with one queries, which throws a NoResultFound.

Able to remove many of the None checks as a result of this.
Fixed the tests were needed.

tests/app/dao/test_invited_user_dao.py

@@ -1,5 +1,9 @@
 from datetime import datetime, timedelta
 import uuid
+
+import pytest
+from sqlalchemy.orm.exc import NoResultFound
+
 from app import db
 
 from app.models import InvitedUser
@@ -50,8 +54,9 @@ def test_get_invited_user_by_id(notify_db, notify_db_session, sample_invited_use
 def test_get_unknown_invited_user_returns_none(notify_db, notify_db_session, sample_service):
     unknown_id = uuid.uuid4()
 
-    unknown = get_invited_user(sample_service.id, unknown_id)
-    assert unknown is None
+    with pytest.raises(NoResultFound) as e:
+        get_invited_user(sample_service.id, unknown_id)
+    assert 'No row was found for one()' in str(e.value)
 
 
 def test_get_invited_users_for_service(notify_db, notify_db_session, sample_service):

tests/app/dao/test_services_dao.py

@@ -171,4 +171,6 @@ def test_cannot_get_service_by_id_and_owned_by_different_user(service_factory, s
     save_model_user(new_user)
     service2 = service_factory.get('service 2', new_user)
     assert dao_fetch_service_by_id_and_user(service1.id, sample_user.id).name == 'service 1'
-    assert not dao_fetch_service_by_id_and_user(service2.id, sample_user.id)
+    with pytest.raises(NoResultFound) as e:
+        dao_fetch_service_by_id_and_user(service2.id, sample_user.id)
+    assert 'No row was found for one()' in str(e)

tests/app/invite/test_invite_rest.py

@@ -233,8 +233,7 @@ def test_update_invited_user_for_wrong_service_returns_404(notify_api, sample_in
                                    headers=[('Content-Type', 'application/json'), auth_header])
             assert response.status_code == 404
             json_response = json.loads(response.get_data(as_text=True))['message']
-            assert json_response == 'Invited user not found for service id: {} and invited user id: {}'\
-                .format(bad_service_id, sample_invited_user.id)
+            assert json_response == 'No result found'
 
 
 def test_update_invited_user_for_invalid_data_returns_400(notify_api, sample_invited_user):

tests/app/service/test_rest.py

@@ -166,8 +166,7 @@ def test_get_service_by_id_should_404_if_no_service_for_user(notify_api, sample_
             assert resp.status_code == 404
             json_resp = json.loads(resp.get_data(as_text=True))
             assert json_resp['result'] == 'error'
-            assert json_resp['message'] == \
-                'Service not found for service id: {0} and for user id: {1}'.format(service_id, sample_user.id)
+            assert json_resp['message'] == 'No result found'
 
 
 def test_create_service(notify_api, sample_user):
@@ -257,9 +256,9 @@ def test_should_not_create_service_with_missing_if_user_id_is_not_in_database(no
                 data=json.dumps(data),
                 headers=headers)
             json_resp = json.loads(resp.get_data(as_text=True))
-            assert resp.status_code == 400
+            assert resp.status_code == 404
             assert json_resp['result'] == 'error'
-            assert 'not found' in json_resp['message']['user_id']
+            assert 'No result found' == json_resp['message']
 
 
 def test_should_not_create_service_if_missing_data(notify_api, sample_user):