New endpoint to fetch a single reply-to email address by id

tests/app/dao/test_service_email_reply_to_dao.py

@@ -1,9 +1,12 @@
+import uuid
+
 import pytest
+from sqlalchemy.exc import SQLAlchemyError
 
 from app.dao.service_email_reply_to_dao import (
     create_or_update_email_reply_to,
     dao_get_reply_to_by_service_id,
-    add_reply_to_email_address_for_service, update_reply_to_email_address)
+    add_reply_to_email_address_for_service, update_reply_to_email_address, dao_get_reply_to_by_id)
 from app.errors import InvalidRequest
 from app.models import ServiceEmailReplyTo
 from tests.app.db import create_reply_to_email, create_service
@@ -191,3 +194,20 @@ def test_update_reply_to_email_address_raises_exception_if_single_reply_to_and_s
                                       reply_to_id=first_reply_to.id,
                                       email_address='should@fail.com',
                                       is_default=False)
+
+
+def test_dao_get_reply_to_by_id(sample_service):
+    reply_to = create_reply_to_email(service=sample_service, email_address='email@address.com')
+    result = dao_get_reply_to_by_id(service_id=sample_service.id, reply_to_id=reply_to.id)
+    assert result == reply_to
+
+
+def test_dao_get_reply_to_by_id_raises_sqlalchemy_error_when_reply_to_does_not_exist(sample_service):
+    with pytest.raises(SQLAlchemyError):
+        dao_get_reply_to_by_id(service_id=sample_service.id, reply_to_id=uuid.uuid4())
+
+
+def test_dao_get_reply_to_by_id_raises_sqlalchemy_error_when_service_does_not_exist(sample_service):
+    reply_to = create_reply_to_email(service=sample_service, email_address='email@address.com')
+    with pytest.raises(SQLAlchemyError):
+        dao_get_reply_to_by_id(service_id=uuid.uuid4(), reply_to_id=reply_to.id)

tests/app/service/test_rest.py

@@ -2290,3 +2290,14 @@ def test_update_service_reply_to_email_address_404s_when_invalid_service_id(clie
     result = json.loads(response.get_data(as_text=True))
     assert result['result'] == 'error'
     assert result['message'] == 'No result found'
+
+
+def test_get_email_reply_to_address(client, notify_db, notify_db_session):
+    service = create_service(notify_db=notify_db, notify_db_session=notify_db_session)
+    reply_to = create_reply_to_email(service, 'test_a@mail.com')
+
+    response = client.get('/service/{}/email-reply-to/{}'.format(service.id, reply_to.id),
+                          headers=[('Content-Type', 'application/json'), create_authorization_header()])
+
+    assert response.status_code == 200
+    assert json.loads(response.get_data(as_text=True)) == reply_to.serialize()