From d52ee4606a2e173dd8f6fc4341c91d238796a009 Mon Sep 17 00:00:00 2001
From: Chris Hill-Scott <me@quis.cc>
Date: Tue, 4 Sep 2018 12:59:53 +0100
Subject: [PATCH] Add error handler for duplicate domain

---
 app/email_branding/rest.py            | 19 ++++++++++++++++++-
 tests/app/email_branding/test_rest.py | 27 +++++++++++++++++++++++++++
 2 files changed, 45 insertions(+), 1 deletion(-)

diff --git a/app/email_branding/rest.py b/app/email_branding/rest.py
index 0991c9d0b..990f1905e 100644
--- a/app/email_branding/rest.py
+++ b/app/email_branding/rest.py
@@ -1,4 +1,5 @@
-from flask import Blueprint, jsonify, request
+from flask import Blueprint, current_app, jsonify, request
+from sqlalchemy.exc import IntegrityError
 
 from app.dao.email_branding_dao import (
     dao_create_email_branding,
@@ -18,6 +19,22 @@ email_branding_blueprint = Blueprint('email_branding', __name__)
 register_errors(email_branding_blueprint)
 
 
+@email_branding_blueprint.errorhandler(IntegrityError)
+def handle_integrity_error(exc):
+    """
+    Handle integrity errors caused by the unique constraint on domain
+    """
+    if 'domain' in str(exc):
+        return jsonify(
+            result='error',
+            message={'name': ["Duplicate domain '{}'".format(
+                exc.params.get('domain')
+            )]}
+        ), 400
+    current_app.logger.exception(exc)
+    return jsonify(result='error', message="Internal server error"), 500
+
+
 @email_branding_blueprint.route('', methods=['GET'])
 def get_email_branding_options():
     email_branding_options = [o.serialize() for o in dao_get_email_branding_options()]
diff --git a/tests/app/email_branding/test_rest.py b/tests/app/email_branding/test_rest.py
index 03311514a..7c7954887 100644
--- a/tests/app/email_branding/test_rest.py
+++ b/tests/app/email_branding/test_rest.py
@@ -257,3 +257,30 @@ def test_update_email_branding_reject_invalid_brand_type(admin_request, notify_d
     )
 
     assert response['errors'][0]['message'] == 'brand_type NOT A TYPE is not one of [org, both, org_banner]'
+
+
+def test_400_for_duplicate_domain(admin_request, notify_db_session):
+    branding_1 = create_email_branding()
+    branding_2 = create_email_branding()
+    admin_request.post(
+        'email_branding.update_email_branding',
+        _data={'domain': 'example.com'},
+        email_branding_id=branding_1.id,
+    )
+
+    response = admin_request.post(
+        'email_branding.update_email_branding',
+        _data={'domain': 'example.com'},
+        email_branding_id=branding_2.id,
+        _expected_status=400,
+    )
+    assert response['result'] == 'error'
+    assert response['message']['name'] == ["Duplicate domain 'example.com'"]
+
+    response = admin_request.post(
+        'email_branding.create_email_branding',
+        _data={'domain': 'example.com'},
+        _expected_status=400,
+    )
+    assert response['result'] == 'error'
+    assert response['message']['name'] == ["Duplicate domain 'example.com'"]