fix(github) Fix 404s not being handled in repository search (#14030)

fix(github) Fix 422s not being handled in repository search

Fixes SENTRY-95M

Author: markstory

src/sentry/integrations/github/search.py

@@ -52,6 +52,10 @@ def get(self, request, organization, integration_id):
             except ApiError as err:
                 if err.code == 403:
                     return Response({'detail': 'Rate limit exceeded'}, status=429)
+                if err.code == 422:
+                    return Response({
+                        'detail': 'Repositories could not be searched because they do not exist, or you do not have access to them.'
+                    }, status=404)
                 raise
             return Response([{
                 'label': i['name'],

tests/sentry/integrations/github/test_search.py

@@ -143,6 +143,30 @@ def test_finds_repo_results(self):
             {'value': 'test/exhaust', 'label': 'exhaust'}
         ]
 
+    @responses.activate
+    def test_repo_search_validation_error(self):
+        responses.add(
+            responses.GET,
+            self.base_url + '/search/repositories?q=org:test%20nope',
+            json={
+                'message': 'Validation Error',
+                'errors': [
+                    {'message': 'Cannot search for that org'}
+                ]
+            },
+            status=422
+        )
+        resp = self.client.get(
+            self.url,
+            data={
+                'field': 'repo',
+                'query': 'nope',
+                'repo': 'example',
+            }
+        )
+        assert resp.status_code == 404
+        assert 'detail' in resp.data
+
     @responses.activate
     def test_finds_no_external_issues_results(self):
         responses.add(