[API] Fix creating issue when assignee_id is empty

see https://gitlab.com/gitlab-org/gitlab-ce/issues/42025

1 files changed, 9 insertions, 0 deletions

diff --git a/spec/requests/api/issues_spec.rb b/spec/requests/api/issues_spec.rb
index 320217f2032..43218755f4f 100644
--- a/spec/requests/api/issues_spec.rb
+++ b/spec/requests/api/issues_spec.rb
@@ -847,6 +847,15 @@ describe API::Issues, :mailer do
         expect(json_response['assignee']['name']).to eq(user2.name)
         expect(json_response['assignees'].first['name']).to eq(user2.name)
       end
+
+      it 'creates a new project issue when assignee_id is empty' do
+        post api("/projects/#{project.id}/issues", user),
+          title: 'new issue', assignee_id: ''
+
+        expect(response).to have_gitlab_http_status(201)
+        expect(json_response['title']).to eq('new issue')
+        expect(json_response['assignee']).to be_nil
+      end
     end
 
     context 'single assignee restrictions' do