Allow admin to assign shared runner to project through API

lib/api/runners.rb

@@ -203,11 +203,11 @@ module API
       end
 
       def authenticate_enable_runner!(runner)
-        forbidden!("Runner is shared") if runner.is_shared?
-        forbidden!("Runner is locked") if runner.locked?
         forbidden!("Runner is a group runner") if runner.group_type?
+
         return if current_user.admin?
 
+        forbidden!("Runner is locked") if runner.locked?
         forbidden!("No access granted") unless can?(current_user, :assign_runner, runner)
       end
 

spec/requests/api/runners_spec.rb

@@ -592,6 +592,15 @@ describe API::Runners do
           end.to change { project.runners.count }.by(+1)
           expect(response).to have_gitlab_http_status(201)
         end
+
+        it 'enables a shared runner' do
+          expect do
+            post api("/projects/#{project.id}/runners", admin), runner_id: shared_runner.id
+          end.to change { project.runners.count }.by(1)
+
+          expect(shared_runner.reload).not_to be_shared
+          expect(response).to have_gitlab_http_status(201)
+        end
       end
 
       context 'user is not admin' do