Optimize SQL queries used in Groups::GroupMembersController#create27374-groups-groupmemberscontroller-create-is-slow-due-to-sql

The following optimizations were performed:

- Add new association to GroupMember and ProjectMember

  This new association will allow us to check if a user is a member of a
  Project or Group through a single query instead of two.

- Optimize retrieving of Members when adding multiple Users

1 files changed, 27 insertions, 0 deletions

diff --git a/spec/support/group_members_shared_example.rb b/spec/support/group_members_shared_example.rb
new file mode 100644
index 00000000000..547c83c7955
--- /dev/null
+++ b/spec/support/group_members_shared_example.rb
@@ -0,0 +1,27 @@
+RSpec.shared_examples 'members and requesters associations' do
+  describe '#members_and_requesters' do
+    it 'includes members and requesters' do
+      member_and_requester_user_ids = namespace.members_and_requesters.pluck(:user_id)
+
+      expect(member_and_requester_user_ids).to include(requester.id, developer.id)
+    end
+  end
+
+  describe '#members' do
+    it 'includes members and exclude requesters' do
+      member_user_ids = namespace.members.pluck(:user_id)
+
+      expect(member_user_ids).to include(developer.id)
+      expect(member_user_ids).not_to include(requester.id)
+    end
+  end
+
+  describe '#requesters' do
+    it 'does not include requesters' do
+      requester_user_ids = namespace.requesters.pluck(:user_id)
+
+      expect(requester_user_ids).to include(requester.id)
+      expect(requester_user_ids).not_to include(developer.id)
+    end
+  end
+end