1 files changed, 37 insertions, 0 deletions
diff --git a/spec/services/groups/participants_service_spec.rb b/spec/services/groups/participants_service_spec.rb
new file mode 100644
index 00000000000..750aead277f
--- /dev/null
+++ b/spec/services/groups/participants_service_spec.rb
@@ -0,0 +1,37 @@
+# frozen_string_literal: true
+
+require 'spec_helper'
+
+RSpec.describe Groups::ParticipantsService do
+  describe '#group_members' do
+    let(:user) { create(:user) }
+    let(:parent_group) { create(:group) }
+    let(:group) { create(:group, parent: parent_group) }
+    let(:subgroup) { create(:group, parent: group) }
+    let(:subproject) { create(:project, group: subgroup) }
+
+    it 'returns all members in parent groups, sub-groups, and sub-projects' do
+      parent_group.add_developer(create(:user))
+      subgroup.add_developer(create(:user))
+      subproject.add_developer(create(:user))
+
+      result = described_class.new(group, user).execute(nil)
+
+      expected_users = (group.self_and_hierarchy.flat_map(&:users) + subproject.users)
+        .map { |user| user_to_autocompletable(user) }
+
+      expect(expected_users.count).to eq(3)
+      expect(result).to include(*expected_users)
+    end
+  end
+
+  def user_to_autocompletable(user)
+    {
+      type: user.class.name,
+      username: user.username,
+      name: user.name,
+      avatar_url: user.avatar_url,
+      availability: user&.status&.availability
+    }
+  end
+end