Remove N+1 queries from users autocomplete

Both of these were related to groups:

1. We need to preload routes (using the `with_route` scope) if we're
   going to get the group's path.
2. We were counting each group's members separately.

They're in the same commit because the spec for N+1 detection wouldn't
pass with only one of these fixes.

1 files changed, 40 insertions, 13 deletions

diff --git a/spec/services/projects/participants_service_spec.rb b/spec/services/projects/participants_service_spec.rb
index 6040f9100f8..4b6d0c51363 100644
--- a/spec/services/projects/participants_service_spec.rb
+++ b/spec/services/projects/participants_service_spec.rb
@@ -2,29 +2,56 @@ require 'spec_helper'
 
 describe Projects::ParticipantsService do
   describe '#groups' do
+    set(:user) { create(:user) }
+    set(:project) { create(:project, :public) }
+    let(:service) { described_class.new(project, user) }
+
+    it 'avoids N+1 queries' do
+      group_1 = create(:group)
+      group_1.add_owner(user)
+
+      service.groups # Run general application warmup queries
+      control_count = ActiveRecord::QueryRecorder.new { service.groups }.count
+
+      group_2 = create(:group)
+      group_2.add_owner(user)
+
+      expect { service.groups }.not_to exceed_query_limit(control_count)
+    end
+
+    it 'returns correct user counts for groups' do
+      group_1 = create(:group)
+      group_1.add_owner(user)
+      group_1.add_owner(create(:user))
+
+      group_2 = create(:group)
+      group_2.add_owner(user)
+      create(:group_member, :access_request, group: group_2, user: create(:user))
+
+      expect(service.groups).to contain_exactly(
+        a_hash_including(name: group_1.full_name, count: 2),
+        a_hash_including(name: group_2.full_name, count: 1)
+      )
+    end
+
     describe 'avatar_url' do
-      let(:project) { create(:project, :public) }
       let(:group) { create(:group, avatar: fixture_file_upload('spec/fixtures/dk.png')) }
-      let(:user) { create(:user) }
-      let!(:group_member) { create(:group_member, group: group, user: user) }
 
-      it 'should return an url for the avatar' do
-        participants = described_class.new(project, user)
-        groups = participants.groups
+      before do
+        group.add_owner(user)
+      end
 
-        expect(groups.size).to eq 1
-        expect(groups.first[:avatar_url]).to eq("/uploads/-/system/group/avatar/#{group.id}/dk.png")
+      it 'should return an url for the avatar' do
+        expect(service.groups.size).to eq 1
+        expect(service.groups.first[:avatar_url]).to eq("/uploads/-/system/group/avatar/#{group.id}/dk.png")
       end
 
       it 'should return an url for the avatar with relative url' do
         stub_config_setting(relative_url_root: '/gitlab')
         stub_config_setting(url: Settings.send(:build_gitlab_url))
 
-        participants = described_class.new(project, user)
-        groups = participants.groups
-
-        expect(groups.size).to eq 1
-        expect(groups.first[:avatar_url]).to eq("/gitlab/uploads/-/system/group/avatar/#{group.id}/dk.png")
+        expect(service.groups.size).to eq 1
+        expect(service.groups.first[:avatar_url]).to eq("/gitlab/uploads/-/system/group/avatar/#{group.id}/dk.png")
       end
     end
   end