1 files changed, 66 insertions, 0 deletions
diff --git a/spec/requests/search_controller_spec.rb b/spec/requests/search_controller_spec.rb
new file mode 100644
index 00000000000..52bfc480313
--- /dev/null
+++ b/spec/requests/search_controller_spec.rb
@@ -0,0 +1,66 @@
+# frozen_string_literal: true
+
+require 'spec_helper'
+
+RSpec.describe SearchController, type: :request do
+  let_it_be(:user) { create(:user) }
+  let_it_be(:group) { create(:group) }
+  let_it_be(:project) { create(:project, :public, :repository, :wiki_repo, name: 'awesome project', group: group) }
+
+  before_all do
+    login_as(user)
+  end
+
+  def send_search_request(params)
+    get search_path, params: params
+  end
+
+  shared_examples 'an efficient database result' do
+    it 'avoids N+1 database queries' do
+      create(object, *creation_traits, creation_args)
+
+      control = ActiveRecord::QueryRecorder.new(skip_cached: false) { send_search_request(params) }
+      create_list(object, 3, *creation_traits, creation_args)
+
+      expect { send_search_request(params) }.not_to exceed_all_query_limit(control).with_threshold(threshold)
+    end
+  end
+
+  describe 'GET /search' do
+    let(:creation_traits) { [] }
+
+    context 'for issues scope' do
+      let(:object) { :issue }
+      let(:creation_args) { { project: project } }
+      let(:params) { { search: '*', scope: 'issues' } }
+      let(:threshold) { 0 }
+
+      it_behaves_like 'an efficient database result'
+    end
+
+    context 'for merge_request scope' do
+      let(:creation_traits) { [:unique_branches] }
+      let(:object) { :merge_request }
+      let(:creation_args) { { source_project: project } }
+      let(:params) { { search: '*', scope: 'merge_requests' } }
+      let(:threshold) { 0 }
+
+      it_behaves_like 'an efficient database result'
+    end
+
+    context 'for project scope' do
+      let(:creation_traits) { [:public] }
+      let(:object) { :project }
+      let(:creation_args) { {} }
+      let(:params) { { search: '*', scope: 'projects' } }
+      # some N+1 queries still exist
+      # each project requires 3 extra queries
+      #   - one count for forks
+      #   - one count for open MRs
+      #   - one count for open Issues
+      let(:threshold) { 9 }
+
+      it_behaves_like 'an efficient database result'
+    end
+  end
+end