Add basic_search parameter to search API

lib/api/search.rb

@@ -35,6 +35,7 @@ module API
           state: params[:state],
           confidential: params[:confidential],
           snippets: snippets?,
+          basic_search: params[:basic_search],
           page: params[:page],
           per_page: params[:per_page]
         }.merge(additional_params)

spec/requests/api/search_spec.rb

@@ -516,6 +516,14 @@ RSpec.describe API::Search do
         end
       end
 
+      context 'when requesting basic search' do
+        it 'passes the parameter to search service' do
+          expect(SearchService).to receive(:new).with(user, hash_including(basic_search: 'true'))
+
+          get api(endpoint, user), params: { scope: 'issues', search: 'awesome', basic_search: 'true' }
+        end
+      end
+
       context 'for merge_requests scope' do
         let(:endpoint) { "/projects/#{repo_project.id}/search" }