require 'spec_helper' describe Gitlab::MultiCollectionPaginator do subject(:paginator) { described_class.new(Project.all.order(:id), Group.all.order(:id), per_page: 3) } it 'combines both collections' do project = create(:project) group = create(:group) expect(paginator.paginate(1)).to eq([project, group]) end it 'includes elements second collection if first collection is empty' do group = create(:group) expect(paginator.paginate(1)).to eq([group]) end context 'with a full first page' do let!(:all_groups) { create_list(:group, 4) } let!(:all_projects) { create_list(:project, 4) } it 'knows the total count of the collection' do expect(paginator.total_count).to eq(8) end it 'fills the first page with elements of the first collection' do expect(paginator.paginate(1)).to eq(all_projects.take(3)) end it 'fils the second page with a mixture of the first & second collection' do first_collection_element = all_projects.last second_collection_elements = all_groups.take(2) expected_collection = [first_collection_element] + second_collection_elements expect(paginator.paginate(2)).to eq(expected_collection) end it 'fils the last page with elements from the second collection' do expected_collection = all_groups[-2..-1] expect(paginator.paginate(3)).to eq(expected_collection) end end end