require 'spec_helper' describe Gitlab::Serializer::Pagination do let(:request) { double(url: "#{Gitlab.config.gitlab.url}:8080/api/v4/projects?#{query.to_query}", query_parameters: query) } let(:response) { spy('response') } let(:headers) { spy('headers') } before do allow(response).to receive(:headers).and_return(headers) end let(:pagination) { described_class.new(request, response) } describe '#paginate' do subject { pagination.paginate(resource) } let(:resource) { User.all } let(:query) { { page: 1, per_page: 2 } } context 'when a multiple resources are present in relation' do before do create_list(:user, 3) end it 'correctly paginates the resource' do expect(subject.count).to be 2 end it 'appends relevant headers' do expect(headers).to receive(:[]=).with('X-Total', '3') expect(headers).to receive(:[]=).with('X-Total-Pages', '2') expect(headers).to receive(:[]=).with('X-Per-Page', '2') subject end end context 'when an invalid resource is about to be paginated' do let(:resource) { create(:user) } it 'raises error' do expect { subject }.to raise_error( described_class::InvalidResourceError) end end end end