# encoding: utf-8 require 'spec_helper' [ :difference, :- ].each do |method| describe Relation::Keys, "##{method}" do subject { object.send(method, other) } let(:object) { described_class.coerce([ header ]) } let(:other) { described_class.coerce([ other_header ]) } let(:header) { [ [ :id, Integer ] ] } context 'when the attributes overlap' do let(:other_header) { [ [ :id, Integer ] ] } it { should be_instance_of(described_class) } it { should be_empty } end context 'when the attributes do not overlap' do let(:other_header) { [ [ :name, String ] ] } it { should equal(object) } end end end