# encoding: utf-8 require 'spec_helper' describe Optimizer::Algebra::Restriction::Contradiction, '#optimize' do subject { object.optimize } let(:header) { Relation::Header.coerce([[:id, Integer]]) } let(:base) { Relation.new(header, LazyEnumerable.new([[1]])) } let(:predicate) { Function::Proposition::Contradiction.instance } let(:relation) { base.restrict { predicate } } let(:object) { described_class.new(relation) } before do expect(object).to be_optimizable end it { should be_kind_of(Relation::Empty) } its(:header) { should be(header) } end