# encoding: utf-8

require 'spec_helper'

describe Algebra::Product, '#delete' do
  subject { object.delete(other) }

  let(:object) { described_class.new(left, right)                }
  let(:other)  { double('other')                                 }
  let(:left)   { Relation.new([[:id, Integer]], [[1]])           }
  let(:right)  { Relation.new([[:name, String]], [['John Doe']]) }

  specify { expect { subject }.to raise_error(ImmutableRelationError, 'deleting from a product is impossible') }
end