# encoding: utf-8 require 'spec_helper' describe Algebra::Summarization, '.new' do subject { object.new(operand, summarize_per, summarizers) } let(:header) { [ [ :id, Integer ], [ :name, String ] ] } let(:operand) { Relation.new(header, [ [ 1, 'John Doe' ], [ 2, 'Jane Doe' ] ]) } let(:summarizers) { {} } let(:object) { described_class } context 'with a summarize_per that has a subset of the headers in the operand' do let(:summarize_per) { Relation.new([ [ :id, Integer ] ], [ [ 1 ], [ 2 ] ]) } it { should be_instance_of(object) } end context 'with a summarize_per that has equivalent headers to the headers in the operand' do let(:summarize_per) { operand } specify { expect { subject }.to raise_error(InvalidHeaderError, 'the summarize_per header must be a proper subset of the operand header') } end context 'with a summarize_per that has a superset of the headers in the operand' do let(:summarize_per) { Relation.new([ [ :id, Integer ], [ :name, String ] ], [ [ 1, 'Dan Kubb' ] ]) } specify { expect { subject }.to raise_error(InvalidHeaderError, 'the summarize_per header must be a proper subset of the operand header') } end end