# 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