require 'rails_helper'

module Tables
  RSpec.describe Shift do
    describe '#each' do
      let(:shifts) do
        acc = []
        described_class.new(initial_solution).each do |solution|
          acc << solution.tables.map(&:dup)
        end
        acc
      end

      context 'when there are two tables with two people each' do
        let(:initial_solution) do
          Distribution.new(min_per_table: 2, max_per_table: 2).tap do |distribution|
            distribution.tables << %i[a b].to_table
            distribution.tables << %i[c d].to_table
          end
        end

        it 'yields all possible shifts between the tables' do
          expect(shifts).to contain_exactly(
            [[:b], %i[c d a]],
            [[:a], %i[c d b]],
            [%i[b a d], [:c]],
            [%i[b a c], [:d]]
          )
        end
      end
    end
  end
end