require 'spec_helper'

describe Immutable::List do
  describe '#add' do
    [
      [[], 'A', ['A']],
      [['A'], 'B', %w[B A]],
      [['A'], 'A', %w[A A]],
      [%w[A B C], 'D', %w[D A B C]],
    ].each do |values, new_value, expected|
      context "on #{values.inspect} with #{new_value.inspect}" do
        let(:list) { L[*values] }

        it 'preserves the original' do
          list.add(new_value)
          list.should eql(L[*values])
        end

        it "returns #{expected.inspect}" do
          list.add(new_value).should eql(L[*expected])
        end
      end
    end
  end
end