require 'spec_helper'

describe Immutable::List do
  [:map, :collect].each do |method|
    describe "##{method}" do
      it 'is lazy' do
        -> { Immutable.stream { fail }.map { |item| item } }.should_not raise_error
      end

      [
        [[], []],
        [['A'], ['a']],
        [%w[A B C], %w[a b c]],
      ].each do |values, expected|
        context "on #{values.inspect}" do
          let(:list) { L[*values] }

          context 'with a block' do
            it 'preserves the original' do
              list.send(method, &:downcase)
              list.should eql(L[*values])
            end

            it "returns #{expected.inspect}" do
              list.send(method, &:downcase).should eql(L[*expected])
            end

            it 'is lazy' do
              count = 0
              list.send(method) { |item| count += 1 }
              count.should <= 1
            end
          end

          context 'without a block' do
            it 'returns an Enumerator' do
              list.send(method).class.should be(Enumerator)
              list.send(method).each(&:downcase).should eql(L[*expected])
            end
          end
        end
      end
    end
  end
end
