require 'spec_helper'

describe Immutable::Vector do
  describe '#each_index' do
    let(:vector) { V[1,2,3,4] }

    context 'with a block' do
      it 'yields all the valid indices into the vector' do
        result = []
        vector.each_index { |i| result << i }
        result.should eql([0,1,2,3])
      end

      it 'returns self' do
        vector.each_index {}.should be(vector)
      end
    end

    context 'without a block' do
      it 'returns an Enumerator' do
        vector.each_index.class.should be(Enumerator)
        vector.each_index.to_a.should eql([0,1,2,3])
      end
    end

    context 'on an empty vector' do
      it "doesn't yield anything" do
        V.empty.each_index { fail }
      end
    end

    [1, 2, 10, 31, 32, 33, 1000, 1024, 1025].each do |size|
      context "on a #{size}-item vector" do
        it 'yields all valid indices' do
          V.new(1..size).each_index.to_a.should == (0..(size-1)).to_a
        end
      end
    end
  end
end