require 'spec_helper'

describe Immutable::Deque do
  describe '.[]' do
    context 'with no arguments' do
      it 'always returns the same instance' do
        D[].class.should be(Immutable::Deque)
        D[].should equal(D[])
      end

      it 'returns an empty, frozen deque' do
        D[].should be_empty
        D[].should be_frozen
      end
    end

    context 'with a number of items' do
      let(:deque) { D['A', 'B', 'C'] }

      it 'always returns a different instance' do
        deque.should_not equal(D['A', 'B', 'C'])
      end

      it 'is the same as repeatedly using #endeque' do
        deque.should eql(D.empty.enqueue('A').enqueue('B').enqueue('C'))
      end
    end
  end
end