require 'spec_helper'

describe Immutable::Set do
  describe '#clear' do
    [
      [],
      ['A'],
      %w[A B C],
    ].each do |values|
      describe "on #{values}" do
        let(:set) { S[*values] }

        it 'preserves the original' do
          set.clear
          set.should eql(S[*values])
        end

        it 'returns an empty set' do
          set.clear.should equal(S.empty)
        end
      end
    end

    context 'from a subclass' do
      it 'returns an empty instance of the subclass' do
        subclass = Class.new(Immutable::Set)
        instance = subclass.new([:a, :b, :c, :d])
        instance.clear.class.should be(subclass)
        instance.clear.should be_empty
      end
    end
  end
end