random look at ActiveSupport::OrderedHash versus HashWithIndifferentAccess

test_ordered_with_indifferent_access.rb

require 'rubygems'
require 'minitest/spec'
require 'minitest/autorun'
require 'minitest/reporters'
MiniTest::Unit.runner = MiniTest::SuiteRunner.new
MiniTest::Unit.runner.reporters << MiniTest::Reporters::SpecReporter.new
require 'securerandom'
require 'active_support/core_ext'

seen = []

keys = []
10.times do
  k = SecureRandom.hex(2)
  while seen.include?(k)
    k = SecureRandom.hex(2)
  end
  seen << k
  if rand > 0.5
    k = k.to_sym
  end
  keys << k
end

normal_hsh = {}
ordered_hsh = ActiveSupport::OrderedHash.new
keys.each do |k|
  v = rand(1e11)
  normal_hsh[k] = v
  ordered_hsh[k] = v
end

describe "key order" do
  describe "in normal hashes" do
    it "won't stay the same (unless we're in 1.9)" do
      if RUBY_VERSION >= '1.9'
        normal_hsh.keys.must_equal keys
      else
        normal_hsh.keys.wont_equal keys
      end
    end
    it "won't stay the same when converted to hash with indiff access (duh)" do
      normal_hsh.with_indifferent_access.keys.wont_equal keys.map(&:to_s)
    end
  end
  describe "with ActiveSupport::OrderedHash" do
    it "will stay the same" do
      ordered_hsh.keys.must_equal keys
    end
    it "will stay the same when converted to hash with indiff access" do
      ordered_hsh.with_indifferent_access.keys.must_equal keys.map(&:to_s)
    end
  end
end