Hash の key を camelize するやつ

hash_camelize_keys.rb

# -*- coding: utf-8 -*-

require 'active_support/core_ext'

class Hash
  def camelize_keys(first_letter = :upper)
    dup.camelize_keys!(first_letter)
  end

  def camelize_keys!(first_letter = :upper)
    keys.each do |key|
      self[key.to_s.camelize(first_letter)] = delete(key)
    end
    self
  end

  def deep_camelize_keys(first_letter = :upper)
    dup.deep_camelize_keys!(first_letter)
  end

  def deep_camelize_keys!(first_letter = :upper)
    keys.each do |key|
      value = delete(key)
      self[key.to_s.camelize(first_letter)] = value.is_a?(Hash) ? value.deep_camelize_keys(first_letter) : value
    end
    self
  end
end

status = {
  id: 1,
  text: 'にゃーん',
  user: {
    screen_name: 'mitukiii',
  },
  created_at: Time.now,
}

p status
p status.camelize_keys
p status.camelize_keys(:lower)
p status.deep_camelize_keys
p status.deep_camelize_keys(:lower)