A sexy version of Hash that strips whitespace from string keys. #StripperHash

stripper_hash.rb

class Hash
  def strip
    StripperHash.new(self)
  end
end

class StripperHash < Hash
  def initialize(constructor = {})
    if constructor.respond_to?(:to_hash)
      super
      merge!(constructor)
    else
      super(constructor)
    end
  end

  def []=(key, value)
    super(key.strip, value)
  end

  alias_method :store, :[]=

  def merge(other_hash)
    super(strip(other_hash))
  end

  alias_method :update, :merge

  def merge!(other_hash)
    super(strip(other_hash))
  end

  def replace(other_hash)
    super(strip(other_hash))
  end

  private
  def strip(hash)
    stripped_hash = hash.dup

    hash.each_key do |key|
      if key.is_a?(String) && (stripped_key = key.strip) && key != stripped_key
        stripped_hash[stripped_key] = stripped_hash.delete(key)
      end
    end

    stripped_hash
  end
end

>> h = { 'test   ' => 1, test: 2 }
=> {"test   "=>1, :test=>2}

>> sh = h.strip
=> {:test=>2, "test"=>1}

>> sh.class
=> StripperHash

>> sh = StripperHash.new('test   ' => 1, test: 2)
=> {:test=>2, "test"=>1}

>> sh['test2  '] = 3
=> 3

>> sh
=> {:test=>2, "test"=>1, "test2"=>3}