Hash values not serialized

[clintonb]

The values of exposed hashes are not serialized. In the example below, a call to Person.serizable_hash() yields a hash with the key 'r:address' pointing to an Address entity instead of serializable_hash of the Address entity object.

require 'grape_entity'

class Address < Grape::Entity
  expose :street
  expose :city
end

class Person < Grape::Entity
  expose :name

  expose :_embedded do |person|
    {
      'r:address' => Address.new(person.address),
    }
  end
end

The solution I have come up with (and will PR shortly) is to update Grape::Entity.serializable_hash by adding a check for for Hash similar to what is done for Array:

def serializable_hash(runtime_options = {})
      return nil if object.nil?
      opts = options.merge(runtime_options || {})
      exposures.inject({}) do |output, (attribute, exposure_options)|
        if (exposure_options.has_key?(:proc) || object.respond_to?(attribute)) && conditions_met?(exposure_options, opts)
          partial_output = value_for(attribute, opts)
          output[key_for(attribute)] =
            if partial_output.respond_to? :serializable_hash
              partial_output.serializable_hash(runtime_options)
            elsif partial_output.kind_of?(Array) && !partial_output.map {|o| o.respond_to? :serializable_hash}.include?(false)
              partial_output.map {|o| o.serializable_hash}
            elsif partial_output.kind_of?(Hash)
              # Serialize exposed hashes
              partial_output.each do |key, value|
                partial_output[key] = value.serializable_hash if value.respond_to? :serializable_hash
              end
            else
              partial_output
            end
        end
        output
      end
    end

If there are suggestions for alternatives or improvements, or reasons why this functionality should not be included, please present them.

[dblock]

Seems like a legit bug.