diff --git a/Gemfile b/Gemfile
index 21bb4f6..ce06b9a 100644
--- a/Gemfile
+++ b/Gemfile
@@ -1,4 +1,6 @@
-source 'https://rubygems.org'
+# frozen_string_literal: true
+
+source "https://rubygems.org"
 
 # Declare your gem's dependencies in options_model.gemspec.
 # Bundler will treat runtime dependencies like base dependencies, and
diff --git a/Rakefile b/Rakefile
index dfe9f11..de59ed3 100644
--- a/Rakefile
+++ b/Rakefile
@@ -1,33 +1,29 @@
+# frozen_string_literal: true
+
 begin
-  require 'bundler/setup'
+  require "bundler/setup"
 rescue LoadError
-  puts 'You must `gem install bundler` and `bundle install` to run rake tasks'
+  puts "You must `gem install bundler` and `bundle install` to run rake tasks"
 end
 
-require 'rdoc/task'
+require "rdoc/task"
 
 RDoc::Task.new(:rdoc) do |rdoc|
-  rdoc.rdoc_dir = 'rdoc'
-  rdoc.title    = 'OptionsModel'
-  rdoc.options << '--line-numbers'
-  rdoc.rdoc_files.include('README.md')
-  rdoc.rdoc_files.include('lib/**/*.rb')
+  rdoc.rdoc_dir = "rdoc"
+  rdoc.title    = "OptionsModel"
+  rdoc.options << "--line-numbers"
+  rdoc.rdoc_files.include("README.md")
+  rdoc.rdoc_files.include("lib/**/*.rb")
 end
 
+require "bundler/gem_tasks"
 
-
-
-
-
-require 'bundler/gem_tasks'
-
-require 'rake/testtask'
+require "rake/testtask"
 
 Rake::TestTask.new(:test) do |t|
-  t.libs << 'test'
-  t.pattern = 'test/**/*_test.rb'
+  t.libs << "test"
+  t.pattern = "test/**/*_test.rb"
   t.verbose = false
 end
 
-
 task default: :test
diff --git a/bin/test b/bin/test
index 2f98ca3..267eeaa 100755
--- a/bin/test
+++ b/bin/test
@@ -1,4 +1,6 @@
 #!/usr/bin/env ruby
+# frozen_string_literal: true
+
 $: << File.expand_path(File.expand_path("../../test", __FILE__))
 
 require "bundler/setup"
diff --git a/lib/options_model.rb b/lib/options_model.rb
index a9d5145..c5dfa2c 100644
--- a/lib/options_model.rb
+++ b/lib/options_model.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require "active_model"
 require "active_model/type"
 
@@ -9,5 +11,4 @@
 require "options_model/base"
 
 module OptionsModel
-
 end
diff --git a/lib/options_model/base.rb b/lib/options_model/base.rb
index 5b9fa44..db3e2ce 100644
--- a/lib/options_model/base.rb
+++ b/lib/options_model/base.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module OptionsModel
   class Base
     include ActiveModel::Model
diff --git a/lib/options_model/concerns/attribute_assignment.rb b/lib/options_model/concerns/attribute_assignment.rb
index 404669d..df5a0ed 100644
--- a/lib/options_model/concerns/attribute_assignment.rb
+++ b/lib/options_model/concerns/attribute_assignment.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module OptionsModel
   module Concerns
     module AttributeAssignment
diff --git a/lib/options_model/concerns/attributes.rb b/lib/options_model/concerns/attributes.rb
index 6eb610e..09f00ce 100644
--- a/lib/options_model/concerns/attributes.rb
+++ b/lib/options_model/concerns/attributes.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module OptionsModel
   module Concerns
     module Attributes
diff --git a/lib/options_model/concerns/name_hacking.rb b/lib/options_model/concerns/name_hacking.rb
index 407804c..901e2dc 100644
--- a/lib/options_model/concerns/name_hacking.rb
+++ b/lib/options_model/concerns/name_hacking.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module OptionsModel
   module Concerns
     module NameHacking
diff --git a/lib/options_model/concerns/serialization.rb b/lib/options_model/concerns/serialization.rb
index 92a765d..781397a 100644
--- a/lib/options_model/concerns/serialization.rb
+++ b/lib/options_model/concerns/serialization.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module OptionsModel
   module Concerns
     module Serialization
@@ -8,9 +10,11 @@ def to_h
 
         hash.merge! unused_attributes if self.class.with_unused_attributes?
         self.class.attribute_names_for_inlining.each do |name|
-          hash[name] = send(:"#{name}")
+          hash[name] = send(name)
+        end
+        self.class.attribute_names_for_nesting.each do |name|
+          hash[name] = send(name).to_h
         end
-        hash.merge! nested_attributes.reduce({}) { |h, (k, v)| h[k] = v.to_h; h }
 
         hash
       end
diff --git a/lib/options_model/version.rb b/lib/options_model/version.rb
index 7a00f43..26622f7 100644
--- a/lib/options_model/version.rb
+++ b/lib/options_model/version.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module OptionsModel
   VERSION = "0.0.5".freeze
 end
diff --git a/lib/tasks/options_model_tasks.rake b/lib/tasks/options_model_tasks.rake
index 1ab3133..f1e9920 100644
--- a/lib/tasks/options_model_tasks.rake
+++ b/lib/tasks/options_model_tasks.rake
@@ -1,3 +1,4 @@
+# frozen_string_literal: true
 # desc "Explaining what the task does"
 # task :options_model do
 #   # Task goes here
diff --git a/options_model.gemspec b/options_model.gemspec
index 7fafc1b..55a223e 100644
--- a/options_model.gemspec
+++ b/options_model.gemspec
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 $:.push File.expand_path("../lib", __FILE__)
 
 # Maintain your gem's version:
diff --git a/test/dummy/Rakefile b/test/dummy/Rakefile
index e85f913..d2a78aa 100644
--- a/test/dummy/Rakefile
+++ b/test/dummy/Rakefile
@@ -1,6 +1,8 @@
+# frozen_string_literal: true
+
 # Add your own tasks in files placed in lib/tasks ending in .rake,
 # for example lib/tasks/capistrano.rake, and they will automatically be available to Rake.
 
-require_relative 'config/application'
+require_relative "config/application"
 
 Rails.application.load_tasks
diff --git a/test/dummy/app/channels/application_cable/channel.rb b/test/dummy/app/channels/application_cable/channel.rb
index d672697..9aec230 100644
--- a/test/dummy/app/channels/application_cable/channel.rb
+++ b/test/dummy/app/channels/application_cable/channel.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module ApplicationCable
   class Channel < ActionCable::Channel::Base
   end
diff --git a/test/dummy/app/channels/application_cable/connection.rb b/test/dummy/app/channels/application_cable/connection.rb
index 0ff5442..8d6c2a1 100644
--- a/test/dummy/app/channels/application_cable/connection.rb
+++ b/test/dummy/app/channels/application_cable/connection.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 module ApplicationCable
   class Connection < ActionCable::Connection::Base
   end
diff --git a/test/dummy/app/controllers/application_controller.rb b/test/dummy/app/controllers/application_controller.rb
index 1c07694..280cc28 100644
--- a/test/dummy/app/controllers/application_controller.rb
+++ b/test/dummy/app/controllers/application_controller.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 class ApplicationController < ActionController::Base
   protect_from_forgery with: :exception
 end
diff --git a/test/dummy/app/helpers/application_helper.rb b/test/dummy/app/helpers/application_helper.rb
index de6be79..15b06f0 100644
--- a/test/dummy/app/helpers/application_helper.rb
+++ b/test/dummy/app/helpers/application_helper.rb
@@ -1,2 +1,4 @@
+# frozen_string_literal: true
+
 module ApplicationHelper
 end
diff --git a/test/dummy/app/jobs/application_job.rb b/test/dummy/app/jobs/application_job.rb
index a009ace..d92ffdd 100644
--- a/test/dummy/app/jobs/application_job.rb
+++ b/test/dummy/app/jobs/application_job.rb
@@ -1,2 +1,4 @@
+# frozen_string_literal: true
+
 class ApplicationJob < ActiveJob::Base
 end
diff --git a/test/dummy/bin/bundle b/test/dummy/bin/bundle
index 66e9889..277e128 100755
--- a/test/dummy/bin/bundle
+++ b/test/dummy/bin/bundle
@@ -1,3 +1,5 @@
 #!/usr/bin/env ruby
-ENV['BUNDLE_GEMFILE'] ||= File.expand_path('../../Gemfile', __FILE__)
-load Gem.bin_path('bundler', 'bundle')
+# frozen_string_literal: true
+
+ENV["BUNDLE_GEMFILE"] ||= File.expand_path("../../Gemfile", __FILE__)
+load Gem.bin_path("bundler", "bundle")
diff --git a/test/dummy/bin/rails b/test/dummy/bin/rails
index 0739660..22f2d8d 100755
--- a/test/dummy/bin/rails
+++ b/test/dummy/bin/rails
@@ -1,4 +1,6 @@
 #!/usr/bin/env ruby
-APP_PATH = File.expand_path('../config/application', __dir__)
-require_relative '../config/boot'
-require 'rails/commands'
+# frozen_string_literal: true
+
+APP_PATH = File.expand_path("../config/application", __dir__)
+require_relative "../config/boot"
+require "rails/commands"
diff --git a/test/dummy/bin/rake b/test/dummy/bin/rake
index 1724048..e436ea5 100755
--- a/test/dummy/bin/rake
+++ b/test/dummy/bin/rake
@@ -1,4 +1,6 @@
 #!/usr/bin/env ruby
-require_relative '../config/boot'
-require 'rake'
+# frozen_string_literal: true
+
+require_relative "../config/boot"
+require "rake"
 Rake.application.run
diff --git a/test/dummy/bin/setup b/test/dummy/bin/setup
index 93a2160..9b229da 100755
--- a/test/dummy/bin/setup
+++ b/test/dummy/bin/setup
@@ -1,10 +1,12 @@
 #!/usr/bin/env ruby
-require 'pathname'
-require 'fileutils'
+# frozen_string_literal: true
+
+require "pathname"
+require "fileutils"
 include FileUtils
 
 # path to your application root.
-APP_ROOT = Pathname.new File.expand_path('../../', __FILE__)
+APP_ROOT = Pathname.new File.expand_path("../../", __FILE__)
 
 def system!(*args)
   system(*args) || abort("\n== Command #{args} failed ==")
@@ -14,17 +16,16 @@ chdir APP_ROOT do
   # This script is a starting point to setup your application.
   # Add necessary setup steps to this file.
 
-  puts '== Installing dependencies =='
-  system! 'gem install bundler --conservative'
-  system('bundle check') || system!('bundle install')
+  puts "== Installing dependencies =="
+  system! "gem install bundler --conservative"
+  system("bundle check") || system!("bundle install")
 
   # Install JavaScript dependencies if using Yarn
   # system('bin/yarn')
 
-
   puts "\n== Removing old logs and tempfiles =="
-  system! 'bin/rails log:clear tmp:clear'
+  system! "bin/rails log:clear tmp:clear"
 
   puts "\n== Restarting application server =="
-  system! 'bin/rails restart'
+  system! "bin/rails restart"
 end
diff --git a/test/dummy/bin/update b/test/dummy/bin/update
index dc15867..d42bc68 100755
--- a/test/dummy/bin/update
+++ b/test/dummy/bin/update
@@ -1,10 +1,12 @@
 #!/usr/bin/env ruby
-require 'pathname'
-require 'fileutils'
+# frozen_string_literal: true
+
+require "pathname"
+require "fileutils"
 include FileUtils
 
 # path to your application root.
-APP_ROOT = Pathname.new File.expand_path('../../', __FILE__)
+APP_ROOT = Pathname.new File.expand_path("../../", __FILE__)
 
 def system!(*args)
   system(*args) || abort("\n== Command #{args} failed ==")
@@ -14,13 +16,13 @@ chdir APP_ROOT do
   # This script is a way to update your development environment automatically.
   # Add necessary update steps to this file.
 
-  puts '== Installing dependencies =='
-  system! 'gem install bundler --conservative'
-  system('bundle check') || system!('bundle install')
+  puts "== Installing dependencies =="
+  system! "gem install bundler --conservative"
+  system("bundle check") || system!("bundle install")
 
   puts "\n== Removing old logs and tempfiles =="
-  system! 'bin/rails log:clear tmp:clear'
+  system! "bin/rails log:clear tmp:clear"
 
   puts "\n== Restarting application server =="
-  system! 'bin/rails restart'
+  system! "bin/rails restart"
 end
diff --git a/test/dummy/bin/yarn b/test/dummy/bin/yarn
index c2bacef..c9b7498 100755
--- a/test/dummy/bin/yarn
+++ b/test/dummy/bin/yarn
@@ -1,5 +1,7 @@
 #!/usr/bin/env ruby
-VENDOR_PATH = File.expand_path('..', __dir__)
+# frozen_string_literal: true
+
+VENDOR_PATH = File.expand_path("..", __dir__)
 Dir.chdir(VENDOR_PATH) do
   begin
     exec "yarnpkg #{ARGV.join(" ")}"
diff --git a/test/dummy/config.ru b/test/dummy/config.ru
index f7ba0b5..bff88d6 100644
--- a/test/dummy/config.ru
+++ b/test/dummy/config.ru
@@ -1,5 +1,7 @@
+# frozen_string_literal: true
+
 # This file is used by Rack-based servers to start the application.
 
-require_relative 'config/environment'
+require_relative "config/environment"
 
 run Rails.application
diff --git a/test/dummy/config/application.rb b/test/dummy/config/application.rb
index 0a1c107..970e8ad 100644
--- a/test/dummy/config/application.rb
+++ b/test/dummy/config/application.rb
@@ -1,4 +1,6 @@
-require_relative 'boot'
+# frozen_string_literal: true
+
+require_relative "boot"
 
 # Pick the frameworks you want:
 # require "active_record/railtie"
@@ -23,4 +25,3 @@ class Application < Rails::Application
     # -- all .rb files in that directory are automatically loaded.
   end
 end
-
diff --git a/test/dummy/config/boot.rb b/test/dummy/config/boot.rb
index c9aef85..59459d4 100644
--- a/test/dummy/config/boot.rb
+++ b/test/dummy/config/boot.rb
@@ -1,5 +1,7 @@
+# frozen_string_literal: true
+
 # Set up gems listed in the Gemfile.
-ENV['BUNDLE_GEMFILE'] ||= File.expand_path('../../../Gemfile', __dir__)
+ENV["BUNDLE_GEMFILE"] ||= File.expand_path("../../../Gemfile", __dir__)
 
-require 'bundler/setup' if File.exist?(ENV['BUNDLE_GEMFILE'])
-$LOAD_PATH.unshift File.expand_path('../../../lib', __dir__)
+require "bundler/setup" if File.exist?(ENV["BUNDLE_GEMFILE"])
+$LOAD_PATH.unshift File.expand_path("../../../lib", __dir__)
diff --git a/test/dummy/config/environment.rb b/test/dummy/config/environment.rb
index 426333b..7df99e8 100644
--- a/test/dummy/config/environment.rb
+++ b/test/dummy/config/environment.rb
@@ -1,5 +1,7 @@
+# frozen_string_literal: true
+
 # Load the Rails application.
-require_relative 'application'
+require_relative "application"
 
 # Initialize the Rails application.
 Rails.application.initialize!
diff --git a/test/dummy/config/environments/development.rb b/test/dummy/config/environments/development.rb
index 97e9b96..e7d056d 100644
--- a/test/dummy/config/environments/development.rb
+++ b/test/dummy/config/environments/development.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 Rails.application.configure do
   # Settings specified here will take precedence over those in config/application.rb.
 
@@ -13,12 +15,12 @@
   config.consider_all_requests_local = true
 
   # Enable/disable caching. By default caching is disabled.
-  if Rails.root.join('tmp/caching-dev.txt').exist?
+  if Rails.root.join("tmp/caching-dev.txt").exist?
     config.action_controller.perform_caching = true
 
     config.cache_store = :memory_store
     config.public_file_server.headers = {
-      'Cache-Control' => "public, max-age=#{2.days.seconds.to_i}"
+      "Cache-Control" => "public, max-age=#{2.days.seconds.to_i}"
     }
   else
     config.action_controller.perform_caching = false
@@ -29,7 +31,6 @@
   # Print deprecation notices to the Rails logger.
   config.active_support.deprecation = :log
 
-
   # Raises error for missing translations
   # config.action_view.raise_on_missing_translations = true
 
diff --git a/test/dummy/config/environments/production.rb b/test/dummy/config/environments/production.rb
index 5dcdad9..78d2f09 100644
--- a/test/dummy/config/environments/production.rb
+++ b/test/dummy/config/environments/production.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 Rails.application.configure do
   # Settings specified here will take precedence over those in config/application.rb.
 
@@ -21,8 +23,7 @@
 
   # Disable serving static files from the `/public` folder by default since
   # Apache or NGINX already handles this.
-  config.public_file_server.enabled = ENV['RAILS_SERVE_STATIC_FILES'].present?
-
+  config.public_file_server.enabled = ENV["RAILS_SERVE_STATIC_FILES"].present?
 
   # Enable serving of images, stylesheets, and JavaScripts from an asset server.
   # config.action_controller.asset_host = 'http://assets.example.com'
diff --git a/test/dummy/config/environments/test.rb b/test/dummy/config/environments/test.rb
index 6fd7f98..454733e 100644
--- a/test/dummy/config/environments/test.rb
+++ b/test/dummy/config/environments/test.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 Rails.application.configure do
   # Settings specified here will take precedence over those in config/application.rb.
 
@@ -15,7 +17,7 @@
   # Configure public file server for tests with Cache-Control for performance.
   config.public_file_server.enabled = true
   config.public_file_server.headers = {
-    'Cache-Control' => "public, max-age=#{1.hour.seconds.to_i}"
+    "Cache-Control" => "public, max-age=#{1.hour.seconds.to_i}"
   }
 
   # Show full error reports and disable caching.
diff --git a/test/dummy/config/initializers/application_controller_renderer.rb b/test/dummy/config/initializers/application_controller_renderer.rb
index 51639b6..315ac48 100644
--- a/test/dummy/config/initializers/application_controller_renderer.rb
+++ b/test/dummy/config/initializers/application_controller_renderer.rb
@@ -1,3 +1,4 @@
+# frozen_string_literal: true
 # Be sure to restart your server when you modify this file.
 
 # ApplicationController.renderer.defaults.merge!(
diff --git a/test/dummy/config/initializers/backtrace_silencers.rb b/test/dummy/config/initializers/backtrace_silencers.rb
index 59385cd..d0f0d3b 100644
--- a/test/dummy/config/initializers/backtrace_silencers.rb
+++ b/test/dummy/config/initializers/backtrace_silencers.rb
@@ -1,3 +1,4 @@
+# frozen_string_literal: true
 # Be sure to restart your server when you modify this file.
 
 # You can add backtrace silencers for libraries that you're using but don't wish to see in your backtraces.
diff --git a/test/dummy/config/initializers/cookies_serializer.rb b/test/dummy/config/initializers/cookies_serializer.rb
index 5a6a32d..ee8dff9 100644
--- a/test/dummy/config/initializers/cookies_serializer.rb
+++ b/test/dummy/config/initializers/cookies_serializer.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 # Be sure to restart your server when you modify this file.
 
 # Specify a serializer for the signed and encrypted cookie jars.
diff --git a/test/dummy/config/initializers/filter_parameter_logging.rb b/test/dummy/config/initializers/filter_parameter_logging.rb
index 4a994e1..7a4f47b 100644
--- a/test/dummy/config/initializers/filter_parameter_logging.rb
+++ b/test/dummy/config/initializers/filter_parameter_logging.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 # Be sure to restart your server when you modify this file.
 
 # Configure sensitive parameters which will be filtered from the log file.
diff --git a/test/dummy/config/initializers/inflections.rb b/test/dummy/config/initializers/inflections.rb
index ac033bf..aa7435f 100644
--- a/test/dummy/config/initializers/inflections.rb
+++ b/test/dummy/config/initializers/inflections.rb
@@ -1,3 +1,4 @@
+# frozen_string_literal: true
 # Be sure to restart your server when you modify this file.
 
 # Add new inflection rules using the following format. Inflections
diff --git a/test/dummy/config/initializers/mime_types.rb b/test/dummy/config/initializers/mime_types.rb
index dc18996..6e1d16f 100644
--- a/test/dummy/config/initializers/mime_types.rb
+++ b/test/dummy/config/initializers/mime_types.rb
@@ -1,3 +1,4 @@
+# frozen_string_literal: true
 # Be sure to restart your server when you modify this file.
 
 # Add new mime types for use in respond_to blocks:
diff --git a/test/dummy/config/initializers/wrap_parameters.rb b/test/dummy/config/initializers/wrap_parameters.rb
index 633c1c8..e7148a3 100644
--- a/test/dummy/config/initializers/wrap_parameters.rb
+++ b/test/dummy/config/initializers/wrap_parameters.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 # Be sure to restart your server when you modify this file.
 
 # This file contains settings for ActionController::ParamsWrapper which
diff --git a/test/dummy/config/puma.rb b/test/dummy/config/puma.rb
index 1e19380..55bd3da 100644
--- a/test/dummy/config/puma.rb
+++ b/test/dummy/config/puma.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 # Puma can serve each request in a thread from an internal thread pool.
 # The `threads` method setting takes two numbers: a minimum and maximum.
 # Any libraries that use thread pools should be configured to match
diff --git a/test/dummy/config/routes.rb b/test/dummy/config/routes.rb
index 787824f..47cc16e 100644
--- a/test/dummy/config/routes.rb
+++ b/test/dummy/config/routes.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 Rails.application.routes.draw do
   # For details on the DSL available within this file, see http://guides.rubyonrails.org/routing.html
 end
diff --git a/test/dummy/config/spring.rb b/test/dummy/config/spring.rb
index c9119b4..ff5ba06 100644
--- a/test/dummy/config/spring.rb
+++ b/test/dummy/config/spring.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 %w(
   .ruby-version
   .rbenv-vars
diff --git a/test/options_model_test.rb b/test/options_model_test.rb
index 70ff2fd..2e32c1e 100644
--- a/test/options_model_test.rb
+++ b/test/options_model_test.rb
@@ -1,4 +1,6 @@
-require 'test_helper'
+# frozen_string_literal: true
+
+require "test_helper"
 
 class OptionsModel::Test < ActiveSupport::TestCase
   test "truth" do
diff --git a/test/test_helper.rb b/test/test_helper.rb
index 36d839d..078c5a9 100644
--- a/test/test_helper.rb
+++ b/test/test_helper.rb
@@ -1,3 +1,5 @@
+# frozen_string_literal: true
+
 require File.expand_path("../../test/dummy/config/environment.rb", __FILE__)
 require "rails/test_help"
 
@@ -5,7 +7,7 @@
 # to be shown.
 Minitest.backtrace_filter = Minitest::BacktraceFilter.new
 
-Rails::TestUnitReporter.executable = 'bin/test'
+Rails::TestUnitReporter.executable = "bin/test"
 
 # Load fixtures from the engine
 if ActiveSupport::TestCase.respond_to?(:fixture_path=)