diff --git a/.travis.yml b/.travis.yml
index 43ec68d..65f91e5 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -1,12 +1,27 @@
 sudo: false
 language: ruby
+
+bundler_args: --without guard --path=.bundle
+before_script: "./setup.sh install"
+script: "bundle exec rspec"
+
 rvm:
   - 2.2
   - 2.3
   - 2.4
 
+env:
+  - APP=rails_42
+  - APP=rails_42_sprockets_rails_3
+  - APP=rails_50
+  - APP=rails_51
+  - APP=rails_52
+
 matrix:
   fast_finish: true
+  include:
+    - rvm: 2.4
+      env: APP=rails_master
 
 cache:
   directories:
@@ -15,5 +30,5 @@ cache:
   - spec/railsapps/rails_42_sprockets_rails_3/.bundle
   - spec/railsapps/rails_50/.bundle
   - spec/railsapps/rails_51/.bundle
-bundler_args: --without guard --path=.bundle
-script: "rake"
+  - spec/railsapps/rails_52/.bundle
+  - spec/railsapps/rails_master/.bundle
diff --git a/roadie-rails.gemspec b/roadie-rails.gemspec
index 127364a..1dd8325 100644
--- a/roadie-rails.gemspec
+++ b/roadie-rails.gemspec
@@ -22,9 +22,9 @@ Gem::Specification.new do |spec|
   spec.require_paths = ["lib"]
 
   spec.add_dependency "roadie", "~> 3.1"
-  spec.add_dependency "railties", ">= 3.0", "< 5.2"
+  spec.add_dependency "railties", ">= 3.0", "< 6.1"
 
-  spec.add_development_dependency "rails", ">= 4.2", "< 5.2"
+  spec.add_development_dependency "rails", ">= 4.2", "< 6.1"
   spec.add_development_dependency "bundler", "~> 1.6"
   spec.add_development_dependency "rspec", "~> 3.0"
   spec.add_development_dependency "rspec-rails"
diff --git a/setup.sh b/setup.sh
index 0a56e6a..be09596 100755
--- a/setup.sh
+++ b/setup.sh
@@ -32,7 +32,8 @@ if [[ $1 == "install" ]]; then
   header "Installing gem dependencies"
   install
 
-  for app_path in $root/spec/railsapps/rails_*; do
+  app="${APP:-rails_*}"
+  for app_path in $root/spec/railsapps/$app; do
     (
       header "Rails app $(basename $app_path)"
       cd $app_path
@@ -46,7 +47,8 @@ elif [[ $1 == "update" ]]; then
   header "Updating gem dependencies"
   update
 
-  for app_path in $root/spec/railsapps/rails_*; do
+  app="${APP:-rails_*}"
+  for app_path in $root/spec/railsapps/$app; do
     (
       cd $app_path
       header "Updating $(basename $app_path)"
diff --git a/spec/integration_spec.rb b/spec/integration_spec.rb
index 57274b7..2ba01ad 100644
--- a/spec/integration_spec.rb
+++ b/spec/integration_spec.rb
@@ -11,9 +11,15 @@ def parse_html_in_email(mail)
     RailsApp.new("Rails 4.2.x", 'rails_42', runner: :bin, asset_pipeline: true, digests: false),
     RailsApp.new("Rails 4.2.x (with sprockets-rails 3)", 'rails_42_sprockets_rails_3', runner: :bin, asset_pipeline: true, digests: true, sprockets: 3),
     RailsApp.new("Rails 5.0.x", 'rails_50', runner: :bin, asset_pipeline: true, digests: true, sprockets: 3),
-    RailsApp.new("Rails 5.1.0", 'rails_51', runner: :bin, asset_pipeline: true, digests: true, sprockets: 3)
+    RailsApp.new("Rails 5.1.0", 'rails_51', runner: :bin, asset_pipeline: true, digests: true, sprockets: 3),
+    RailsApp.new("Rails 5.2.0", 'rails_52', runner: :bin, asset_pipeline: true, digests: true, sprockets: 3),
+    RailsApp.new("Rails master", 'rails_master', runner: :bin, asset_pipeline: true, digests: true, sprockets: 3)
   ]
 
+  if app = ENV['APP']
+    rails_apps.select! { |a| a.path == app }
+  end
+
   rails_apps.each do |app|
     describe "with #{app}" do
       before { app.reset }
diff --git a/spec/railsapps/rails_52/.gitignore b/spec/railsapps/rails_52/.gitignore
new file mode 100644
index 0000000..48fb168
--- /dev/null
+++ b/spec/railsapps/rails_52/.gitignore
@@ -0,0 +1,17 @@
+# See https://help.github.com/articles/ignoring-files for more about ignoring files.
+#
+# If you find yourself ignoring temporary files generated by your text editor
+# or operating system, you probably want to add a global ignore instead:
+#   git config --global core.excludesfile '~/.gitignore_global'
+
+# Ignore bundler config.
+/.bundle
+
+# Ignore all logfiles and tempfiles.
+/log/*
+/tmp/*
+!/log/.keep
+!/tmp/.keep
+
+# Ignore Byebug command history file.
+.byebug_history
diff --git a/spec/railsapps/rails_52/Gemfile b/spec/railsapps/rails_52/Gemfile
new file mode 100644
index 0000000..16d528b
--- /dev/null
+++ b/spec/railsapps/rails_52/Gemfile
@@ -0,0 +1,8 @@
+source 'https://rubygems.org'
+
+gem 'rails', '~> 5.2.0.rc1'
+gem 'sass-rails'
+gem 'sprockets-rails'
+gem 'listen'
+
+gem 'roadie-rails', path: '../../..'
diff --git a/spec/railsapps/rails_52/app/assets/images/rails.png b/spec/railsapps/rails_52/app/assets/images/rails.png
new file mode 100644
index 0000000..d5edc04
Binary files /dev/null and b/spec/railsapps/rails_52/app/assets/images/rails.png differ
diff --git a/spec/railsapps/rails_52/app/assets/stylesheets/email.css.scss b/spec/railsapps/rails_52/app/assets/stylesheets/email.css.scss
new file mode 100644
index 0000000..8fb351f
--- /dev/null
+++ b/spec/railsapps/rails_52/app/assets/stylesheets/email.css.scss
@@ -0,0 +1,2 @@
+body { background-color: green; }
+.image { background: image-url("rails.png"); }
diff --git a/spec/railsapps/rails_52/app/mailers/auto_mailer.rb b/spec/railsapps/rails_52/app/mailers/auto_mailer.rb
new file mode 100644
index 0000000..81f522e
--- /dev/null
+++ b/spec/railsapps/rails_52/app/mailers/auto_mailer.rb
@@ -0,0 +1,27 @@
+class AutoMailer < ActionMailer::Base
+  include Roadie::Rails::Automatic
+
+  default from: 'john@example.com'
+
+  def normal_email
+    generate_email
+  end
+
+  def disabled_email
+    generate_email
+  end
+
+  private
+  def roadie_options
+    unless action_name =~ /disabled/
+      super.combine(url_options: {protocol: "https"})
+    end
+  end
+
+  def generate_email
+    mail(to: 'example@example.org', subject: "Notification for you") do |format|
+      format.html { render :normal_email }
+      format.text { render :normal_email }
+    end
+  end
+end
diff --git a/spec/railsapps/rails_52/app/mailers/mailer.rb b/spec/railsapps/rails_52/app/mailers/mailer.rb
new file mode 100644
index 0000000..87cbb8a
--- /dev/null
+++ b/spec/railsapps/rails_52/app/mailers/mailer.rb
@@ -0,0 +1,17 @@
+class Mailer < ActionMailer::Base
+  include Roadie::Rails::Mailer
+
+  default from: 'john@example.com'
+
+  def normal_email
+    roadie_mail(to: 'example@example.org', subject: "Notification for you") do |format|
+      format.html
+      format.text
+    end
+  end
+
+  private
+  def roadie_options
+    super.combine(url_options: {protocol: "https"})
+  end
+end
diff --git a/spec/railsapps/rails_52/app/views/auto_mailer/normal_email.html.erb b/spec/railsapps/rails_52/app/views/auto_mailer/normal_email.html.erb
new file mode 100644
index 0000000..cf672b4
--- /dev/null
+++ b/spec/railsapps/rails_52/app/views/auto_mailer/normal_email.html.erb
@@ -0,0 +1,11 @@
+<!DOCTYPE html>
+<html>
+  <head>
+    <meta http-equiv="content-type" content="text/html; charset=utf-8">
+    <%= stylesheet_link_tag "email" %>
+  </head>
+  <body>
+    <h1>Normal email</h1>
+    <div class="image"></div>
+  </body>
+</html>
diff --git a/spec/railsapps/rails_52/app/views/auto_mailer/normal_email.text b/spec/railsapps/rails_52/app/views/auto_mailer/normal_email.text
new file mode 100644
index 0000000..302fdf4
--- /dev/null
+++ b/spec/railsapps/rails_52/app/views/auto_mailer/normal_email.text
@@ -0,0 +1 @@
+Normal email
diff --git a/spec/railsapps/rails_52/app/views/mailer/normal_email.html.erb b/spec/railsapps/rails_52/app/views/mailer/normal_email.html.erb
new file mode 100644
index 0000000..cf672b4
--- /dev/null
+++ b/spec/railsapps/rails_52/app/views/mailer/normal_email.html.erb
@@ -0,0 +1,11 @@
+<!DOCTYPE html>
+<html>
+  <head>
+    <meta http-equiv="content-type" content="text/html; charset=utf-8">
+    <%= stylesheet_link_tag "email" %>
+  </head>
+  <body>
+    <h1>Normal email</h1>
+    <div class="image"></div>
+  </body>
+</html>
diff --git a/spec/railsapps/rails_52/app/views/mailer/normal_email.text b/spec/railsapps/rails_52/app/views/mailer/normal_email.text
new file mode 100644
index 0000000..302fdf4
--- /dev/null
+++ b/spec/railsapps/rails_52/app/views/mailer/normal_email.text
@@ -0,0 +1 @@
+Normal email
diff --git a/spec/railsapps/rails_52/bin/rails b/spec/railsapps/rails_52/bin/rails
new file mode 100755
index 0000000..5191e69
--- /dev/null
+++ b/spec/railsapps/rails_52/bin/rails
@@ -0,0 +1,4 @@
+#!/usr/bin/env ruby
+APP_PATH = File.expand_path('../../config/application', __FILE__)
+require_relative '../config/boot'
+require 'rails/commands'
diff --git a/spec/railsapps/rails_52/config.ru b/spec/railsapps/rails_52/config.ru
new file mode 100644
index 0000000..f7ba0b5
--- /dev/null
+++ b/spec/railsapps/rails_52/config.ru
@@ -0,0 +1,5 @@
+# This file is used by Rack-based servers to start the application.
+
+require_relative 'config/environment'
+
+run Rails.application
diff --git a/spec/railsapps/rails_52/config/application.rb b/spec/railsapps/rails_52/config/application.rb
new file mode 100644
index 0000000..9c3923a
--- /dev/null
+++ b/spec/railsapps/rails_52/config/application.rb
@@ -0,0 +1,16 @@
+require_relative 'boot'
+
+require 'action_controller/railtie'
+require 'action_mailer/railtie'
+require 'action_view/railtie'
+require 'sprockets/railtie'
+
+# Require the gems listed in Gemfile, including any gems
+# you've limited to :test, :development, or :production.
+Bundler.require(*Rails.groups)
+
+module Rails52
+  class Application < Rails::Application
+    config.roadie.url_options = { host: 'example.app.org' }
+  end
+end
diff --git a/spec/railsapps/rails_52/config/boot.rb b/spec/railsapps/rails_52/config/boot.rb
new file mode 100644
index 0000000..30f5120
--- /dev/null
+++ b/spec/railsapps/rails_52/config/boot.rb
@@ -0,0 +1,3 @@
+ENV['BUNDLE_GEMFILE'] ||= File.expand_path('../Gemfile', __dir__)
+
+require 'bundler/setup' # Set up gems listed in the Gemfile.
diff --git a/spec/railsapps/rails_52/config/environment.rb b/spec/railsapps/rails_52/config/environment.rb
new file mode 100644
index 0000000..426333b
--- /dev/null
+++ b/spec/railsapps/rails_52/config/environment.rb
@@ -0,0 +1,5 @@
+# Load the Rails application.
+require_relative 'application'
+
+# Initialize the Rails application.
+Rails.application.initialize!
diff --git a/spec/railsapps/rails_52/config/environments/development.rb b/spec/railsapps/rails_52/config/environments/development.rb
new file mode 100644
index 0000000..58d20de
--- /dev/null
+++ b/spec/railsapps/rails_52/config/environments/development.rb
@@ -0,0 +1,51 @@
+Rails.application.configure do
+  # Settings specified here will take precedence over those in config/application.rb.
+
+  # In the development environment your application's code is reloaded on
+  # every request. This slows down response time but is perfect for development
+  # since you don't have to restart the web server when you make code changes.
+  config.cache_classes = false
+
+  # Do not eager load code on boot.
+  config.eager_load = false
+
+  # Show full error reports.
+  config.consider_all_requests_local = true
+
+  # Enable/disable caching. By default caching is disabled.
+  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=172800'
+    }
+  else
+    config.action_controller.perform_caching = false
+
+    config.cache_store = :null_store
+  end
+
+  # Don't care if the mailer can't send.
+  config.action_mailer.raise_delivery_errors = false
+
+  config.action_mailer.perform_caching = false
+
+  # Print deprecation notices to the Rails logger.
+  config.active_support.deprecation = :log
+
+  # Debug mode disables concatenation and preprocessing of assets.
+  # This option may cause significant delays in view rendering with a large
+  # number of complex assets.
+  config.assets.debug = true
+
+  # Suppress logger output for asset requests.
+  config.assets.quiet = true
+
+  # Raises error for missing translations
+  # config.action_view.raise_on_missing_translations = true
+
+  # Use an evented file watcher to asynchronously detect changes in source code,
+  # routes, locales, etc. This feature depends on the listen gem.
+  config.file_watcher = ActiveSupport::EventedFileUpdateChecker
+end
diff --git a/spec/railsapps/rails_52/config/environments/production.rb b/spec/railsapps/rails_52/config/environments/production.rb
new file mode 100644
index 0000000..7dabce6
--- /dev/null
+++ b/spec/railsapps/rails_52/config/environments/production.rb
@@ -0,0 +1,83 @@
+Rails.application.configure do
+  # Settings specified here will take precedence over those in config/application.rb.
+
+  # Code is not reloaded between requests.
+  config.cache_classes = true
+
+  # Eager load code on boot. This eager loads most of Rails and
+  # your application in memory, allowing both threaded web servers
+  # and those relying on copy on write to perform better.
+  # Rake tasks automatically ignore this option for performance.
+  config.eager_load = true
+
+  # Full error reports are disabled and caching is turned on.
+  config.consider_all_requests_local       = false
+  config.action_controller.perform_caching = true
+
+  # 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?
+
+  # Compress JavaScripts and CSS.
+  config.assets.js_compressor = :uglifier
+  # config.assets.css_compressor = :sass
+
+  # Do not fallback to assets pipeline if a precompiled asset is missed.
+  config.assets.compile = false
+
+  # `config.assets.precompile` and `config.assets.version` have moved to config/initializers/assets.rb
+
+  # Enable serving of images, stylesheets, and JavaScripts from an asset server.
+  # config.action_controller.asset_host = 'http://assets.example.com'
+
+  # Specifies the header that your server uses for sending files.
+  # config.action_dispatch.x_sendfile_header = 'X-Sendfile' # for Apache
+  # config.action_dispatch.x_sendfile_header = 'X-Accel-Redirect' # for NGINX
+
+  # Mount Action Cable outside main process or domain
+  # config.action_cable.mount_path = nil
+  # config.action_cable.url = 'wss://example.com/cable'
+  # config.action_cable.allowed_request_origins = [ 'http://example.com', /http:\/\/example.*/ ]
+
+  # Force all access to the app over SSL, use Strict-Transport-Security, and use secure cookies.
+  # config.force_ssl = true
+
+  # Use the lowest log level to ensure availability of diagnostic information
+  # when problems arise.
+  config.log_level = :debug
+
+  # Prepend all log lines with the following tags.
+  config.log_tags = [ :request_id ]
+
+  # Use a different cache store in production.
+  # config.cache_store = :mem_cache_store
+
+  # Use a real queuing backend for Active Job (and separate queues per environment)
+  # config.active_job.queue_adapter     = :resque
+  # config.active_job.queue_name_prefix = "rails_51_#{Rails.env}"
+  config.action_mailer.perform_caching = false
+
+  # Ignore bad email addresses and do not raise email delivery errors.
+  # Set this to true and configure the email server for immediate delivery to raise delivery errors.
+  # config.action_mailer.raise_delivery_errors = false
+
+  # Enable locale fallbacks for I18n (makes lookups for any locale fall back to
+  # the I18n.default_locale when a translation cannot be found).
+  config.i18n.fallbacks = true
+
+  # Send deprecation notices to registered listeners.
+  config.active_support.deprecation = :notify
+
+  # Use default logging formatter so that PID and timestamp are not suppressed.
+  config.log_formatter = ::Logger::Formatter.new
+
+  # Use a different logger for distributed setups.
+  # require 'syslog/logger'
+  # config.logger = ActiveSupport::TaggedLogging.new(Syslog::Logger.new 'app-name')
+
+  if ENV["RAILS_LOG_TO_STDOUT"].present?
+    logger           = ActiveSupport::Logger.new(STDOUT)
+    logger.formatter = config.log_formatter
+    config.logger = ActiveSupport::TaggedLogging.new(logger)
+  end
+end
diff --git a/spec/railsapps/rails_52/config/environments/test.rb b/spec/railsapps/rails_52/config/environments/test.rb
new file mode 100644
index 0000000..30587ef
--- /dev/null
+++ b/spec/railsapps/rails_52/config/environments/test.rb
@@ -0,0 +1,42 @@
+Rails.application.configure do
+  # Settings specified here will take precedence over those in config/application.rb.
+
+  # The test environment is used exclusively to run your application's
+  # test suite. You never need to work with it otherwise. Remember that
+  # your test database is "scratch space" for the test suite and is wiped
+  # and recreated between test runs. Don't rely on the data there!
+  config.cache_classes = true
+
+  # Do not eager load code on boot. This avoids loading your whole application
+  # just for the purpose of running a single test. If you are using a tool that
+  # preloads Rails for running tests, you may have to set it to true.
+  config.eager_load = false
+
+  # 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=3600'
+  }
+
+  # Show full error reports and disable caching.
+  config.consider_all_requests_local       = true
+  config.action_controller.perform_caching = false
+
+  # Raise exceptions instead of rendering exception templates.
+  config.action_dispatch.show_exceptions = false
+
+  # Disable request forgery protection in test environment.
+  config.action_controller.allow_forgery_protection = false
+  config.action_mailer.perform_caching = false
+
+  # Tell Action Mailer not to deliver emails to the real world.
+  # The :test delivery method accumulates sent emails in the
+  # ActionMailer::Base.deliveries array.
+  config.action_mailer.delivery_method = :test
+
+  # Print deprecation notices to the stderr.
+  config.active_support.deprecation = :stderr
+
+  # Raises error for missing translations
+  # config.action_view.raise_on_missing_translations = true
+end
diff --git a/spec/railsapps/rails_52/config/initializers/application_controller_renderer.rb b/spec/railsapps/rails_52/config/initializers/application_controller_renderer.rb
new file mode 100644
index 0000000..51639b6
--- /dev/null
+++ b/spec/railsapps/rails_52/config/initializers/application_controller_renderer.rb
@@ -0,0 +1,6 @@
+# Be sure to restart your server when you modify this file.
+
+# ApplicationController.renderer.defaults.merge!(
+#   http_host: 'example.org',
+#   https: false
+# )
diff --git a/spec/railsapps/rails_52/config/initializers/assets.rb b/spec/railsapps/rails_52/config/initializers/assets.rb
new file mode 100644
index 0000000..8bf3ad0
--- /dev/null
+++ b/spec/railsapps/rails_52/config/initializers/assets.rb
@@ -0,0 +1,11 @@
+# Be sure to restart your server when you modify this file.
+
+# Version of your assets, change this if you want to expire all your assets.
+Rails.application.config.assets.version = '1.0'
+
+# Add additional assets to the asset load path
+# Rails.application.config.assets.paths << Emoji.images_path
+
+# Precompile additional assets.
+# application.js, application.css, and all non-JS/CSS in app/assets folder are already added.
+Rails.application.config.assets.precompile += %w( email.css )
diff --git a/spec/railsapps/rails_52/config/initializers/backtrace_silencers.rb b/spec/railsapps/rails_52/config/initializers/backtrace_silencers.rb
new file mode 100644
index 0000000..59385cd
--- /dev/null
+++ b/spec/railsapps/rails_52/config/initializers/backtrace_silencers.rb
@@ -0,0 +1,7 @@
+# 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.
+# Rails.backtrace_cleaner.add_silencer { |line| line =~ /my_noisy_library/ }
+
+# You can also remove all the silencers if you're trying to debug a problem that might stem from framework code.
+# Rails.backtrace_cleaner.remove_silencers!
diff --git a/spec/railsapps/rails_52/config/initializers/cookies_serializer.rb b/spec/railsapps/rails_52/config/initializers/cookies_serializer.rb
new file mode 100644
index 0000000..5a6a32d
--- /dev/null
+++ b/spec/railsapps/rails_52/config/initializers/cookies_serializer.rb
@@ -0,0 +1,5 @@
+# Be sure to restart your server when you modify this file.
+
+# Specify a serializer for the signed and encrypted cookie jars.
+# Valid options are :json, :marshal, and :hybrid.
+Rails.application.config.action_dispatch.cookies_serializer = :json
diff --git a/spec/railsapps/rails_52/config/initializers/filter_parameter_logging.rb b/spec/railsapps/rails_52/config/initializers/filter_parameter_logging.rb
new file mode 100644
index 0000000..4a994e1
--- /dev/null
+++ b/spec/railsapps/rails_52/config/initializers/filter_parameter_logging.rb
@@ -0,0 +1,4 @@
+# Be sure to restart your server when you modify this file.
+
+# Configure sensitive parameters which will be filtered from the log file.
+Rails.application.config.filter_parameters += [:password]
diff --git a/spec/railsapps/rails_52/config/initializers/inflections.rb b/spec/railsapps/rails_52/config/initializers/inflections.rb
new file mode 100644
index 0000000..ac033bf
--- /dev/null
+++ b/spec/railsapps/rails_52/config/initializers/inflections.rb
@@ -0,0 +1,16 @@
+# Be sure to restart your server when you modify this file.
+
+# Add new inflection rules using the following format. Inflections
+# are locale specific, and you may define rules for as many different
+# locales as you wish. All of these examples are active by default:
+# ActiveSupport::Inflector.inflections(:en) do |inflect|
+#   inflect.plural /^(ox)$/i, '\1en'
+#   inflect.singular /^(ox)en/i, '\1'
+#   inflect.irregular 'person', 'people'
+#   inflect.uncountable %w( fish sheep )
+# end
+
+# These inflection rules are supported but not enabled by default:
+# ActiveSupport::Inflector.inflections(:en) do |inflect|
+#   inflect.acronym 'RESTful'
+# end
diff --git a/spec/railsapps/rails_52/config/initializers/mime_types.rb b/spec/railsapps/rails_52/config/initializers/mime_types.rb
new file mode 100644
index 0000000..dc18996
--- /dev/null
+++ b/spec/railsapps/rails_52/config/initializers/mime_types.rb
@@ -0,0 +1,4 @@
+# Be sure to restart your server when you modify this file.
+
+# Add new mime types for use in respond_to blocks:
+# Mime::Type.register "text/richtext", :rtf
diff --git a/spec/railsapps/rails_52/config/initializers/new_framework_defaults.rb b/spec/railsapps/rails_52/config/initializers/new_framework_defaults.rb
new file mode 100644
index 0000000..0859f91
--- /dev/null
+++ b/spec/railsapps/rails_52/config/initializers/new_framework_defaults.rb
@@ -0,0 +1,18 @@
+# Be sure to restart your server when you modify this file.
+#
+# This file contains migration options to ease your Rails 5.0 upgrade.
+#
+# Read the Guide for Upgrading Ruby on Rails for more info on each option.
+
+# Enable per-form CSRF tokens. Previous versions had false.
+Rails.application.config.action_controller.per_form_csrf_tokens = true
+
+# Enable origin-checking CSRF mitigation. Previous versions had false.
+Rails.application.config.action_controller.forgery_protection_origin_check = true
+
+# Make Ruby 2.4 preserve the timezone of the receiver when calling `to_time`.
+# Previous versions had false.
+ActiveSupport.to_time_preserves_timezone = true
+
+# Configure SSL options to enable HSTS with subdomains. Previous versions had false.
+Rails.application.config.ssl_options = { hsts: { subdomains: true } }
diff --git a/spec/railsapps/rails_52/config/initializers/session_store.rb b/spec/railsapps/rails_52/config/initializers/session_store.rb
new file mode 100644
index 0000000..e26c847
--- /dev/null
+++ b/spec/railsapps/rails_52/config/initializers/session_store.rb
@@ -0,0 +1,3 @@
+# Be sure to restart your server when you modify this file.
+
+Rails.application.config.session_store :cookie_store, key: '_rails_51_session'
diff --git a/spec/railsapps/rails_52/config/initializers/wrap_parameters.rb b/spec/railsapps/rails_52/config/initializers/wrap_parameters.rb
new file mode 100644
index 0000000..633c1c8
--- /dev/null
+++ b/spec/railsapps/rails_52/config/initializers/wrap_parameters.rb
@@ -0,0 +1,9 @@
+# Be sure to restart your server when you modify this file.
+
+# This file contains settings for ActionController::ParamsWrapper which
+# is enabled by default.
+
+# Enable parameter wrapping for JSON. You can disable this by setting :format to an empty array.
+ActiveSupport.on_load(:action_controller) do
+  wrap_parameters format: [:json]
+end
diff --git a/spec/railsapps/rails_52/config/locales/en.yml b/spec/railsapps/rails_52/config/locales/en.yml
new file mode 100644
index 0000000..0653957
--- /dev/null
+++ b/spec/railsapps/rails_52/config/locales/en.yml
@@ -0,0 +1,23 @@
+# Files in the config/locales directory are used for internationalization
+# and are automatically loaded by Rails. If you want to use locales other
+# than English, add the necessary files in this directory.
+#
+# To use the locales, use `I18n.t`:
+#
+#     I18n.t 'hello'
+#
+# In views, this is aliased to just `t`:
+#
+#     <%= t('hello') %>
+#
+# To use a different locale, set it with `I18n.locale`:
+#
+#     I18n.locale = :es
+#
+# This would use the information in config/locales/es.yml.
+#
+# To learn more, please read the Rails Internationalization guide
+# available at http://guides.rubyonrails.org/i18n.html.
+
+en:
+  hello: "Hello world"
diff --git a/spec/railsapps/rails_52/config/routes.rb b/spec/railsapps/rails_52/config/routes.rb
new file mode 100644
index 0000000..787824f
--- /dev/null
+++ b/spec/railsapps/rails_52/config/routes.rb
@@ -0,0 +1,3 @@
+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/spec/railsapps/rails_52/log/.keep b/spec/railsapps/rails_52/log/.keep
new file mode 100644
index 0000000..e69de29
diff --git a/spec/railsapps/rails_master/.gitignore b/spec/railsapps/rails_master/.gitignore
new file mode 100644
index 0000000..48fb168
--- /dev/null
+++ b/spec/railsapps/rails_master/.gitignore
@@ -0,0 +1,17 @@
+# See https://help.github.com/articles/ignoring-files for more about ignoring files.
+#
+# If you find yourself ignoring temporary files generated by your text editor
+# or operating system, you probably want to add a global ignore instead:
+#   git config --global core.excludesfile '~/.gitignore_global'
+
+# Ignore bundler config.
+/.bundle
+
+# Ignore all logfiles and tempfiles.
+/log/*
+/tmp/*
+!/log/.keep
+!/tmp/.keep
+
+# Ignore Byebug command history file.
+.byebug_history
diff --git a/spec/railsapps/rails_master/Gemfile b/spec/railsapps/rails_master/Gemfile
new file mode 100644
index 0000000..847eca5
--- /dev/null
+++ b/spec/railsapps/rails_master/Gemfile
@@ -0,0 +1,10 @@
+source 'https://rubygems.org'
+
+git_source(:github) { |repo| "https://github.com/#{repo}.git" }
+
+gem 'rails', github: 'rails/rails'
+gem 'sass-rails'
+gem 'sprockets-rails'
+gem 'listen'
+
+gem 'roadie-rails', path: '../../..'
diff --git a/spec/railsapps/rails_master/app/assets/images/rails.png b/spec/railsapps/rails_master/app/assets/images/rails.png
new file mode 100644
index 0000000..d5edc04
Binary files /dev/null and b/spec/railsapps/rails_master/app/assets/images/rails.png differ
diff --git a/spec/railsapps/rails_master/app/assets/stylesheets/email.css.scss b/spec/railsapps/rails_master/app/assets/stylesheets/email.css.scss
new file mode 100644
index 0000000..8fb351f
--- /dev/null
+++ b/spec/railsapps/rails_master/app/assets/stylesheets/email.css.scss
@@ -0,0 +1,2 @@
+body { background-color: green; }
+.image { background: image-url("rails.png"); }
diff --git a/spec/railsapps/rails_master/app/mailers/auto_mailer.rb b/spec/railsapps/rails_master/app/mailers/auto_mailer.rb
new file mode 100644
index 0000000..81f522e
--- /dev/null
+++ b/spec/railsapps/rails_master/app/mailers/auto_mailer.rb
@@ -0,0 +1,27 @@
+class AutoMailer < ActionMailer::Base
+  include Roadie::Rails::Automatic
+
+  default from: 'john@example.com'
+
+  def normal_email
+    generate_email
+  end
+
+  def disabled_email
+    generate_email
+  end
+
+  private
+  def roadie_options
+    unless action_name =~ /disabled/
+      super.combine(url_options: {protocol: "https"})
+    end
+  end
+
+  def generate_email
+    mail(to: 'example@example.org', subject: "Notification for you") do |format|
+      format.html { render :normal_email }
+      format.text { render :normal_email }
+    end
+  end
+end
diff --git a/spec/railsapps/rails_master/app/mailers/mailer.rb b/spec/railsapps/rails_master/app/mailers/mailer.rb
new file mode 100644
index 0000000..87cbb8a
--- /dev/null
+++ b/spec/railsapps/rails_master/app/mailers/mailer.rb
@@ -0,0 +1,17 @@
+class Mailer < ActionMailer::Base
+  include Roadie::Rails::Mailer
+
+  default from: 'john@example.com'
+
+  def normal_email
+    roadie_mail(to: 'example@example.org', subject: "Notification for you") do |format|
+      format.html
+      format.text
+    end
+  end
+
+  private
+  def roadie_options
+    super.combine(url_options: {protocol: "https"})
+  end
+end
diff --git a/spec/railsapps/rails_master/app/views/auto_mailer/normal_email.html.erb b/spec/railsapps/rails_master/app/views/auto_mailer/normal_email.html.erb
new file mode 100644
index 0000000..cf672b4
--- /dev/null
+++ b/spec/railsapps/rails_master/app/views/auto_mailer/normal_email.html.erb
@@ -0,0 +1,11 @@
+<!DOCTYPE html>
+<html>
+  <head>
+    <meta http-equiv="content-type" content="text/html; charset=utf-8">
+    <%= stylesheet_link_tag "email" %>
+  </head>
+  <body>
+    <h1>Normal email</h1>
+    <div class="image"></div>
+  </body>
+</html>
diff --git a/spec/railsapps/rails_master/app/views/auto_mailer/normal_email.text b/spec/railsapps/rails_master/app/views/auto_mailer/normal_email.text
new file mode 100644
index 0000000..302fdf4
--- /dev/null
+++ b/spec/railsapps/rails_master/app/views/auto_mailer/normal_email.text
@@ -0,0 +1 @@
+Normal email
diff --git a/spec/railsapps/rails_master/app/views/mailer/normal_email.html.erb b/spec/railsapps/rails_master/app/views/mailer/normal_email.html.erb
new file mode 100644
index 0000000..cf672b4
--- /dev/null
+++ b/spec/railsapps/rails_master/app/views/mailer/normal_email.html.erb
@@ -0,0 +1,11 @@
+<!DOCTYPE html>
+<html>
+  <head>
+    <meta http-equiv="content-type" content="text/html; charset=utf-8">
+    <%= stylesheet_link_tag "email" %>
+  </head>
+  <body>
+    <h1>Normal email</h1>
+    <div class="image"></div>
+  </body>
+</html>
diff --git a/spec/railsapps/rails_master/app/views/mailer/normal_email.text b/spec/railsapps/rails_master/app/views/mailer/normal_email.text
new file mode 100644
index 0000000..302fdf4
--- /dev/null
+++ b/spec/railsapps/rails_master/app/views/mailer/normal_email.text
@@ -0,0 +1 @@
+Normal email
diff --git a/spec/railsapps/rails_master/bin/rails b/spec/railsapps/rails_master/bin/rails
new file mode 100755
index 0000000..5191e69
--- /dev/null
+++ b/spec/railsapps/rails_master/bin/rails
@@ -0,0 +1,4 @@
+#!/usr/bin/env ruby
+APP_PATH = File.expand_path('../../config/application', __FILE__)
+require_relative '../config/boot'
+require 'rails/commands'
diff --git a/spec/railsapps/rails_master/config.ru b/spec/railsapps/rails_master/config.ru
new file mode 100644
index 0000000..f7ba0b5
--- /dev/null
+++ b/spec/railsapps/rails_master/config.ru
@@ -0,0 +1,5 @@
+# This file is used by Rack-based servers to start the application.
+
+require_relative 'config/environment'
+
+run Rails.application
diff --git a/spec/railsapps/rails_master/config/application.rb b/spec/railsapps/rails_master/config/application.rb
new file mode 100644
index 0000000..693e685
--- /dev/null
+++ b/spec/railsapps/rails_master/config/application.rb
@@ -0,0 +1,16 @@
+require_relative 'boot'
+
+require 'action_controller/railtie'
+require 'action_mailer/railtie'
+require 'action_view/railtie'
+require 'sprockets/railtie'
+
+# Require the gems listed in Gemfile, including any gems
+# you've limited to :test, :development, or :production.
+Bundler.require(*Rails.groups)
+
+module RailsMaster
+  class Application < Rails::Application
+    config.roadie.url_options = { host: 'example.app.org' }
+  end
+end
diff --git a/spec/railsapps/rails_master/config/boot.rb b/spec/railsapps/rails_master/config/boot.rb
new file mode 100644
index 0000000..30f5120
--- /dev/null
+++ b/spec/railsapps/rails_master/config/boot.rb
@@ -0,0 +1,3 @@
+ENV['BUNDLE_GEMFILE'] ||= File.expand_path('../Gemfile', __dir__)
+
+require 'bundler/setup' # Set up gems listed in the Gemfile.
diff --git a/spec/railsapps/rails_master/config/environment.rb b/spec/railsapps/rails_master/config/environment.rb
new file mode 100644
index 0000000..426333b
--- /dev/null
+++ b/spec/railsapps/rails_master/config/environment.rb
@@ -0,0 +1,5 @@
+# Load the Rails application.
+require_relative 'application'
+
+# Initialize the Rails application.
+Rails.application.initialize!
diff --git a/spec/railsapps/rails_master/config/environments/development.rb b/spec/railsapps/rails_master/config/environments/development.rb
new file mode 100644
index 0000000..58d20de
--- /dev/null
+++ b/spec/railsapps/rails_master/config/environments/development.rb
@@ -0,0 +1,51 @@
+Rails.application.configure do
+  # Settings specified here will take precedence over those in config/application.rb.
+
+  # In the development environment your application's code is reloaded on
+  # every request. This slows down response time but is perfect for development
+  # since you don't have to restart the web server when you make code changes.
+  config.cache_classes = false
+
+  # Do not eager load code on boot.
+  config.eager_load = false
+
+  # Show full error reports.
+  config.consider_all_requests_local = true
+
+  # Enable/disable caching. By default caching is disabled.
+  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=172800'
+    }
+  else
+    config.action_controller.perform_caching = false
+
+    config.cache_store = :null_store
+  end
+
+  # Don't care if the mailer can't send.
+  config.action_mailer.raise_delivery_errors = false
+
+  config.action_mailer.perform_caching = false
+
+  # Print deprecation notices to the Rails logger.
+  config.active_support.deprecation = :log
+
+  # Debug mode disables concatenation and preprocessing of assets.
+  # This option may cause significant delays in view rendering with a large
+  # number of complex assets.
+  config.assets.debug = true
+
+  # Suppress logger output for asset requests.
+  config.assets.quiet = true
+
+  # Raises error for missing translations
+  # config.action_view.raise_on_missing_translations = true
+
+  # Use an evented file watcher to asynchronously detect changes in source code,
+  # routes, locales, etc. This feature depends on the listen gem.
+  config.file_watcher = ActiveSupport::EventedFileUpdateChecker
+end
diff --git a/spec/railsapps/rails_master/config/environments/production.rb b/spec/railsapps/rails_master/config/environments/production.rb
new file mode 100644
index 0000000..7dabce6
--- /dev/null
+++ b/spec/railsapps/rails_master/config/environments/production.rb
@@ -0,0 +1,83 @@
+Rails.application.configure do
+  # Settings specified here will take precedence over those in config/application.rb.
+
+  # Code is not reloaded between requests.
+  config.cache_classes = true
+
+  # Eager load code on boot. This eager loads most of Rails and
+  # your application in memory, allowing both threaded web servers
+  # and those relying on copy on write to perform better.
+  # Rake tasks automatically ignore this option for performance.
+  config.eager_load = true
+
+  # Full error reports are disabled and caching is turned on.
+  config.consider_all_requests_local       = false
+  config.action_controller.perform_caching = true
+
+  # 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?
+
+  # Compress JavaScripts and CSS.
+  config.assets.js_compressor = :uglifier
+  # config.assets.css_compressor = :sass
+
+  # Do not fallback to assets pipeline if a precompiled asset is missed.
+  config.assets.compile = false
+
+  # `config.assets.precompile` and `config.assets.version` have moved to config/initializers/assets.rb
+
+  # Enable serving of images, stylesheets, and JavaScripts from an asset server.
+  # config.action_controller.asset_host = 'http://assets.example.com'
+
+  # Specifies the header that your server uses for sending files.
+  # config.action_dispatch.x_sendfile_header = 'X-Sendfile' # for Apache
+  # config.action_dispatch.x_sendfile_header = 'X-Accel-Redirect' # for NGINX
+
+  # Mount Action Cable outside main process or domain
+  # config.action_cable.mount_path = nil
+  # config.action_cable.url = 'wss://example.com/cable'
+  # config.action_cable.allowed_request_origins = [ 'http://example.com', /http:\/\/example.*/ ]
+
+  # Force all access to the app over SSL, use Strict-Transport-Security, and use secure cookies.
+  # config.force_ssl = true
+
+  # Use the lowest log level to ensure availability of diagnostic information
+  # when problems arise.
+  config.log_level = :debug
+
+  # Prepend all log lines with the following tags.
+  config.log_tags = [ :request_id ]
+
+  # Use a different cache store in production.
+  # config.cache_store = :mem_cache_store
+
+  # Use a real queuing backend for Active Job (and separate queues per environment)
+  # config.active_job.queue_adapter     = :resque
+  # config.active_job.queue_name_prefix = "rails_51_#{Rails.env}"
+  config.action_mailer.perform_caching = false
+
+  # Ignore bad email addresses and do not raise email delivery errors.
+  # Set this to true and configure the email server for immediate delivery to raise delivery errors.
+  # config.action_mailer.raise_delivery_errors = false
+
+  # Enable locale fallbacks for I18n (makes lookups for any locale fall back to
+  # the I18n.default_locale when a translation cannot be found).
+  config.i18n.fallbacks = true
+
+  # Send deprecation notices to registered listeners.
+  config.active_support.deprecation = :notify
+
+  # Use default logging formatter so that PID and timestamp are not suppressed.
+  config.log_formatter = ::Logger::Formatter.new
+
+  # Use a different logger for distributed setups.
+  # require 'syslog/logger'
+  # config.logger = ActiveSupport::TaggedLogging.new(Syslog::Logger.new 'app-name')
+
+  if ENV["RAILS_LOG_TO_STDOUT"].present?
+    logger           = ActiveSupport::Logger.new(STDOUT)
+    logger.formatter = config.log_formatter
+    config.logger = ActiveSupport::TaggedLogging.new(logger)
+  end
+end
diff --git a/spec/railsapps/rails_master/config/environments/test.rb b/spec/railsapps/rails_master/config/environments/test.rb
new file mode 100644
index 0000000..30587ef
--- /dev/null
+++ b/spec/railsapps/rails_master/config/environments/test.rb
@@ -0,0 +1,42 @@
+Rails.application.configure do
+  # Settings specified here will take precedence over those in config/application.rb.
+
+  # The test environment is used exclusively to run your application's
+  # test suite. You never need to work with it otherwise. Remember that
+  # your test database is "scratch space" for the test suite and is wiped
+  # and recreated between test runs. Don't rely on the data there!
+  config.cache_classes = true
+
+  # Do not eager load code on boot. This avoids loading your whole application
+  # just for the purpose of running a single test. If you are using a tool that
+  # preloads Rails for running tests, you may have to set it to true.
+  config.eager_load = false
+
+  # 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=3600'
+  }
+
+  # Show full error reports and disable caching.
+  config.consider_all_requests_local       = true
+  config.action_controller.perform_caching = false
+
+  # Raise exceptions instead of rendering exception templates.
+  config.action_dispatch.show_exceptions = false
+
+  # Disable request forgery protection in test environment.
+  config.action_controller.allow_forgery_protection = false
+  config.action_mailer.perform_caching = false
+
+  # Tell Action Mailer not to deliver emails to the real world.
+  # The :test delivery method accumulates sent emails in the
+  # ActionMailer::Base.deliveries array.
+  config.action_mailer.delivery_method = :test
+
+  # Print deprecation notices to the stderr.
+  config.active_support.deprecation = :stderr
+
+  # Raises error for missing translations
+  # config.action_view.raise_on_missing_translations = true
+end
diff --git a/spec/railsapps/rails_master/config/initializers/application_controller_renderer.rb b/spec/railsapps/rails_master/config/initializers/application_controller_renderer.rb
new file mode 100644
index 0000000..51639b6
--- /dev/null
+++ b/spec/railsapps/rails_master/config/initializers/application_controller_renderer.rb
@@ -0,0 +1,6 @@
+# Be sure to restart your server when you modify this file.
+
+# ApplicationController.renderer.defaults.merge!(
+#   http_host: 'example.org',
+#   https: false
+# )
diff --git a/spec/railsapps/rails_master/config/initializers/assets.rb b/spec/railsapps/rails_master/config/initializers/assets.rb
new file mode 100644
index 0000000..8bf3ad0
--- /dev/null
+++ b/spec/railsapps/rails_master/config/initializers/assets.rb
@@ -0,0 +1,11 @@
+# Be sure to restart your server when you modify this file.
+
+# Version of your assets, change this if you want to expire all your assets.
+Rails.application.config.assets.version = '1.0'
+
+# Add additional assets to the asset load path
+# Rails.application.config.assets.paths << Emoji.images_path
+
+# Precompile additional assets.
+# application.js, application.css, and all non-JS/CSS in app/assets folder are already added.
+Rails.application.config.assets.precompile += %w( email.css )
diff --git a/spec/railsapps/rails_master/config/initializers/backtrace_silencers.rb b/spec/railsapps/rails_master/config/initializers/backtrace_silencers.rb
new file mode 100644
index 0000000..59385cd
--- /dev/null
+++ b/spec/railsapps/rails_master/config/initializers/backtrace_silencers.rb
@@ -0,0 +1,7 @@
+# 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.
+# Rails.backtrace_cleaner.add_silencer { |line| line =~ /my_noisy_library/ }
+
+# You can also remove all the silencers if you're trying to debug a problem that might stem from framework code.
+# Rails.backtrace_cleaner.remove_silencers!
diff --git a/spec/railsapps/rails_master/config/initializers/cookies_serializer.rb b/spec/railsapps/rails_master/config/initializers/cookies_serializer.rb
new file mode 100644
index 0000000..5a6a32d
--- /dev/null
+++ b/spec/railsapps/rails_master/config/initializers/cookies_serializer.rb
@@ -0,0 +1,5 @@
+# Be sure to restart your server when you modify this file.
+
+# Specify a serializer for the signed and encrypted cookie jars.
+# Valid options are :json, :marshal, and :hybrid.
+Rails.application.config.action_dispatch.cookies_serializer = :json
diff --git a/spec/railsapps/rails_master/config/initializers/filter_parameter_logging.rb b/spec/railsapps/rails_master/config/initializers/filter_parameter_logging.rb
new file mode 100644
index 0000000..4a994e1
--- /dev/null
+++ b/spec/railsapps/rails_master/config/initializers/filter_parameter_logging.rb
@@ -0,0 +1,4 @@
+# Be sure to restart your server when you modify this file.
+
+# Configure sensitive parameters which will be filtered from the log file.
+Rails.application.config.filter_parameters += [:password]
diff --git a/spec/railsapps/rails_master/config/initializers/inflections.rb b/spec/railsapps/rails_master/config/initializers/inflections.rb
new file mode 100644
index 0000000..ac033bf
--- /dev/null
+++ b/spec/railsapps/rails_master/config/initializers/inflections.rb
@@ -0,0 +1,16 @@
+# Be sure to restart your server when you modify this file.
+
+# Add new inflection rules using the following format. Inflections
+# are locale specific, and you may define rules for as many different
+# locales as you wish. All of these examples are active by default:
+# ActiveSupport::Inflector.inflections(:en) do |inflect|
+#   inflect.plural /^(ox)$/i, '\1en'
+#   inflect.singular /^(ox)en/i, '\1'
+#   inflect.irregular 'person', 'people'
+#   inflect.uncountable %w( fish sheep )
+# end
+
+# These inflection rules are supported but not enabled by default:
+# ActiveSupport::Inflector.inflections(:en) do |inflect|
+#   inflect.acronym 'RESTful'
+# end
diff --git a/spec/railsapps/rails_master/config/initializers/mime_types.rb b/spec/railsapps/rails_master/config/initializers/mime_types.rb
new file mode 100644
index 0000000..dc18996
--- /dev/null
+++ b/spec/railsapps/rails_master/config/initializers/mime_types.rb
@@ -0,0 +1,4 @@
+# Be sure to restart your server when you modify this file.
+
+# Add new mime types for use in respond_to blocks:
+# Mime::Type.register "text/richtext", :rtf
diff --git a/spec/railsapps/rails_master/config/initializers/new_framework_defaults.rb b/spec/railsapps/rails_master/config/initializers/new_framework_defaults.rb
new file mode 100644
index 0000000..0859f91
--- /dev/null
+++ b/spec/railsapps/rails_master/config/initializers/new_framework_defaults.rb
@@ -0,0 +1,18 @@
+# Be sure to restart your server when you modify this file.
+#
+# This file contains migration options to ease your Rails 5.0 upgrade.
+#
+# Read the Guide for Upgrading Ruby on Rails for more info on each option.
+
+# Enable per-form CSRF tokens. Previous versions had false.
+Rails.application.config.action_controller.per_form_csrf_tokens = true
+
+# Enable origin-checking CSRF mitigation. Previous versions had false.
+Rails.application.config.action_controller.forgery_protection_origin_check = true
+
+# Make Ruby 2.4 preserve the timezone of the receiver when calling `to_time`.
+# Previous versions had false.
+ActiveSupport.to_time_preserves_timezone = true
+
+# Configure SSL options to enable HSTS with subdomains. Previous versions had false.
+Rails.application.config.ssl_options = { hsts: { subdomains: true } }
diff --git a/spec/railsapps/rails_master/config/initializers/session_store.rb b/spec/railsapps/rails_master/config/initializers/session_store.rb
new file mode 100644
index 0000000..e26c847
--- /dev/null
+++ b/spec/railsapps/rails_master/config/initializers/session_store.rb
@@ -0,0 +1,3 @@
+# Be sure to restart your server when you modify this file.
+
+Rails.application.config.session_store :cookie_store, key: '_rails_51_session'
diff --git a/spec/railsapps/rails_master/config/initializers/wrap_parameters.rb b/spec/railsapps/rails_master/config/initializers/wrap_parameters.rb
new file mode 100644
index 0000000..633c1c8
--- /dev/null
+++ b/spec/railsapps/rails_master/config/initializers/wrap_parameters.rb
@@ -0,0 +1,9 @@
+# Be sure to restart your server when you modify this file.
+
+# This file contains settings for ActionController::ParamsWrapper which
+# is enabled by default.
+
+# Enable parameter wrapping for JSON. You can disable this by setting :format to an empty array.
+ActiveSupport.on_load(:action_controller) do
+  wrap_parameters format: [:json]
+end
diff --git a/spec/railsapps/rails_master/config/locales/en.yml b/spec/railsapps/rails_master/config/locales/en.yml
new file mode 100644
index 0000000..0653957
--- /dev/null
+++ b/spec/railsapps/rails_master/config/locales/en.yml
@@ -0,0 +1,23 @@
+# Files in the config/locales directory are used for internationalization
+# and are automatically loaded by Rails. If you want to use locales other
+# than English, add the necessary files in this directory.
+#
+# To use the locales, use `I18n.t`:
+#
+#     I18n.t 'hello'
+#
+# In views, this is aliased to just `t`:
+#
+#     <%= t('hello') %>
+#
+# To use a different locale, set it with `I18n.locale`:
+#
+#     I18n.locale = :es
+#
+# This would use the information in config/locales/es.yml.
+#
+# To learn more, please read the Rails Internationalization guide
+# available at http://guides.rubyonrails.org/i18n.html.
+
+en:
+  hello: "Hello world"
diff --git a/spec/railsapps/rails_master/config/routes.rb b/spec/railsapps/rails_master/config/routes.rb
new file mode 100644
index 0000000..787824f
--- /dev/null
+++ b/spec/railsapps/rails_master/config/routes.rb
@@ -0,0 +1,3 @@
+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/spec/railsapps/rails_master/log/.keep b/spec/railsapps/rails_master/log/.keep
new file mode 100644
index 0000000..e69de29
diff --git a/spec/support/rails_app.rb b/spec/support/rails_app.rb
index 08dbe4d..fdd08d8 100644
--- a/spec/support/rails_app.rb
+++ b/spec/support/rails_app.rb
@@ -1,7 +1,9 @@
 class RailsApp
+  attr_reader :name, :path
+
   def initialize(name, path, options = {})
-    @name = name
-    @path = File.expand_path("../../railsapps/#{path}", __FILE__)
+    @name, @path = name, path
+    @full_path = File.expand_path("../../railsapps/#{path}", __FILE__)
     @runner = options.fetch(:runner)
     @using_asset_pipeline = options.fetch(:asset_pipeline)
     @digests = options.fetch(:digests)
@@ -61,7 +63,7 @@ def run_file_in_app_context(file_path)
 
   def run_in_app_context(command)
     Bundler.with_clean_env do
-      Dir.chdir @path do
+      Dir.chdir @full_path do
         IO.popen(command).read
       end
     end