```ruby
Rails.env = ENV['RAILS_ENV'] || 'test'

module Combustion
  class Application < Rails::Application
    # Core Settings
    config.cache_classes               = true
    config.whiny_nils                  = true
    config.consider_all_requests_local = true
    config.secret_token                = Digest::SHA1.hexdigest Time.now.to_s

    # ActiveSupport Settings
    config.active_support.deprecation = :stderr

    # Turn on ActiveRecord attribute whitelisting
    # This way the dummy app matches new rails apps re: this setting
    config.active_record.whitelist_attributes = true if config.respond_to? :active_record

    # Some settings we're not sure if we want, so let's not load them by default.
    # Instead, wait for this method to be invoked (to get around load-order
    # complications).
    def self.configure_for_combustion
      config.root = File.expand_path File.join(Dir.pwd, Combustion.path)

      if defined? ActionController::Railtie
        config.action_dispatch.show_exceptions            = false
        config.action_controller.perform_caching          = false
        config.action_controller.allow_forgery_protection = false
      end

      if defined? ActionMailer::Railtie
        config.action_mailer.delivery_method     = :test
        config.action_mailer.default_url_options = {:host => 'www.example.com'}
      end

      if defined? Sprockets
        config.assets.enabled = true
      end
    end
  end
end
```

Disable setting whiny_nils when using Rails 4.0.0 and later.
user
```ruby
Rails.env = ENV['RAILS_ENV'] || 'test'

module Combustion
  class Application < Rails::Application
    # Core Settings
    config.cache_classes               = true
    config.whiny_nils                  = true if Rails.version < '4.0.0'
    config.consider_all_requests_local = true
    config.secret_token                = Digest::SHA1.hexdigest Time.now.to_s

    # ActiveSupport Settings
    config.active_support.deprecation = :stderr

    # Turn on ActiveRecord attribute whitelisting
    # This way the dummy app matches new rails apps re: this setting
    config.active_record.whitelist_attributes = true if config.respond_to? :active_record

    # Some settings we're not sure if we want, so let's not load them by default.
    # Instead, wait for this method to be invoked (to get around load-order
    # complications).
    def self.configure_for_combustion
      config.root = File.expand_path File.join(Dir.pwd, Combustion.path)

      if defined? ActionController::Railtie
        config.action_dispatch.show_exceptions            = false
        config.action_controller.perform_caching          = false
        config.action_controller.allow_forgery_protection = false
      end

      if defined? ActionMailer::Railtie
        config.action_mailer.delivery_method     = :test
        config.action_mailer.default_url_options = {:host => 'www.example.com'}
      end

      if defined? Sprockets
        config.assets.enabled = true
      end
    end
  end
end
```
assistant