In Rails 4.2, you can define your own application specific custom variables in development.rb, test.rb and so on. If you define this:
config.x.whatever.value.want = 42
It throws the error : undefined method `want=' for nil:NilClass (NoMethodError)
It seems to work only for two levels, so, this will work:
config.x.whatever.value = 42
You can access the value like this:
Rails.configuration.x.whatever.value
You need to define the custom values by using 'config.x'.
