Rails: output deprecation warnings

Question

What kind of deprecation warnings should we expect from Rails?

About to upgrade from Rails 4.1 -> 4.2 and I'm looking in the terminal and the development.log for deprecation warnings and not seeing any. Either I'm looking in the wrong places...or I don't have any.

However, I do have an instance of File.exists? in this codebase and I know that is (was?) deprecated in favor of File.exist?. Will Rails flag this for me somewhere, as some other frameworks do, or do I need to uncover/discover these issues myself?

Answer 1

Rails will log deprecations - how this is done is controlled by the config.active_support.deprecation setting (:log, :stderr, :raise, :silence or :notify)

File.exist? is a ruby method though and so is not affected by this setting. Ruby will emit a warning if you use this method, although you will need to run ruby with warnings enabled to see them.