Run Ruby with warnings enabled. Without going crazy.

warning_filter.rb

require 'delegate'

module Support
  class WarningFilter < DelegateClass(IO)
    def write(line)
      super if line !~ /^\S+gems\/ruby\-\S+:\d+: warning:/
    end
  end
end

$stderr = Support::WarningFilter.new($stderr)

Thanks for sharing! )

Am I doing something wrong?

$:> irb
>> RUBY_VERSION
=> "2.1.0"
>> require_relative 'test/warning_filter.rb'
=> true
>> Dir.exists? 'dir'
=> false

$:> irb -w
>> Dir.exists? 'dir'
(irb):1: warning: Dir.exists? is a deprecated name, use Dir.exist? instead
=> false

Ah, no, it's not supposed to filter out these warnings. It's only supposed to filter out warnings coming from third-party gems. Note that you didn't run with -w in the first example.

THANK YOU!