Fork of @ericboehs Poltergeist hack to silence CoreText performance notes from phantomjs My changes: 1. to is now optional parameter, if not provided @write_io is used 2. option to easily add more messages to suppress (I added this one WARNING: Method userSpaceScaleFactor in class NSView is deprecated)

gistfile1.rb

module Capybara::Poltergeist
  class Client
    private
    def redirect_stdout(to = nil)
      to ||= @write_io
      prev = STDOUT.dup
      prev.autoclose = false
      $stdout = to
      STDOUT.reopen(to)

      prev = STDERR.dup
      prev.autoclose = false
      $stderr = to
      STDERR.reopen(to)
      yield
    ensure
      STDOUT.reopen(prev)
      $stdout = STDOUT
      STDERR.reopen(prev)
      $stderr = STDERR
    end
  end
end

class WarningSuppressor
  class << self
    def write(message)
      if message_to_supress?(message) 
        0 
      else 
        puts(message)
        1
      end
    end

    private

    def message_to_supress?(message)
      messages = [
        "QFont::setPixelSize: Pixel size <= 0",
        "CoreText performance note",
        "WARNING: Method userSpaceScaleFactor in class NSView is deprecated"
      ]  
     messsage =~ Regexp.compile("(#{messages.join('|')})")
    end
  end
end

Capybara.register_driver :poltergeist do |app|
  Capybara::Poltergeist::Driver.new(app, phantomjs_logger: WarningSuppressor)
end

Capybara.javascript_driver = :poltergeist