Poltergeist hack to silence CoreText performance notes from phantomjs

gistfile1.rb

module Capybara::Poltergeist
  class Client
    private
    def redirect_stdout(to)
      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 =~ /QFont::setPixelSize: Pixel size <= 0/ || message =~/CoreText performance note:/ then 0 else puts(message);1;end
    end
  end
end

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

Capybara.javascript_driver = :poltergeist

wrong number of arguments (0 for 1)
# ./spec/support/monkeypatch_mavericks.rb:4:in `redirect_stdout'

any ideas? ruby 2.0.0-p247, rails 3.2.15

I'll rtfm in the meantime :)

Same thing here. ruby 2.0.0-p195, rails 4.0.0

This worked for me

def redirect_stdout
  prev = STDOUT.dup
  prev.autoclose = false
  $stdout = @write_io
  STDOUT.reopen(@write_io)

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

Thanks! It works!

Thanks @matheusbras 👍

Thanks @matheusbras.

Can anyone give little help on what I'd need to change to apply this to the :poltergeist_billy driver? Not a ruby developer but using Cappy in our test suite.

@robwierzbowski here is the fix for billy.

Thanks for sharing this gist! Works for me.

Thanks!

@ericboehs Now a really dumb question: Isn't prevoverwriting each other?

Extending this pattern for other unwanted output:

class WarningSuppressor
  IGNORES = [
    /QFont::setPixelSize: Pixel size <= 0/,
    /CoreText performance note:/,
    /Heya! This page is using wysihtml5/
  ]

  class << self
    def write(message)
      if suppress?(message) then 0 else puts(message);1;end
    end

    private

    def suppress?(message)
      IGNORES.any? { |re| message =~ re }
    end
  end
end

I had trouble making this cooperate with a phantomjs installed by phantomjs-gem. I straightened it out by changing the way the Driver's initialized:

require 'phantomjs'

#...everything as described above...

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

Just noting this for anyone who comes along with the same problem :~)

I created a gem: https://github.com/uiureo/poltergeist-suppressor

You can write like this:

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