Get all the logging and exceptions from your Capybara-driven Rails app in your Cucumber environment

gistfile1.rb

# come here mr. ducky, i just want to punch you
module Capybara
  class << self
    def logger_target
      @logger_target ||= StringIO.new
    end

    attr_writer :backtrace_clean_patterns

    def backtrace_clean_patterns
      @backtrace_clean_patterns ||= [ %r{/gems/}, %r{/ruby/1} ]
    end
  end
end

Rails.logger = Logger.new(Capybara.logger_target)

Capybara.server do |app, port|
  require 'rack/handler/webrick'

  logger = Logger.new(Capybara.logger_target)
  logger.level = Logger::WARN

  responder = lambda { |request, response|
    # ...and who's your friend over there, mr. ducky? maybe the want a punch, too.
    class << response
      def set_error(ex, backtrace = false)
        bt = ex.backtrace.reject { |line| Capybara.backtrace_clean_patterns.any? { |pattern| line[pattern] } }

        Capybara.logger_target << bt.collect { |line| "  #{line}\n" }.join
        Capybara.logger_target << "\n"
      end
    end
  }

  Rack::Handler::WEBrick.run(app, :Port => port, :AccessLog => [], :Logger => logger, :RequestCallback => responder)
end

Before do
  Capybara.logger_target.rewind
  Capybara.logger_target.truncate(0)
end

AfterStep do
  Capybara.logger_target.rewind

  data = Capybara.logger_target.read
  $stderr.puts data if !data.empty?

  Capybara.logger_target.truncate(0)
end

@zedtux The capybara logger.level is set to Logger::WARN. You can set it to info or debug to get more output.