Trap Capybara Stack Trace

capybara_debug.rb

### Show stack trace for 500 errors
### (adapted from https://gist.github.com/1079020) 

# Given an application, yield to a block to handle exceptions 
class ExceptionRaiserApp
  def initialize(app)
    @app = app
  end

  def call(env)
    @app.call(env)
  rescue => e
    backtrace = [ "#{'*'*20} #{e.to_s} #{'*'*20}",
                  '',
                  e.message,
                  '',
                  Rails.backtrace_cleaner.clean(e.backtrace, :silent),
                  '',
                  '*'*80,
                  '' ].join("\n\t")

    # log the backtrace 
    Rails.logger.error backtrace

    # re-raise so capybara gets a 500 and knows what's up 
    raise e
  end
end

Capybara.app = ExceptionRaiserApp.new(MyApp::Application)