instance method start

# File railties/lib/rails/commands/console/irb_console.rb, line 81
      def start
        IRB.setup(nil)

        if !Rails.env.local? && !ENV.key?("IRB_USE_AUTOCOMPLETE")
          IRB.conf[:USE_AUTOCOMPLETE] = false
        end

        env = colorized_env
        prompt_prefix = "%N(#{env})"
        IRB.conf[:IRB_NAME] = @app.name

        IRB.conf[:PROMPT][:RAILS_PROMPT] = {
          PROMPT_I: "#{prompt_prefix}> ",
          PROMPT_S: "#{prompt_prefix}%l ",
          PROMPT_C: "#{prompt_prefix}* ",
          RETURN: "=> %s\n"
        }

        if current_filter = IRB.conf[:BACKTRACE_FILTER]
          IRB.conf[:BACKTRACE_FILTER] = -> (backtrace) do
            backtrace = current_filter.call(backtrace)
            Rails.backtrace_cleaner.filter(backtrace)
          end
        else
          IRB.conf[:BACKTRACE_FILTER] = -> (backtrace) do
            Rails.backtrace_cleaner.filter(backtrace)
          end
        end

        # Because some users/libs use Rails::ConsoleMethods to extend Rails console,
        # we still include it for backward compatibility.
        IRB::ExtendCommandBundle.include ConsoleMethods

        # Respect user's choice of prompt mode.
        IRB.conf[:PROMPT_MODE] = :RAILS_PROMPT if IRB.conf[:PROMPT_MODE] == :DEFAULT
        IRB::Irb.new.run(IRB.conf)
      end