54 | Chapter 2: ActiveSupport and RailTies
(rdb:1) n
.../gems/ruport-1.2.0/lib/ruport/data/table.rb:806 case(args[0])
(rdb:1)
.../gems/ruport-1.2.0/lib/ruport/data/table.rb:807 when Array
(rdb:1)
.../gems/ruport-1.2.0/lib/ruport/data/table.rb:810 when /\.csv/
(rdb:1) c
$The debugger has many other commands and features. Breakpoints can be set and
cleared on arbitrary lines or methods, and they can be conditional:
(rdb:1) break table.rb:805 if args.first =~ /\.csv/
Set breakpoint 1 at table.rb:805
(rdb:1) c
Breakpoint 1 at table.rb:805
.../gems/ruport-1.2.0/lib/ruport/data/table.rb:805 table=
(rdb:1)Theirbcommand (still experimental) will start up an interactive Ruby session
within the context of the current code, allowing you to examine the environment:
.../gems/ruport-1.2.0/lib/ruport/data/table.rb:805 table=
(rdb:1) irb
>> pp args
["time.csv"]
=> nil
>>Thehelp command will show you information on the available command lan-
guage—there are several more commands and options available.
Debugging Rails with ruby-debug
Now that we understand the basics of the debugger console, we can see how it inte-
grates with Rails. The process is quite simple and easy; ruby-debug is built to be used
with Rails with virtually no setup.
- Require the ruby-debug library fromconfig/environments/development.rbso that
it is only loaded in the development environment:
require 'ruby-debug' - Insert a call todebuggeranywhere you want to stop the application’s execution
and drop into the debugger.
class SignupController < ApplicationController
def check_for_service
debugger
@query = params[:q]
(...)- Start up the Rails server. The debugger only works with WEBrick and Mon-
grel, because the running code still has access to the tty under those servers.