Let’s get interactive. You can learn a lot about your application from irb and
by extension, script/console.
Wirble: colors
Color matters. You’re picky about your text editor syntax highlighting and maybe you use the excellent redgreen gem for colors in your test backtraces. Gotta have it in irb, too.
First, install Wirble:
sudo gem install wirble
Then, in your ~/.irbrc:
require 'rubygems'
require 'wirble'
Wirble.init
Wirble.colorize
Wirble: history
Wirble has an added bonus: history.
irb(main):001:0> history = "History?"
=> "History?"
irb(main):002:0> exit
Without Wirble, if you drop back into irb, you can’t arrow up to your previous commands. With Wirble, you can.
Wirble: auto-completion
As if that’s not enough, Wirble gives you auto-completion, too. In irb:
>> un_momento = "Spanish for like, 'hold the phone!'"
=> "Spanish for like, 'hold the phone!'"
Type, un, then tab:
>> un
un_momento undef unless untaint untrace_var until
Local methods
Stick this in your ~/.irbrc:
# Easily print methods local to an object's class
class Object
def local_methods
(methods - Object.instance_methods).sort
end
end
Use the local_methods method like this:
>> class BasketballPlayer
>> attr_accessor :name
>>
?> def champion?
>> name == "Kevin Garnett"
>> end
>> end
=> nil
>> kevin_garnett = BasketballPlayer.new
=> #<BasketballPlayer:0x11988f8>
>> kevin_garnett.name = "Kevin Garnett"
=> "Kevin Garnett"
>> kevin_garnett.champion?
=> true
>> kevin_garnett.local_methods
=> ["champion?", "name", "name="]
Aliases
Don’t forget you can alias in irb. The only one I have is:
alias q exit
It makes irb feel more Vim-ish.
Create test fixtures for a third party service
Your app uses the Flickr API. You want your test suite to use legitimate data but not hit the service.
Given the actual call to the service is:
FlickrClient.search("Bruce Springsteen")
Run the query in script/console and convert the data into yaml:
yaml = FlickrClient.search("Bruce Springsteen").to_yaml
Then use your old Ruby friend, File.open with the write option (w) to dump it to a file:
File.open("test/fixtures/flickr/springsteen.yml", "w") { |file| file << yaml }
Add this to your test_helper.rb:
def load_yaml_fixture(path)
absolute_path = File.join(RAILS_ROOT, "test", "fixtures", path)
YAML::load_file absolute_path
end
Voila, when you need to mock out calls to the third party service, you can now use this in your test code:
load_yaml_fixture("springsteen.yml")
This pattern is repeatable for any third party service. Just replace the actual call with whatever you’re working on, and name the fixture something intention-revealing.
Print SQL to standard out
Oftentimes script/console is used for debugging, and what better way to do
that than to get the SQL
generated by each method call. Stick this in your ~/.irbrc:
# Log to STDOUT if in Rails
if ENV.include?('RAILS_ENV') && !Object.const_defined?('RAILS_DEFAULT_LOGGER')
require 'logger'
RAILS_DEFAULT_LOGGER = Logger.new(STDOUT)
end
This gets you:
>> videos = Video.limited(3)
Video Load (0.4ms) SELECT * FROM `videos` LIMIT 3
=> [#<Video id: 1, ...>]
Without the ~/.irbrc love, you’d be missing:
Video Load (0.4ms) SELECT * FROM `videos` LIMIT 3
pp
After you’ve required rubygems for Wirble, require pretty print, too:
require 'pp'
This is just a nice way to have better formatting at your fingertips. It’s especially helpful when dealing with an Array of ActiveRecord objects:
>> pp videos
[#<Video id: 1, youtube_id: "TcMklv40YMY", name: "Merb, Rubinius and the
Engine Yard Stack", upload_time: nil, view_count: 6171, description: "Google
Tech Talks\nOctober 20, 2008\n\nABSTRACT\n\nIn th...", created_at: "2008-12-21
00:32:33", updated_at: "2008-12-21 00:32:33">, #<Video id: 2, youtube_id:
"JySmT-dGOj0", name: "MERB SPORTS Team-Vorstellung 2008", upload_time: nil,
view_count: 495, description: "MERB SPORTS stellt sich für die VDRM-Saison 2008
v...", created_at: "2008-12-21 00:32:33", updated_at: "2008-12-21 00:32:33">,
#<Video id: 3, youtube_id: "6bc-FNNWIsM", name: "Merb && Moi", upload_time:
nil, view_count: 58, description: "Amusing yes?", created_at: "2008-12-21
00:32:33", updated_at: "2008-12-21 00:32:33">]
