Awesome
Deadweight
WARNING
This project is no longer maintained. I recommend that you use a different tool. I don't have a specific one to suggest, having never used any, but PurifyCSS and UnCSS both seem to be actively worked on.
Overview
Deadweight is a CSS coverage tool. Given a set of stylesheets and a set of URLs, it determines which selectors are actually used and reports which can be "safely" deleted.
Screencast!
Ryan Bates has worked his magic once again. Head over here for an excellent introduction to Deadweight.
How to Install It
$ gem install deadweight
How to Use It
There are multiple ways to use Deadweight. It's designed to be completely agnostic of whatever framework (or indeed language) your website is built on, but optimised for Ruby and Rails.
Run it From the Command Line
$ deadweight -s styles.css -s ie.css index.html about.html
$ deadweight -s http://www.tigerbloodwins.com/index.css http://www.tigerbloodwins.com/
$ deadweight --root http://kottke.org/ -s '/templates/2009/css.php?p=mac' / /everfresh /about
Integrate it With Your Integration Tests
Deadweight can hijack your Rails integration tests (both the spartan Test::Unit type and the refreshing Cucumber variety), capturing every page that is returned by your app during testing and saving you the trouble of manually specifying a ton of URLs and login processses.
First, put this in your Gemfile
:
group :test do
gem 'colored'
gem 'deadweight', :require => 'deadweight/hijack/rails'
end
Then, run your integration tests with the environment variable DEADWEIGHT
set to true
:
rake test DEADWEIGHT=true
rake cucumber DEADWEIGHT=true
Let me know how it goes. It's not terribly customisable at the moment (you can't specify what exact stylesheets to look at, or what selectors to ignore). I'm looking for your feedback on how you'd like to be able to do that.
Rake Task
# lib/tasks/deadweight.rake
require 'deadweight'
Deadweight::RakeTask.new do |dw|
dw.stylesheets = ["/stylesheets/style.css"]
dw.pages = ["/", "/page/1", "/about"]
end
Running rake deadweight
will output all unused rules, one per line. Note that it looks at http://localhost:3000
by default, so you'll need to have script/server
(or whatever your server command looks like) running.
Call it Directly from Ruby
require 'deadweight'
dw = Deadweight.new
dw.stylesheets = ["/stylesheets/style.css"]
dw.pages = ["/", "/page/1", "/about"]
puts dw.run
Pipe In CSS Rules from STDIN
$ cat styles.css | deadweight index.html
Use it as an HTTP Proxy
$ deadweight -l deadweight.log -s styles.css -w http://github.com/ -P
Setting the Root URL
By default, Deadweight uses http://localhost:3000
as the base URL for all paths. To change it, set root
:
dw.root = "http://staging.example.com" # staging server
dw.root = "http://example.com/staging-area" # urls can have paths in
dw.root = "/path/to/some/html" # local paths work too
What About Stuff Added by Javascript?
Deadweight is completely ignorant of classes, IDs or tags added by your Javascript layer, but you can filter them out by setting ignore_selectors
:
dw.ignore_selectors = /hover|lightbox|superimposed_kittens/
The command-line tool also has basic support for Lyndon with the -L
flag, which simply pipes all HTML through the lyndon
executable to execute any embedded or linked JS.
You Can Use Mechanize for Complex Stuff
Set mechanize
to true
and add a Proc to pages
(rather than a String), and Deadweight will execute it using Mechanize:
dw.mechanize = true
# go through the login form to get to a protected URL
dw.pages << proc {
fetch('/login')
form = agent.page.forms.first
form.username = 'username'
form.password = 'password'
agent.submit(form)
fetch('/secret-page')
}
# use HTTP basic auth
dw.pages << proc {
agent.auth('username', 'password')
fetch('/other-secret-page')
}
The agent
method returns the Mechanize instance. The fetch
method is a wrapper around agent.get
that will abort in the event of an HTTP error status.
If You Install colored
, It'll Look Nicer
gem install colored
Copyright
Copyright (c) 2009 Aanand Prasad. See LICENSE for details.