A (very) small library that counts selectors in a CSS file.

This is mainly useful to detect when your CSS files have crossed the 4095 selector limit imposed by Internet Explorer 9 and lower.

Installation

gem install css_counter

Usage

require 'css_counter'

css = <<-EOS
  h1 { color: red }
  h2 { color: green }
EOS

CssCounter.new(css).selectors
=> 2

Rails

To ensure none of the compiled CSS files in your rails app exceed the IE selector limit, there’s a rake task you can run as part of a build process.

Add css_counter to your application Gemfile, and then run:

bundle exec rake css_counter:check_selectors