Ensure your CSS won't be discarded by IE 9 and below because of crazy stylesheets limitation of legacy IE.
npm install css-selectors-countCount selectors in your CSS file in order to make sure it don't exceed the limitation of legacy IE browsers.
``
var csc = require('css-selectors-count');
var fs = require('fs');
fs.readFile('style.css', {encoding: 'utf8'}, function(err, file) {
if(err) throw err;
console.log(csc(file)); // return a object like { rules: 1, selectors: 10}
});
`
`
$ npm run test
$ npm run coverage
MIT