Find CSS selectors greater than n

findLongSelectors.js

function findLongSelectors(n) {

  var sheets = document.styleSheets;
  var splitRule = /\s*,\s*/;
  var splitWhitespace = /\s+/;
  var longRules = [];

  [].forEach.call(document.styleSheets, function(styleSheet) {
    if (!styleSheet.cssRules) return;
    [].forEach.call(styleSheet.cssRules, function(cssRule) {
      if (!cssRule.selectorText) return;
      var selectorTexts = cssRule.selectorText.split(splitRule);
      selectorTexts.forEach(function(selectorText) {
        var selectors = selectorText.split(splitWhitespace);
        var filtered = selectors.filter(function(selector) {
          return selector.length > 1;
        });
        if (filtered.length > n) {
          longRules.push(selectorText);
        }
      });
    });
  });
  return longRules;
}

usage.js

var longRules = findLongSelectors(3);
console.log(longRules.join('\n'));