browsernizr/test/css/multiplebgs.js

Modernizr wrapper for use with browserify

/*!
{
  "name": "CSS Multiple Backgrounds",
  "caniuse": "multibackgrounds",
  "property": "multiplebgs",
  "tags": ["css"]
}
!*/
var Modernizr = require('./../../lib/Modernizr.js');
var createElement = require('./../../lib/createElement.js');
  // Setting multiple images AND a color on the background shorthand property
  // and then querying the style.background property value for the number of
  // occurrences of "url(" is a reliable method for detecting ACTUAL support for this!

  Modernizr.addTest('multiplebgs', function() {
    var style = createElement('a').style;
    style.cssText = 'background:url(https://),url(https://),red url(https://)';

    // If the UA supports multiple backgrounds, there should be three occurrences
    // of the string "url(" in the return value for elemStyle.background
    return (/(url\s*\(.*?){3}/).test(style.background);
  });