modernizr/feature-detects/css/hsla.js

Modernizr is a JavaScript library that detects HTML5 and CSS3 features in the user’s browser.

/*!
{
  "name": "CSS HSLA Colors",
  "caniuse": "css3-colors",
  "property": "hsla",
  "tags": ["css"]
}
!*/
define(['Modernizr', 'createElement', 'contains'], function(Modernizr, createElement, contains) {
  Modernizr.addTest('hsla', function() {
    var style = createElement('a').style;
    style.cssText = 'background-color:hsla(120,40%,100%,.5)';
    return contains(style.backgroundColor, 'rgba') || contains(style.backgroundColor, 'hsla');
  });
});