modernizr/feature-detects/css/positionsticky.js

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

/*!
{
  "name": "CSS position: sticky",
  "property": "csspositionsticky",
  "tags": ["css"]
}
!*/
define(['Modernizr', 'createElement', 'prefixes'], function( Modernizr, createElement, prefixes ) {
  // Sticky positioning - constrains an element to be positioned inside the
  // intersection of its container box, and the viewport.
  Modernizr.addTest('csspositionsticky', function() {
    var prop = 'position:';
    var value = 'sticky';
    var el = createElement('modernizr');
    var mStyle = el.style;

    mStyle.cssText = prop + prefixes.join(value + ';' + prop).slice(0, -prop.length);

    return mStyle.position.indexOf(value) !== -1;
  });
});