modernizr/feature-detects/workers/dataworkers.js

/*!
{
  "name": "Workers from Data URIs",
  "property": "dataworkers",
  "tags": ["performance", "workers"],
  "builderAliases": ["workers_dataworkers"],
  "notes": [{
    "name": "W3C Spec",
    "href": "https://www.w3.org/TR/workers/"
  }],
  "knownBugs": ["This test may output garbage to console."],
  "authors": ["Jussi Kalliokoski"],
  "async": true
}
!*/
/* DOC
Detects support for creating Web Workers from Data URIs.
*/
define(['Modernizr', 'addTest'], function(Modernizr, addTest) {
  Modernizr.addAsyncTest(function() {
    try {
      var data = 'Modernizr',
        worker = new Worker('data:text/javascript;base64,dGhpcy5vbm1lc3NhZ2U9ZnVuY3Rpb24oZSl7cG9zdE1lc3NhZ2UoZS5kYXRhKX0=');

      worker.onmessage = function(e) {
        worker.terminate();
        addTest('dataworkers', data === e.data);
        worker = null;
      };

      // Just in case...
      worker.onerror = function() {
        addTest('dataworkers', false);
        worker = null;
      };

      setTimeout(function() {
        addTest('dataworkers', false);
      }, 200);

      worker.postMessage(data);
    } catch (e) {
      setTimeout(function() {
        addTest('dataworkers', false);
      }, 0);
    }
  });
});