How to kill your jQuery AJAX call with an HTML valid url

amp_maddess.js

// Situation: /echo need a `key` as a GET param
//  - key: access token
//    HTTP 200 - any `key`
//    HTTP 403 - no `key`
var good_url = "/echo/?version=1&key=4bf3D"; //Good URL that will not break the server but it will fail the HTML validator
var html_url = "/echo/?version=1&key=4bf3D"; //HTML valid URL that will pass the html validator but fail $.get

$.get(good_url)
  .done(function(){ console.log("OK"); }) //200, OK 
  .fail(function(){ console.log("Ka-boom!")});
  
$.get(html_url)
  .done(function(){ console.log("OK"); })
  .fail(function(){ console.log("Ka-boom!")}); //403, Ka-boom! (Tested in FF & Chrome) 
                                               // Reason: `key` is `amp;key` now

// Solution: unescape/decode as most HTML element does
// Source: http://stackoverflow.com/a/7656296
var decode_url = $("<a>").html(html_url).text();

$.get(decode_url)
  .done(function(){ console.log("OK"); })
  .fail(function(){ console.log("Ka-boom!")});

Note: You can use @data-url in any html element to replace the code above.