jsCheatsheet.js

// #1
// Polyfill a few basic things.
['filter', 'forEach', 'map', 'reduce'].forEach(function (name) {
  Array[name] = function (array, callback, init) {
    return [][name].call(array, callback, init);
  };
});

// Automatically set up asynchronous JSON forms (all with a 'method' attribute).
// Array.forEach(document.querySelectorAll('form'), function (form) { ....
// url - https://github.com/jankeromnes/janitor/blob/ec1b1f7f0c955d18047be8460a75e46fbd33bf60/static/js/janitor.js

// #2