Get notified when you're attempting jQuery method calls on an empty collection

gistfile1.js

for (var i in $.fn) (function(method, name) {
  // ignore traversal/selection methods
  if (typeof method != 'function' || [
    'constructor', 'init', 'find', 'add', 'next', 'nextUnil', 'prevUntil',
    'parents', 'closest', 'eq', 'filter', 'has', 'first', 'siblings',
    'last', 'map', 'not', 'slice', 'addBack', 'andSelf', 'contents', 'prev',
    'end', 'not', 'children', 'nextAll', 'prevAll', 'parent', 'parentsUntil'
  ].indexOf(name) > -1) {
    return;
  }
  $.fn[name] = function() {
    if (this.length === 0) {
      console.warn('Trying to call ' + name + '() on an empty collection: ' + this.selector);
    }
    return method.apply(this, arguments);
  };
}($.fn[i], i));