Issue #3316816 by Wim Leers, nod_: Stabilize FunctionalJavascript testing...

    $not_clickable_exception = NULL;

    $result = $this->waitFor(10, function () use (&$not_clickable_exception, $xpath, $value) {

      try {

        // \Behat\Mink\Driver\Selenium2Driver::setValue() will call .blur() on

        // the element, modify that to trigger the "input" and "change" events

        // instead. They indicate the value has changed, rather than implying

        // user focus changes.

        $this->executeJsOnXpath($xpath, <<<JS

var node = {{ELEMENT}};

var original = node.blur;

node.blur = function() {

  node.dispatchEvent(new Event("input", {bubbles:true}));

  node.dispatchEvent(new Event("change", {bubbles:true}));

  // Do not wait for the debounce, which only triggers the 'formUpdated` event

  // up to once every 0.3 seconds. In tests, no humans are typing, hence there

  // is no need to debounce.

  // @see Drupal.behaviors.formUpdated

  node.dispatchEvent(new Event("formUpdated", {bubbles:true}));

  node.blur = original;

};

JS);

        parent::setValue($xpath, $value);

        return TRUE;

      }