MDL-62514 behat: Add a wait_for_pending_js to form field

lib/behat/behat_base.php

@@ -28,10 +28,11 @@
 
 // NOTE: no MOODLE_INTERNAL test here, this file may be required by behat before including /config.php.
 
-use Behat\Mink\Exception\DriverException,
-    Behat\Mink\Exception\ExpectationException as ExpectationException,
-    Behat\Mink\Exception\ElementNotFoundException as ElementNotFoundException,
-    Behat\Mink\Element\NodeElement as NodeElement;
+use Behat\Mink\Exception\DriverException;
+use Behat\Mink\Exception\ExpectationException;
+use Behat\Mink\Exception\ElementNotFoundException;
+use Behat\Mink\Element\NodeElement;
+use Behat\Mink\Session;
 
 /**
  * Steps definitions base class.
@@ -709,23 +710,30 @@ protected function resize_window($windowsize, $viewport = false) {
     /**
      * Waits for all the JS to be loaded.
      *
-     * @throws \Exception
-     * @throws NoSuchWindow
-     * @throws UnknownError
-     * @return bool True or false depending whether all the JS is loaded or not.
+     * @return  bool Whether any JS is still pending completion.
      */
     public function wait_for_pending_js() {
-        // Waiting for JS is only valid for JS scenarios.
         if (!$this->running_javascript()) {
-            return;
+            // JS is not available therefore there is nothing to wait for.
+            return false;
         }
 
+        return static::wait_for_pending_js_in_session($this->getSession());
+    }
+
+    /**
+     * Waits for all the JS to be loaded.
+     *
+     * @param   Session $session The Mink Session where JS can be run
+     * @return  bool Whether any JS is still pending completion.
+     */
+    public static function wait_for_pending_js_in_session(Session $session) {
         // We don't use behat_base::spin() here as we don't want to end up with an exception
         // if the page & JSs don't finish loading properly.
         for ($i = 0; $i < self::EXTENDED_TIMEOUT * 10; $i++) {
             $pending = '';
             try {
-                $jscode = '
+                $jscode = trim(preg_replace('/\s+/', ' ', '
                     return (function() {
                         if (typeof M === "undefined") {
                             if (document.readyState === "complete") {
@@ -740,8 +748,8 @@ public function wait_for_pending_js() {
                         } else {
                             return "incomplete"
                         }
-                    }());';
-                $pending = $this->getSession()->evaluateScript($jscode);
+                    }());'));
+                $pending = $session->evaluateScript($jscode);
             } catch (NoSuchWindow $nsw) {
                 // We catch an exception here, in case we just closed the window we were interacting with.
                 // No javascript is running if there is no window right?
@@ -762,7 +770,7 @@ public function wait_for_pending_js() {
             usleep(100000);
         }
 
-        // Timeout waiting for JS to complete. It will be catched and forwarded to behat_hooks::i_look_for_exceptions().
+        // Timeout waiting for JS to complete. It will be caught and forwarded to behat_hooks::i_look_for_exceptions().
         // It is unlikely that Javascript code of a page or an AJAX request needs more than self::EXTENDED_TIMEOUT seconds
         // to be loaded, although when pages contains Javascript errors M.util.js_complete() can not be executed, so the
         // number of JS pending code and JS completed code will not match and we will reach this point.

lib/behat/form_field/behat_form_field.php

@@ -172,6 +172,20 @@ protected function running_javascript() {
         return get_class($this->session->getDriver()) !== 'Behat\Mink\Driver\GoutteDriver';
     }
 
+    /**
+     * Waits for all the JS activity to be completed.
+     *
+     * @return bool Whether any JS is still pending completion.
+     */
+    protected function wait_for_pending_js() {
+        if (!$this->running_javascript()) {
+            // JS is not available therefore there is nothing to wait for.
+            return false;
+        }
+
+        return behat_base::wait_for_pending_js_in_session($this->session);
+    }
+
     /**
      * Gets the field internal id used by selenium wire protocol.
      *