MAGETWO-54456: Random FAT test fails CatalogRuleStaging_Create_ForNewCustomerGroup_ApplyAsPercentage

Author: serhii-balko

dev/tests/functional/tests/app/Magento/CatalogRule/Test/Block/Adminhtml/Promo/Catalog/Edit/PromoForm.php

@@ -15,6 +15,13 @@
  */
 class PromoForm extends FormSections
 {
+    /**
+     * Magento form loader.
+     *
+     * @var string
+     */
+    protected $spinner = '[data-role="spinner"]';
+    
     /**
      * Fill form with tabs.
      *
@@ -25,6 +32,7 @@ class PromoForm extends FormSections
      */
     public function fill(FixtureInterface $fixture, SimpleElement $element = null, array $replace = null)
     {
+        $this->waitPageToLoad();
         $sections = $this->getFixtureFieldsByContainers($fixture);
         if ($replace) {
             $sections = $this->prepareData($sections, $replace);
@@ -55,4 +63,15 @@ protected function prepareData(array $tabs, array $replace)
 
         return $tabs;
     }
+
+    /**
+     * Wait page to load.
+     *
+     * @return void
+     */
+    protected function waitPageToLoad()
+    {
+        $this->waitForElementVisible($this->header);
+        $this->waitForElementNotVisible($this->spinner);
+    }
 }