diff -u b/core/modules/node/src/Tests/NodeEditFormTest.php b/core/modules/node/src/Tests/NodeEditFormTest.php
--- b/core/modules/node/src/Tests/NodeEditFormTest.php
+++ b/core/modules/node/src/Tests/NodeEditFormTest.php
@@ -118,8 +118,8 @@
 
     // Check that details form element opens when there are errors on child
     // elements.
-    $this->drupalGet("node/" . $node->id() . "/edit");
-    $edit = array();
+    $this->drupalGet('node/' . $node->id() . '/edit');
+    $edit = [];
     // This invalid date will trigger an error.
     $edit['created[0][value][date]'] = $this->randomMachineName(8);
     // Get the current amount of open details elements.