diff -u b/core/modules/system/tests/modules/test_page_test/src/Form/TestForm.php b/core/modules/system/tests/modules/test_page_test/src/Form/TestForm.php
--- b/core/modules/system/tests/modules/test_page_test/src/Form/TestForm.php
+++ b/core/modules/system/tests/modules/test_page_test/src/Form/TestForm.php
@@ -76,7 +76,7 @@
       '#value' => 'Duplicate button 2',
     ];
 
-    $form['test_textarea_with_newline'] =[
+    $form['test_textarea_with_newline'] = [
       '#type' => 'textarea',
       '#title' => 'Textarea with newline',
       '#default_value' => "Test text with\nnewline",