diff -u b/core/modules/text/tests/src/FunctionalJavascript/TextareaWithSummaryTest.php b/core/modules/text/tests/src/FunctionalJavascript/TextareaWithSummaryTest.php
--- b/core/modules/text/tests/src/FunctionalJavascript/TextareaWithSummaryTest.php
+++ b/core/modules/text/tests/src/FunctionalJavascript/TextareaWithSummaryTest.php
@@ -37,17 +37,17 @@
     $widget = $this->getSession()->getPage()->findById('edit-body-wrapper');
     $summary_field = $widget->findField('edit-body-0-summary');
 
-    $this->assertFalse($summary_field->isVisible(), 'Summary field is hidden by default.');
-    $this->assertFalse($widget->hasButton('Hide summary'), 'No Hide summary link by default.');
+    $this->assertEquals(FALSE, $summary_field->isVisible(), 'Summary field is hidden by default.');
+    $this->assertEquals(FALSE, $widget->hasButton('Hide summary'), 'No Hide summary link by default.');
 
     $widget->pressButton('Edit summary');
-    $this->assertFalse($widget->hasButton('Edit summary'), 'Edit summary link is removed after clicking.');
-    $this->assertTrue($summary_field->isVisible(), 'Summary field is shown.');
+    $this->assertEquals(FALSE, $widget->hasButton('Edit summary'), 'Edit summary link is removed after clicking.');
+    $this->assertEquals(TRUE, $summary_field->isVisible(), 'Summary field is shown.');
 
     $widget->pressButton('Hide summary');
-    $this->assertFalse($widget->hasButton('Hide summary'), 'Hide summary link is removed after clicking.');
-    $this->assertFalse($summary_field->isVisible(), 'Summary field is hidden again.');
-    $this->assertTrue($widget->hasButton('Edit summary'), 'Edit summary link is visible again.');
+    $this->assertEquals(FALSE, $widget->hasButton('Hide summary'), 'Hide summary link is removed after clicking.');
+    $this->assertEquals(FALSE, $summary_field->isVisible(), 'Summary field is hidden again.');
+    $this->assertEquals(TRUE, $widget->hasButton('Edit summary'), 'Edit summary link is visible again.');
   }
 
   /**
@@ -80,7 +80,7 @@
     $page = $this->getSession()->getPage();
     $summary_field = $page->findField('edit-body-0-summary');
 
-    $this->assertTrue($summary_field->isVisible(), 'Non-empty summary field is shown by default.');
+    $this->assertEquals(TRUE, $summary_field->isVisible(), 'Non-empty summary field is shown by default.');
   }
 
 }