diff --git a/core/modules/locale/tests/src/Functional/LocaleConfigTranslationImportTest.php b/core/modules/locale/tests/src/Functional/LocaleConfigTranslationImportTest.php
index b0a4b5f28e..9187bf0c0d 100644
--- a/core/modules/locale/tests/src/Functional/LocaleConfigTranslationImportTest.php
+++ b/core/modules/locale/tests/src/Functional/LocaleConfigTranslationImportTest.php
@@ -206,7 +206,7 @@ public function testLocaleRemovalAndConfigOverridePreserve() {
     $this->drupalPostForm('admin/config/regional/translate', $search, t('Filter'));
     $textareas = $this->xpath('//textarea');
     $textarea = current($textareas);
-    $lid = (string) $textarea[0]['name'];
+    $lid = (string) $textarea->getAttribute('name');
     $edit = [
       $lid => '',
     ];
diff --git a/core/modules/locale/tests/src/Functional/LocaleConfigTranslationTest.php b/core/modules/locale/tests/src/Functional/LocaleConfigTranslationTest.php
index 701ef585f2..cfef00852f 100644
--- a/core/modules/locale/tests/src/Functional/LocaleConfigTranslationTest.php
+++ b/core/modules/locale/tests/src/Functional/LocaleConfigTranslationTest.php
@@ -76,7 +76,7 @@ public function testConfigTranslation() {
     $this->drupalPostForm('admin/config/regional/translate', $search, t('Filter'));
     $textareas = $this->xpath('//textarea');
     $textarea = current($textareas);
-    $lid = (string) $textarea[0]['name'];
+    $lid = (string) $textarea->getAttribute('name');
     $edit = [
       $lid => $message,
     ];
@@ -100,7 +100,7 @@ public function testConfigTranslation() {
     $this->drupalPostForm('admin/config/regional/translate', $search, t('Filter'));
     $textareas = $this->xpath('//textarea');
     $textarea = current($textareas);
-    $lid = (string) $textarea[0]['name'];
+    $lid = (string) $textarea->getAttribute('name');
     $edit = [
       $lid => 'D',
     ];
@@ -143,7 +143,7 @@ public function testConfigTranslation() {
     ];
     $this->drupalPostForm('admin/config/regional/translate', $search, t('Filter'));
     $textarea = current($this->xpath('//textarea'));
-    $lid = (string) $textarea[0]['name'];
+    $lid = (string) $textarea->getAttribute('name');
     $edit = [
       $lid => $image_style_label,
     ];
@@ -175,7 +175,7 @@ public function testConfigTranslation() {
     ];
     $this->drupalPostForm('admin/config/regional/translate', $search, t('Filter'));
     $textarea = current($this->xpath('//textarea'));
-    $lid = (string) $textarea[0]['name'];
+    $lid = (string) $textarea->getAttribute('name');
     $edit = [
       $lid => $category_label,
     ];
diff --git a/core/modules/locale/tests/src/Functional/LocaleJavascriptTranslationTest.php b/core/modules/locale/tests/src/Functional/LocaleJavascriptTranslationTest.php
index 1d5b00548c..5b146b4cba 100644
--- a/core/modules/locale/tests/src/Functional/LocaleJavascriptTranslationTest.php
+++ b/core/modules/locale/tests/src/Functional/LocaleJavascriptTranslationTest.php
@@ -21,7 +21,7 @@ class LocaleJavascriptTranslationTest extends BrowserTestBase {
   public static $modules = ['locale', 'locale_test'];
 
   public function testFileParsing() {
-    $filename = __DIR__ . '/../../tests/locale_test.js';
+    $filename = __DIR__ . '/../../locale_test.js';
 
     // Parse the file to look for source strings.
     _locale_parse_js_file($filename);
@@ -138,8 +138,9 @@ public function testLocaleTranslationJsDependencies() {
     $js_translation_files = \Drupal::state()->get('locale.translation.javascript');
     $js_filename = $prefix . '_' . $js_translation_files[$prefix] . '.js';
 
+    $content = $this->getSession()->getPage()->getcontent();
     // Assert translations JS is included before drupal.js.
-    $this->assertTrue(strpos($this->content, $js_filename) < strpos($this->content, 'core/misc/drupal.js'), 'Translations are included before Drupal.t.');
+    $this->assertTrue(strpos($content, $js_filename) < strpos($content, 'core/misc/drupal.js'), 'Translations are included before Drupal.t.');
   }
 
 }
diff --git a/core/modules/locale/tests/src/Functional/LocaleTranslationUiTest.php b/core/modules/locale/tests/src/Functional/LocaleTranslationUiTest.php
index 90603282ed..c21410f2bc 100644
--- a/core/modules/locale/tests/src/Functional/LocaleTranslationUiTest.php
+++ b/core/modules/locale/tests/src/Functional/LocaleTranslationUiTest.php
@@ -89,7 +89,7 @@ public function testStringTranslation() {
 
     // Assume this is the only result, given the random name.
     $textarea = current($this->xpath('//textarea'));
-    $lid = (string) $textarea[0]['name'];
+    $lid = (string) $textarea->getAttribute('name');
     $edit = [
       $lid => $translation,
     ];
@@ -112,7 +112,7 @@ public function testStringTranslation() {
     ];
     $this->drupalPostForm('admin/config/regional/translate', $search, t('Filter'));
     $textarea = current($this->xpath('//textarea'));
-    $lid = (string) $textarea[0]['name'];
+    $lid = (string) $textarea->getAttribute('name');
     $edit = [
       $lid => $translation_to_en,
     ];
@@ -155,7 +155,7 @@ public function testStringTranslation() {
     ];
     $this->drupalPostForm('admin/config/regional/translate', $search, t('Filter'));
     $textarea = current($this->xpath('//textarea'));
-    $lid = (string) $textarea[0]['name'];
+    $lid = (string) $textarea->getAttribute('name');
     $edit = [
       $lid => 'Please enter your Llama username.',
     ];
@@ -189,7 +189,7 @@ public function testStringTranslation() {
     $this->drupalPostForm('admin/config/regional/translate', $search, t('Filter'));
     // Assume this is the only result, given the random name.
     $textarea = current($this->xpath('//textarea'));
-    $lid = (string) $textarea[0]['name'];
+    $lid = (string) $textarea->getAttribute('name');
     $edit = [
       $lid => '',
     ];
@@ -248,7 +248,7 @@ public function testJavaScriptTranslation() {
     $this->drupalPostForm('admin/config/regional/translate', $search, t('Filter'));
 
     $textarea = current($this->xpath('//textarea'));
-    $lid = (string) $textarea[0]['name'];
+    $lid = (string) $textarea->getAttribute('name');
     $edit = [
       $lid => $this->randomMachineName(),
     ];
@@ -309,15 +309,15 @@ public function testStringValidation() {
     // Find the edit path.
 
     $textarea = current($this->xpath('//textarea'));
-    $lid = (string) $textarea[0]['name'];
+    $lid = (string) $textarea->getAttribute('name');
     foreach ($bad_translations as $translation) {
       $edit = [
         $lid => $translation,
       ];
       $this->drupalPostForm('admin/config/regional/translate', $edit, t('Save translations'));
       // Check for a form error on the textarea.
-      $form_class = $this->xpath('//form[@id="locale-translate-edit-form"]//textarea/@class');
-      $this->assertNotIdentical(FALSE, strpos($form_class[0], 'error'), 'The string was rejected as unsafe.');
+      $form_class = $this->xpath('//form[@id="locale-translate-edit-form"]//textarea');
+      $this->assertNotIdentical(FALSE, strpos($form_class->getAttribute('class'), 'error'), 'The string was rejected as unsafe.');
       $this->assertNoText(t('The string has been saved.'), 'The string was not saved.');
     }
   }
@@ -399,7 +399,7 @@ public function testStringSearch() {
     // Assume this is the only result, given the random name.
     // We save the lid from the path.
     $textarea = current($this->xpath('//textarea'));
-    $lid = (string) $textarea[0]['name'];
+    $lid = (string) $textarea->getAttribute('name');
     $edit = [
       $lid => $translation,
     ];
@@ -503,7 +503,7 @@ public function testUICustomizedStrings() {
 
     // Submit the translations without changing the translation.
     $textarea = current($this->xpath('//textarea'));
-    $lid = (string) $textarea[0]['name'];
+    $lid = (string) $textarea->getAttribute('name');
     $edit = [
       $lid => $translation->getString(),
     ];
@@ -522,7 +522,7 @@ public function testUICustomizedStrings() {
 
     // Submit the translations with a new translation.
     $textarea = current($this->xpath('//textarea'));
-    $lid = (string) $textarea[0]['name'];
+    $lid = (string) $textarea->getAttribute('name');
     $edit = [
       $lid => $this->randomMachineName(100),
     ];
diff --git a/core/modules/locale/tests/src/Functional/LocaleUpdateCronTest.php b/core/modules/locale/tests/src/Functional/LocaleUpdateCronTest.php
index b24ce78b96..d0d5379139 100644
--- a/core/modules/locale/tests/src/Functional/LocaleUpdateCronTest.php
+++ b/core/modules/locale/tests/src/Functional/LocaleUpdateCronTest.php
@@ -2,6 +2,8 @@
 
 namespace Drupal\Tests\locale\Functional;
 
+use Drupal\Tests\Traits\Core\CronRunTrait;
+
 /**
  * Tests for using cron to update project interface translations.
  *
@@ -9,6 +11,8 @@
  */
 class LocaleUpdateCronTest extends LocaleUpdateBase {
 
+  use CronRunTrait;
+
   protected $batchOutput = [];
 
   /**