diff --git a/core/modules/aggregator/src/Tests/UpdateFeedItemTest.php b/core/modules/aggregator/src/Tests/UpdateFeedItemTest.php
index ea48f46..9373630 100644
--- a/core/modules/aggregator/src/Tests/UpdateFeedItemTest.php
+++ b/core/modules/aggregator/src/Tests/UpdateFeedItemTest.php
@@ -37,10 +37,10 @@ public function testUpdateFeedItem() {
     );
 
     $this->drupalGet($edit['url[0][value]']);
-    $this->assertResponse(200);
+    $this->assertResponse(array(200), format_string('URL !url is accessible', array('!url' => $edit['url[0][value]'])));
 
     $this->drupalPostForm('aggregator/sources/add', $edit, t('Save'));
-    $this->assertRaw(t('The feed %name has been added.', array('%name' => $edit['title[0][value]'])), format_string('The feed !name has been added.', array('!name' => $edit['title[0][value]'])));
+    $this->assertRaw(t('The feed %name has been added.', array('%name' => $edit['title[0][value]'])), format_string('The feed @name has been added.', array('@name' => $edit['title[0][value]'])));
 
     $fid = db_query("SELECT fid FROM {aggregator_feed} WHERE url = :url", array(':url' => $edit['url[0][value]']))->fetchField();
     $feed = Feed::load($fid);
@@ -62,7 +62,7 @@ public function testUpdateFeedItem() {
     $feed->refreshItems();
 
     $after = db_query('SELECT timestamp FROM {aggregator_item} WHERE fid = :fid', array(':fid' => $feed->id()))->fetchField();
-    $this->assertTrue($before === $after, format_string('Publish timestamp of feed item was not updated (!before === !after)', array('!before' => $before, '!after' => $after)));
+    $this->assertTrue($before === $after, format_string('Publish timestamp of feed item was not updated (@before === @after)', array('@before' => $before, '@after' => $after)));
 
     // Make sure updating items works even after uninstalling a module
     // that provides the selected plugins.
diff --git a/core/modules/block_content/src/Tests/BlockContentCreationTest.php b/core/modules/block_content/src/Tests/BlockContentCreationTest.php
index 6bf250c..84f8e7f 100644
--- a/core/modules/block_content/src/Tests/BlockContentCreationTest.php
+++ b/core/modules/block_content/src/Tests/BlockContentCreationTest.php
@@ -48,8 +48,8 @@ public function testBlockContentCreation() {
     $this->drupalPostForm('block/add/basic', $edit, t('Save'));
 
     // Check that the Basic block has been created.
-    $this->assertRaw(format_string('!block %name has been created.', array(
-      '!block' => 'basic',
+    $this->assertRaw(format_string('@block %name has been created.', array(
+      '@block' => 'basic',
       '%name' => $edit['info[0][value]']
     )), 'Basic block created.');
 
@@ -95,8 +95,8 @@ public function testBlockContentCreationMultipleViewModes() {
     $this->drupalPostForm('block/add/basic', $edit, t('Save'));
 
     // Check that the Basic block has been created.
-    $this->assertRaw(format_string('!block %name has been created.', array(
-      '!block' => 'basic',
+    $this->assertRaw(format_string('@block %name has been created.', array(
+      '@block' => 'basic',
       '%name' => $edit['info[0][value]']
     )), 'Basic block created.');
 
@@ -144,8 +144,8 @@ public function testDefaultBlockContentCreation() {
     $this->drupalPostForm('block/add', $edit, t('Save'));
 
     // Check that the block has been created and that it is a basic block.
-    $this->assertRaw(format_string('!block %name has been created.', array(
-      '!block' => 'basic',
+    $this->assertRaw(format_string('@block %name has been created.', array(
+      '@block' => 'basic',
       '%name' => $edit['info[0][value]'],
     )), 'Basic block created.');
 
diff --git a/core/modules/block_content/src/Tests/BlockContentRevisionsTest.php b/core/modules/block_content/src/Tests/BlockContentRevisionsTest.php
index 8da9c54..15e7a10 100644
--- a/core/modules/block_content/src/Tests/BlockContentRevisionsTest.php
+++ b/core/modules/block_content/src/Tests/BlockContentRevisionsTest.php
@@ -69,8 +69,8 @@ public function testRevisions() {
       // Confirm the correct revision text appears.
       $loaded = entity_revision_load('block_content', $revision_id);
       // Verify revision log is the same.
-      $this->assertEqual($loaded->getRevisionLog(), $logs[$delta], format_string('Correct log message found for revision !revision', array(
-        '!revision' => $loaded->getRevisionId(),
+      $this->assertEqual($loaded->getRevisionLog(), $logs[$delta], format_string('Correct log message found for revision @revision', array(
+        '@revision' => $loaded->getRevisionId(),
       )));
     }
 
diff --git a/core/modules/block_content/src/Tests/PageEditTest.php b/core/modules/block_content/src/Tests/PageEditTest.php
index fdd1743..e2ce38f 100644
--- a/core/modules/block_content/src/Tests/PageEditTest.php
+++ b/core/modules/block_content/src/Tests/PageEditTest.php
@@ -64,7 +64,7 @@ public function testPageEdit() {
     // Test deleting the block.
     $this->drupalGet("block/" . $revised_block->id());
     $this->clickLink(t('Delete'));
-    $this->assertText(format_string('Are you sure you want to delete the custom block !label?', array('!label' => $revised_block->label())));
+    $this->assertText(format_string('Are you sure you want to delete the custom block @label?', array('@label' => $revised_block->label())));
   }
 
 }
diff --git a/core/modules/config/src/Tests/ConfigExportImportUITest.php b/core/modules/config/src/Tests/ConfigExportImportUITest.php
index 6a63df7..e913e0d 100644
--- a/core/modules/config/src/Tests/ConfigExportImportUITest.php
+++ b/core/modules/config/src/Tests/ConfigExportImportUITest.php
@@ -273,8 +273,8 @@ public function testExportImportCollections() {
     // Verify that there are configuration differences to import.
     $this->drupalGet('admin/config/development/configuration');
     $this->assertNoText(t('There are no configuration changes to import.'));
-    $this->assertText(t('!collection configuration collection', array('!collection' => 'collection.test1')));
-    $this->assertText(t('!collection configuration collection', array('!collection' => 'collection.test2')));
+    $this->assertText(t('@collection configuration collection', array('@collection' => 'collection.test1')));
+    $this->assertText(t('@collection configuration collection', array('@collection' => 'collection.test2')));
     $this->assertText('config_test.create');
     $this->assertLinkByHref('admin/config/development/configuration/sync/diff_collection/collection.test1/config_test.create');
     $this->assertText('config_test.update');
diff --git a/core/modules/config_translation/src/Tests/ConfigTranslationOverviewTest.php b/core/modules/config_translation/src/Tests/ConfigTranslationOverviewTest.php
index eb5cf75..687da5b 100644
--- a/core/modules/config_translation/src/Tests/ConfigTranslationOverviewTest.php
+++ b/core/modules/config_translation/src/Tests/ConfigTranslationOverviewTest.php
@@ -116,7 +116,7 @@ public function testMapperListPage() {
       $entity_type = \Drupal::entityManager()->getDefinition($test_entity->getEntityTypeId());
       $this->drupalGet($base_url . '/translate');
 
-      $title = t('!label !entity_type', array('!label' => $test_entity->label(), '!entity_type' => $entity_type->getLowercaseLabel()));
+      $title = t('@label @entity_type', array('@label' => $test_entity->label(), '@entity_type' => $entity_type->getLowercaseLabel()));
       $title = t('Translations for %label', array('%label' => $title));
       $this->assertRaw($title);
       $this->assertRaw('<th>' . t('Language') . '</th>');
diff --git a/core/modules/config_translation/src/Tests/ConfigTranslationUiTest.php b/core/modules/config_translation/src/Tests/ConfigTranslationUiTest.php
index 2b092a1..13890c0 100644
--- a/core/modules/config_translation/src/Tests/ConfigTranslationUiTest.php
+++ b/core/modules/config_translation/src/Tests/ConfigTranslationUiTest.php
@@ -370,7 +370,7 @@ public function testContactConfigEntityTranslation() {
 
     // Test that delete links work and operations perform properly.
     foreach ($this->langcodes as $langcode) {
-      $replacements = array('%label' => t('!label !entity_type', array('!label' => $label, '!entity_type' => Unicode::strtolower(t('Contact form')))), '@language' => \Drupal::languageManager()->getLanguage($langcode)->getName());
+      $replacements = array('%label' => t('@label @entity_type', array('@label' => $label, '@entity_type' => Unicode::strtolower(t('Contact form')))), '@language' => \Drupal::languageManager()->getLanguage($langcode)->getName());
 
       $this->drupalGet("$translation_base_url/$langcode/delete");
       $this->assertRaw(t('Are you sure you want to delete the @language translation of %label?', $replacements));
diff --git a/core/modules/contact/src/Tests/ContactSitewideTest.php b/core/modules/contact/src/Tests/ContactSitewideTest.php
index 83f296f..651c283 100644
--- a/core/modules/contact/src/Tests/ContactSitewideTest.php
+++ b/core/modules/contact/src/Tests/ContactSitewideTest.php
@@ -129,7 +129,7 @@ function testSiteWideContact() {
     $max_length = EntityTypeInterface::BUNDLE_MAX_LENGTH;
     $max_length_exceeded = $max_length + 1;
     $this->addContactForm($id = Unicode::strtolower($this->randomMachineName($max_length_exceeded)), $label = $this->randomMachineName($max_length_exceeded), implode(',', array($recipients[0])), '', TRUE);
-    $this->assertText(format_string('Machine-readable name cannot be longer than !max characters but is currently !exceeded characters long.', array('!max' => $max_length, '!exceeded' => $max_length_exceeded)));
+    $this->assertText(format_string('Machine-readable name cannot be longer than @max characters but is currently @exceeded characters long.', array('@max' => $max_length, '@exceeded' => $max_length_exceeded)));
     $this->addContactForm($id = Unicode::strtolower($this->randomMachineName($max_length)), $label = $this->randomMachineName($max_length), implode(',', array($recipients[0])), '', TRUE);
     $this->assertRaw(t('Contact form %label has been added.', array('%label' => $label)));
 
diff --git a/core/modules/field/src/Tests/FormTest.php b/core/modules/field/src/Tests/FormTest.php
index ab949eb..0ae049b 100644
--- a/core/modules/field/src/Tests/FormTest.php
+++ b/core/modules/field/src/Tests/FormTest.php
@@ -208,7 +208,7 @@ function testFieldFormSingleRequired() {
     // Submit with missing required value.
     $edit = array();
     $this->drupalPostForm('entity_test/add', $edit, t('Save'));
-    $this->assertRaw(t('!name field is required.', array('!name' => $this->field['label'])), 'Required field with no value fails validation');
+    $this->assertRaw(t('@name field is required.', array('@name' => $this->field['label'])), 'Required field with no value fails validation');
 
     // Create an entity
     $value = mt_rand(1, 127);
@@ -228,7 +228,7 @@ function testFieldFormSingleRequired() {
       "{$field_name}[0][value]" => $value,
     );
     $this->drupalPostForm('entity_test/manage/' . $id, $edit, t('Save'));
-    $this->assertRaw(t('!name field is required.', array('!name' => $this->field['label'])), 'Required field with no value fails validation');
+    $this->assertRaw(t('@name field is required.', array('@name' => $this->field['label'])), 'Required field with no value fails validation');
   }
 
 //  function testFieldFormMultiple() {
diff --git a/core/modules/field/src/Tests/String/StringFieldTest.php b/core/modules/field/src/Tests/String/StringFieldTest.php
index 40cf424..f59d507 100644
--- a/core/modules/field/src/Tests/String/StringFieldTest.php
+++ b/core/modules/field/src/Tests/String/StringFieldTest.php
@@ -81,7 +81,7 @@ function _testTextfieldWidgets($field_type, $widget_type) {
     $this->drupalGet('entity_test/add');
     $this->assertFieldByName("{$field_name}[0][value]", '', 'Widget is displayed');
     $this->assertNoFieldByName("{$field_name}[0][format]", '1', 'Format selector is not displayed');
-    $this->assertRaw(format_string('placeholder="A placeholder on !widget_type"', array('!widget_type' => $widget_type)));
+    $this->assertRaw(format_string('placeholder="A placeholder on @widget_type"', array('@widget_type' => $widget_type)));
 
     // Submit with some value.
     $value = $this->randomMachineName();
diff --git a/core/modules/file/src/Tests/SaveUploadTest.php b/core/modules/file/src/Tests/SaveUploadTest.php
index baeb443..7c3bd4c 100644
--- a/core/modules/file/src/Tests/SaveUploadTest.php
+++ b/core/modules/file/src/Tests/SaveUploadTest.php
@@ -220,7 +220,7 @@ function testHandleDangerousFile() {
     $this->drupalPostForm('file-test/upload', $edit, t('Submit'));
     $this->assertResponse(200, 'Received a 200 response for posted test file.');
     $this->assertNoRaw(t('For security reasons, your upload has been renamed'), 'Found no security message.');
-    $this->assertRaw(t('File name is !filename', array('!filename' => $this->phpfile->filename)), 'Dangerous file was not renamed when insecure uploads is TRUE.');
+    $this->assertRaw(t('File name is @filename', array('@filename' => $this->phpfile->filename)), 'Dangerous file was not renamed when insecure uploads is TRUE.');
     $this->assertRaw(t('You WIN!'), 'Found the success message.');
 
     // Check that the correct hooks were called.
@@ -254,7 +254,7 @@ function testHandleFileMunge() {
     $this->drupalPostForm('file-test/upload', $edit, t('Submit'));
     $this->assertResponse(200, 'Received a 200 response for posted test file.');
     $this->assertRaw(t('For security reasons, your upload has been renamed'), 'Found security message.');
-    $this->assertRaw(t('File name is !filename', array('!filename' => $munged_filename)), 'File was successfully munged.');
+    $this->assertRaw(t('File name is @filename', array('@filename' => $munged_filename)), 'File was successfully munged.');
     $this->assertRaw(t('You WIN!'), 'Found the success message.');
 
     // Check that the correct hooks were called.
@@ -272,7 +272,7 @@ function testHandleFileMunge() {
     $this->drupalPostForm('file-test/upload', $edit, t('Submit'));
     $this->assertResponse(200, 'Received a 200 response for posted test file.');
     $this->assertNoRaw(t('For security reasons, your upload has been renamed'), 'Found no security message.');
-    $this->assertRaw(t('File name is !filename', array('!filename' => $this->image->getFilename())), 'File was not munged when allowing any extension.');
+    $this->assertRaw(t('File name is @filename', array('@filename' => $this->image->getFilename())), 'File was not munged when allowing any extension.');
     $this->assertRaw(t('You WIN!'), 'Found the success message.');
 
     // Check that the correct hooks were called.
diff --git a/core/modules/filter/src/Tests/FilterFormatAccessTest.php b/core/modules/filter/src/Tests/FilterFormatAccessTest.php
index b9eeaa7..441be0d 100644
--- a/core/modules/filter/src/Tests/FilterFormatAccessTest.php
+++ b/core/modules/filter/src/Tests/FilterFormatAccessTest.php
@@ -280,7 +280,7 @@ function testFormatWidgetPermissions() {
     $edit = array();
     $edit['title[0][value]'] = $new_title;
     $this->drupalPostForm('node/' . $node->id() . '/edit', $edit, t('Save'));
-    $this->assertText(t('!name field is required.', array('!name' => t('Text format'))), 'Error message is displayed.');
+    $this->assertText(t('@name field is required.', array('@name' => t('Text format'))), 'Error message is displayed.');
     $this->drupalGet('node/' . $node->id());
     $this->assertText($old_title, 'Old title found.');
     $this->assertNoText($new_title, 'New title not found.');
@@ -315,7 +315,7 @@ function testFormatWidgetPermissions() {
     $edit = array();
     $edit['title[0][value]'] = $new_title;
     $this->drupalPostForm('node/' . $node->id() . '/edit', $edit, t('Save'));
-    $this->assertText(t('!name field is required.', array('!name' => t('Text format'))), 'Error message is displayed.');
+    $this->assertText(t('@name field is required.', array('@name' => t('Text format'))), 'Error message is displayed.');
     $this->drupalGet('node/' . $node->id());
     $this->assertText($old_title, 'Old title found.');
     $this->assertNoText($new_title, 'New title not found.');
diff --git a/core/modules/language/src/Tests/LanguageCustomLanguageConfigurationTest.php b/core/modules/language/src/Tests/LanguageCustomLanguageConfigurationTest.php
index 0927c2d..1a093c2 100644
--- a/core/modules/language/src/Tests/LanguageCustomLanguageConfigurationTest.php
+++ b/core/modules/language/src/Tests/LanguageCustomLanguageConfigurationTest.php
@@ -40,8 +40,8 @@ public function testLanguageConfiguration() {
     );
     $this->drupalPostForm('admin/config/regional/language/add', $edit, t('Add custom language'));
     // Test validation on missing values.
-    $this->assertText(t('!name field is required.', array('!name' => t('Language code'))));
-    $this->assertText(t('!name field is required.', array('!name' => t('Language name'))));
+    $this->assertText(t('@name field is required.', array('@name' => t('Language code'))));
+    $this->assertText(t('@name field is required.', array('@name' => t('Language name'))));
     $empty_language = new Language();
     $this->assertFieldChecked('edit-direction-' . $empty_language->getDirection(), 'Consistent usage of language direction.');
     $this->assertUrl(\Drupal::url('language.add', array(), array('absolute' => TRUE)), [], 'Correct page redirection.');
diff --git a/core/modules/link/src/Tests/LinkFieldTest.php b/core/modules/link/src/Tests/LinkFieldTest.php
index b39a2f5..8247b60 100644
--- a/core/modules/link/src/Tests/LinkFieldTest.php
+++ b/core/modules/link/src/Tests/LinkFieldTest.php
@@ -277,14 +277,14 @@ function testLinkTitle() {
             "{$field_name}[0][uri]" => 'http://www.example.com',
           );
           $this->drupalPostForm(NULL, $edit, t('Save'));
-          $this->assertText(t('!name field is required.', array('!name' => t('Link text'))));
+          $this->assertText(t('@name field is required.', array('@name' => t('Link text'))));
 
           // Verify that the link text is not required, if the URL is empty.
           $edit = array(
             "{$field_name}[0][uri]" => '',
           );
           $this->drupalPostForm(NULL, $edit, t('Save'));
-          $this->assertNoText(t('!name field is required.', array('!name' => t('Link text'))));
+          $this->assertNoText(t('@name field is required.', array('@name' => t('Link text'))));
 
           // Verify that a URL and link text meets requirements.
           $this->drupalGet('entity_test/add');
@@ -293,7 +293,7 @@ function testLinkTitle() {
             "{$field_name}[0][title]" => 'Example',
           );
           $this->drupalPostForm(NULL, $edit, t('Save'));
-          $this->assertNoText(t('!name field is required.', array('!name' => t('Link text'))));
+          $this->assertNoText(t('@name field is required.', array('@name' => t('Link text'))));
         }
       }
     }
diff --git a/core/modules/locale/src/Tests/LocaleUpdateInterfaceTest.php b/core/modules/locale/src/Tests/LocaleUpdateInterfaceTest.php
index dcade86..ad49550 100644
--- a/core/modules/locale/src/Tests/LocaleUpdateInterfaceTest.php
+++ b/core/modules/locale/src/Tests/LocaleUpdateInterfaceTest.php
@@ -111,7 +111,7 @@ public function testInterface() {
 
     // Check if translations are available for Drupal core.
     $this->drupalGet('admin/reports/translations');
-    $this->assertText(t('Updates for: !project', array('!project' => t('Drupal core'))), 'Translations found');
+    $this->assertText(t('Updates for: @project', array('@project' => t('Drupal core'))), 'Translations found');
     $this->assertText(SafeMarkup::format('@module (@date)', array('@module' => t('Drupal core'), '@date' => format_date(REQUEST_TIME, 'html_date'))), 'Core translation update');
     $update_button = $this->xpath('//input[@type="submit"][@value="' . t('Update translations') . '"]');
     $this->assertTrue($update_button, 'Update translations button');
diff --git a/core/modules/menu_ui/src/Tests/MenuTest.php b/core/modules/menu_ui/src/Tests/MenuTest.php
index 128d507..e87cd86 100644
--- a/core/modules/menu_ui/src/Tests/MenuTest.php
+++ b/core/modules/menu_ui/src/Tests/MenuTest.php
@@ -195,8 +195,8 @@ function addCustomMenu() {
 
     // Verify that using a menu_name that is too long results in a validation
     // message.
-    $this->assertRaw(t('!name cannot be longer than %max characters but is currently %length characters long.', array(
-      '!name' => t('Menu name'),
+    $this->assertRaw(t('@name cannot be longer than %max characters but is currently %length characters long.', array(
+      '@name' => t('Menu name'),
       '%max' => MENU_MAX_MENU_NAME_LENGTH_UI,
       '%length' => Unicode::strlen($menu_name),
     )));
@@ -207,8 +207,8 @@ function addCustomMenu() {
     $this->drupalPostForm('admin/structure/menu/add', $edit, t('Save'));
 
     // Verify that no validation error is given for menu_name length.
-    $this->assertNoRaw(t('!name cannot be longer than %max characters but is currently %length characters long.', array(
-      '!name' => t('Menu name'),
+    $this->assertNoRaw(t('@name cannot be longer than %max characters but is currently %length characters long.', array(
+      '@name' => t('Menu name'),
       '%max' => MENU_MAX_MENU_NAME_LENGTH_UI,
       '%length' => Unicode::strlen($menu_name),
     )));
diff --git a/core/modules/node/src/Tests/NodeCreationTest.php b/core/modules/node/src/Tests/NodeCreationTest.php
index 7972f5d..abe7ba7 100644
--- a/core/modules/node/src/Tests/NodeCreationTest.php
+++ b/core/modules/node/src/Tests/NodeCreationTest.php
@@ -52,7 +52,7 @@ function testNodeCreation() {
     $this->drupalPostForm('node/add/page', $edit, t('Save'));
 
     // Check that the Basic page has been created.
-    $this->assertRaw(t('!post %title has been created.', array('!post' => 'Basic page', '%title' => $edit['title[0][value]'])), 'Basic page created.');
+    $this->assertRaw(t('@post %title has been created.', array('@post' => 'Basic page', '%title' => $edit['title[0][value]'])), 'Basic page created.');
 
     // Check that the node exists in the database.
     $node = $this->drupalGetNodeByTitle($edit['title[0][value]']);
@@ -141,7 +141,7 @@ function testUnpublishedNodeCreation() {
     $this->assertText(t('Test page text'));
 
     // Confirm that the node was created.
-    $this->assertRaw(t('!post %title has been created.', array('!post' => 'Basic page', '%title' => $edit['title[0][value]'])));
+    $this->assertRaw(t('@post %title has been created.', array('@post' => 'Basic page', '%title' => $edit['title[0][value]'])));
   }
 
   /**
diff --git a/core/modules/node/src/Tests/NodeRSSContentTest.php b/core/modules/node/src/Tests/NodeRSSContentTest.php
index 4b63eea..144e36e 100644
--- a/core/modules/node/src/Tests/NodeRSSContentTest.php
+++ b/core/modules/node/src/Tests/NodeRSSContentTest.php
@@ -45,16 +45,16 @@ function testNodeRSSContent() {
     $this->drupalGet('rss.xml');
 
     // Check that content added in 'rss' view mode appear in RSS feed.
-    $rss_only_content = t('Extra data that should appear only in the RSS feed for node !nid.', array('!nid' => $node->id()));
+    $rss_only_content = t('Extra data that should appear only in the RSS feed for node @nid.', array('@nid' => $node->id()));
     $this->assertText($rss_only_content, 'Node content designated for RSS appear in RSS feed.');
 
     // Check that content added in view modes other than 'rss' doesn't
     // appear in RSS feed.
-    $non_rss_content = t('Extra data that should appear everywhere except the RSS feed for node !nid.', array('!nid' => $node->id()));
+    $non_rss_content = t('Extra data that should appear everywhere except the RSS feed for node @nid.', array('@nid' => $node->id()));
     $this->assertNoText($non_rss_content, 'Node content not designed for RSS does not appear in RSS feed.');
 
     // Check that extra RSS elements and namespaces are added to RSS feed.
-    $test_element = '<testElement>' . t('Value of testElement RSS element for node !nid.', array('!nid' => $node->id())) . '</testElement>';
+    $test_element = '<testElement>' . t('Value of testElement RSS element for node @nid.', array('@nid' => $node->id())) . '</testElement>';
     $test_ns = 'xmlns:drupaltest="http://example.com/test-namespace"';
     $this->assertRaw($test_element, 'Extra RSS elements appear in RSS feed.');
     $this->assertRaw($test_ns, 'Extra namespaces appear in RSS feed.');
diff --git a/core/modules/node/src/Tests/NodeRevisionsUiTest.php b/core/modules/node/src/Tests/NodeRevisionsUiTest.php
index adc49bf..1112847 100644
--- a/core/modules/node/src/Tests/NodeRevisionsUiTest.php
+++ b/core/modules/node/src/Tests/NodeRevisionsUiTest.php
@@ -119,17 +119,17 @@ public function testNodeRevisionDoubleEscapeFix() {
     // Assert the old revision message.
     $date = format_date($nodes[0]->revision_timestamp->value, 'short');
     $url = new Url('entity.node.revision', ['node' => $nodes[0]->id(), 'node_revision' => $nodes[0]->getRevisionId()]);
-    $old_revision_message = t('!date by !username', [
-      '!date' => \Drupal::l($date, $url),
-      '!username' => $editor,
+    $old_revision_message = t('@date by @username', [
+      '@date' => \Drupal::l($date, $url),
+      '@username' => $editor,
     ]);
     $this->assertRaw($old_revision_message);
 
     // Assert the current revision message.
     $date = format_date($nodes[1]->revision_timestamp->value, 'short');
-    $current_revision_message = t('!date by !username', [
-      '!date' => $nodes[1]->link($date),
-      '!username' => $editor,
+    $current_revision_message = t('@date by @username', [
+      '@date' => $nodes[1]->link($date),
+      '@username' => $editor,
     ]);
     $current_revision_message .= '<p class="revision-log">' . $revision_log . '</p>';
     $this->assertRaw($current_revision_message);
diff --git a/core/modules/node/tests/modules/node_test/node_test.module b/core/modules/node/tests/modules/node_test/node_test.module
index 7f2cd53..b78e489 100644
--- a/core/modules/node/tests/modules/node_test/node_test.module
+++ b/core/modules/node/tests/modules/node_test/node_test.module
@@ -20,12 +20,12 @@ function node_test_node_view(array &$build, NodeInterface $node, EntityViewDispl
     // Add RSS elements and namespaces when building the RSS feed.
     $node->rss_elements[] = array(
       'key' => 'testElement',
-      'value' => t('Value of testElement RSS element for node !nid.', array('!nid' => $node->id())),
+      'value' => t('Value of testElement RSS element for node @nid.', array('@nid' => $node->id())),
     );
 
     // Add content that should be displayed only in the RSS feed.
     $build['extra_feed_content'] = array(
-      '#markup' => '<p>' . t('Extra data that should appear only in the RSS feed for node !nid.', array('!nid' => $node->id())) . '</p>',
+      '#markup' => '<p>' . t('Extra data that should appear only in the RSS feed for node @nid.', array('@nid' => $node->id())) . '</p>',
       '#weight' => 10,
     );
   }
@@ -33,7 +33,7 @@ function node_test_node_view(array &$build, NodeInterface $node, EntityViewDispl
   if ($view_mode != 'rss') {
     // Add content that should NOT be displayed in the RSS feed.
     $build['extra_non_feed_content'] = array(
-      '#markup' => '<p>' . t('Extra data that should appear everywhere except the RSS feed for node !nid.', array('!nid' => $node->id())) . '</p>',
+      '#markup' => '<p>' . t('Extra data that should appear everywhere except the RSS feed for node @nid.', array('@nid' => $node->id())) . '</p>',
     );
   }
 }
diff --git a/core/modules/options/src/Tests/OptionsFieldUITest.php b/core/modules/options/src/Tests/OptionsFieldUITest.php
index c0ab0df..d4219c6 100644
--- a/core/modules/options/src/Tests/OptionsFieldUITest.php
+++ b/core/modules/options/src/Tests/OptionsFieldUITest.php
@@ -326,7 +326,7 @@ function testNodeDisplay() {
     );
 
     $this->drupalPostForm($this->adminPath, $edit, t('Save field settings'));
-    $this->assertText(format_string('Updated field !field_name field settings.', array('!field_name' => $this->fieldName)), "The 'On' and 'Off' form fields work for boolean fields.");
+    $this->assertText(format_string('Updated field @field_name field settings.', array('@field_name' => $this->fieldName)), "The 'On' and 'Off' form fields work for boolean fields.");
 
     // Select a default value.
     $edit = array(
diff --git a/core/modules/options/src/Tests/OptionsWidgetsTest.php b/core/modules/options/src/Tests/OptionsWidgetsTest.php
index 6bd4714..f1d2ca3 100644
--- a/core/modules/options/src/Tests/OptionsWidgetsTest.php
+++ b/core/modules/options/src/Tests/OptionsWidgetsTest.php
@@ -269,7 +269,7 @@ function testSelectListSingle() {
     // Submit form: select invalid 'none' option.
     $edit = array('card_1' => '_none');
     $this->drupalPostForm(NULL, $edit, t('Save'));
-    $this->assertRaw(t('!title field is required.', array('!title' => $field->getName())), 'Cannot save a required field when selecting "none" from the select list.');
+    $this->assertRaw(t('@title field is required.', array('@title' => $field->getName())), 'Cannot save a required field when selecting "none" from the select list.');
 
     // Submit form: select first option.
     $edit = array('card_1' => 0);
diff --git a/core/modules/system/src/Tests/Element/PathElementFormTest.php b/core/modules/system/src/Tests/Element/PathElementFormTest.php
index 5698951..bcbe534 100644
--- a/core/modules/system/src/Tests/Element/PathElementFormTest.php
+++ b/core/modules/system/src/Tests/Element/PathElementFormTest.php
@@ -184,7 +184,7 @@ public function testPathElement() {
     $errors = $form_state->getErrors();
     // Should be missing 'required_validate' field.
     $this->assertEqual(count($errors), 1);
-    $this->assertEqual($errors, array('required_validate' => t('!name field is required.', array('!name' => 'required_validate'))));
+    $this->assertEqual($errors, array('required_validate' => t('@name field is required.', array('@name' => 'required_validate'))));
 
     // Test invalid parameters.
     $form_state = (new FormState())
diff --git a/core/modules/system/src/Tests/Form/EmailTest.php b/core/modules/system/src/Tests/Form/EmailTest.php
index 69e9807..f409b46 100644
--- a/core/modules/system/src/Tests/Form/EmailTest.php
+++ b/core/modules/system/src/Tests/Form/EmailTest.php
@@ -35,7 +35,7 @@ function testFormEmail() {
     $edit['email_required'] = ' ';
     $this->drupalPostForm('form-test/email', $edit, 'Submit');
     $this->assertRaw(t('The email address %mail is not valid.', array('%mail' => 'invalid')));
-    $this->assertRaw(t('!name field is required.', array('!name' => 'Address')));
+    $this->assertRaw(t('@name field is required.', array('@name' => 'Address')));
 
     $edit = array();
     $edit['email_required'] = '  foo.bar@example.com ';
diff --git a/core/modules/system/src/Tests/Form/FormTest.php b/core/modules/system/src/Tests/Form/FormTest.php
index e89b78f..d3d1826 100644
--- a/core/modules/system/src/Tests/Form/FormTest.php
+++ b/core/modules/system/src/Tests/Form/FormTest.php
@@ -185,7 +185,7 @@ function testRequiredCheckboxesRadio() {
         $expected[] = $form[$key]['#form_test_required_error'];
       }
       else {
-        $expected[] = t('!name field is required.', array('!name' => $form[$key]['#title']));
+        $expected[] = t('@name field is required.', array('@name' => $form[$key]['#title']));
       }
     }
 
@@ -335,7 +335,7 @@ function testCheckboxProcessing() {
     // First, try to submit without the required checkbox.
     $edit = array();
     $this->drupalPostForm('form-test/checkbox', $edit, t('Submit'));
-    $this->assertRaw(t('!name field is required.', array('!name' => 'required_checkbox')), 'A required checkbox is actually mandatory');
+    $this->assertRaw(t('@name field is required.', array('@name' => 'required_checkbox')), 'A required checkbox is actually mandatory');
 
     // Now try to submit the form correctly.
     $values = Json::decode($this->drupalPostForm(NULL, array('required_checkbox' => 1), t('Submit')));
@@ -361,7 +361,6 @@ function testCheckboxProcessing() {
    */
   function testSelect() {
     $form = \Drupal::formBuilder()->getForm('Drupal\form_test\Form\FormTestSelectForm');
-    $error = '!name field is required.';
     $this->drupalGet('form-test/select');
 
     // Posting without any values should throw validation errors.
@@ -379,7 +378,7 @@ function testSelect() {
         'multiple_no_default',
     );
     foreach ($no_errors as $key) {
-      $this->assertNoText(t('!name field is required.', array('!name' => $form[$key]['#title'])));
+      $this->assertNoText(t('@name field is required.', array('@name' => $form[$key]['#title'])));
     }
 
     $expected_errors = array(
@@ -390,7 +389,7 @@ function testSelect() {
         'multiple_no_default_required',
     );
     foreach ($expected_errors as $key) {
-      $this->assertText(t('!name field is required.', array('!name' => $form[$key]['#title'])));
+      $this->assertText(t('@name field is required.', array('@name' => $form[$key]['#title'])));
     }
 
     // Post values for required fields.
diff --git a/core/modules/system/src/Tests/Form/UrlTest.php b/core/modules/system/src/Tests/Form/UrlTest.php
index 494255d..67d7a41 100644
--- a/core/modules/system/src/Tests/Form/UrlTest.php
+++ b/core/modules/system/src/Tests/Form/UrlTest.php
@@ -35,7 +35,7 @@ function testFormUrl() {
     $edit['url_required'] = ' ';
     $this->drupalPostForm('form-test/url', $edit, 'Submit');
     $this->assertRaw(t('The URL %url is not valid.', array('%url' => 'http://')));
-    $this->assertRaw(t('!name field is required.', array('!name' => 'Required URL')));
+    $this->assertRaw(t('@name field is required.', array('@name' => 'Required URL')));
 
     $edit = array();
     $edit['url'] = "\n";
diff --git a/core/modules/system/src/Tests/Form/ValidationTest.php b/core/modules/system/src/Tests/Form/ValidationTest.php
index 74e9583..2bc4867 100644
--- a/core/modules/system/src/Tests/Form/ValidationTest.php
+++ b/core/modules/system/src/Tests/Form/ValidationTest.php
@@ -118,19 +118,19 @@ function testValidateLimitErrors() {
     // validated, but the #element_validate handler for the 'test' field
     // is triggered.
     $this->drupalPostForm($path, $edit, t('Partial validate'));
-    $this->assertNoText(t('!name field is required.', array('!name' => 'Title')));
+    $this->assertNoText(t('@name field is required.', array('@name' => 'Title')));
     $this->assertText('Test element is invalid');
 
     // Edge case of #limit_validation_errors containing numeric indexes: same
     // thing with the 'Partial validate (numeric index)' button and the
     // 'test_numeric_index' field.
     $this->drupalPostForm($path, $edit, t('Partial validate (numeric index)'));
-    $this->assertNoText(t('!name field is required.', array('!name' => 'Title')));
+    $this->assertNoText(t('@name field is required.', array('@name' => 'Title')));
     $this->assertText('Test (numeric index) element is invalid');
 
     // Ensure something like 'foobar' isn't considered "inside" 'foo'.
     $this->drupalPostForm($path, $edit, t('Partial validate (substring)'));
-    $this->assertNoText(t('!name field is required.', array('!name' => 'Title')));
+    $this->assertNoText(t('@name field is required.', array('@name' => 'Title')));
     $this->assertText('Test (substring) foo element is invalid');
 
     // Ensure not validated values are not available to submit handlers.
@@ -140,7 +140,7 @@ function testValidateLimitErrors() {
     // Now test full form validation and ensure that the #element_validate
     // handler is still triggered.
     $this->drupalPostForm($path, $edit, t('Full validate'));
-    $this->assertText(t('!name field is required.', array('!name' => 'Title')));
+    $this->assertText(t('@name field is required.', array('@name' => 'Title')));
     $this->assertText('Test element is invalid');
   }
 
@@ -218,7 +218,7 @@ function testCustomRequiredError() {
     $messages = [];
     foreach (Element::children($form) as $key) {
       if (isset($form[$key]['#required_error'])) {
-        $this->assertNoText(t('!name field is required.', array('!name' => $form[$key]['#title'])));
+        $this->assertNoText(t('@name field is required.', array('@name' => $form[$key]['#title'])));
         $messages[] = [
           'title' => $form[$key]['#title'],
           'message' => $form[$key]['#required_error'],
@@ -226,7 +226,7 @@ function testCustomRequiredError() {
         ];
       }
       elseif (isset($form[$key]['#form_test_required_error'])) {
-        $this->assertNoText(t('!name field is required.', array('!name' => $form[$key]['#title'])));
+        $this->assertNoText(t('@name field is required.', array('@name' => $form[$key]['#title'])));
         $messages[] = [
           'title' => $form[$key]['#title'],
           'message' => $form[$key]['#form_test_required_error'],
@@ -236,7 +236,7 @@ function testCustomRequiredError() {
       elseif (!empty($form[$key]['#required'])) {
         $messages[] = [
           'title' => $form[$key]['#title'],
-          'message' => t('!name field is required.', ['!name' => $form[$key]['#title']]),
+          'message' => t('@name field is required.', ['@name' => $form[$key]['#title']]),
           'key' => $key,
         ];
       }
@@ -254,17 +254,17 @@ function testCustomRequiredError() {
     $messages = [];
     foreach (Element::children($form) as $key) {
       if (isset($form[$key]['#required_error'])) {
-        $this->assertNoText(t('!name field is required.', array('!name' => $form[$key]['#title'])));
+        $this->assertNoText(t('@name field is required.', array('@name' => $form[$key]['#title'])));
         $this->assertNoText($form[$key]['#required_error']);
       }
       elseif (isset($form[$key]['#form_test_required_error'])) {
-        $this->assertNoText(t('!name field is required.', array('!name' => $form[$key]['#title'])));
+        $this->assertNoText(t('@name field is required.', array('@name' => $form[$key]['#title'])));
         $this->assertNoText($form[$key]['#form_test_required_error']);
       }
       elseif (!empty($form[$key]['#required'])) {
         $messages[] = [
           'title' => $form[$key]['#title'],
-          'message' => t('!name field is required.', ['!name' => $form[$key]['#title']]),
+          'message' => t('@name field is required.', ['@name' => $form[$key]['#title']]),
           'key' => $key,
         ];
       }
diff --git a/core/modules/system/src/Tests/Theme/ThemeTest.php b/core/modules/system/src/Tests/Theme/ThemeTest.php
index bab41ad..4aafc4f 100644
--- a/core/modules/system/src/Tests/Theme/ThemeTest.php
+++ b/core/modules/system/src/Tests/Theme/ThemeTest.php
@@ -66,7 +66,7 @@ function testThemeDataTypes() {
     $foos = array('null' => NULL, 'false' => FALSE, 'integer' => 1, 'string' => 'foo', 'empty_string' => '');
     foreach ($foos as $type => $example) {
       $output = \Drupal::theme()->render('theme_test_foo', array('foo' => $example));
-      $this->assertTrue($output instanceof SafeStringInterface || is_string($output), format_string('\Drupal::theme() returns an object that implements SafeStringInterface or a string for data type !type.', array('!type' => $type)));
+      $this->assertTrue($output instanceof SafeStringInterface || is_string($output), format_string('\Drupal::theme() returns an object that implements SafeStringInterface or a string for data type @type.', array('@type' => $type)));
       if ($output instanceof SafeStringInterface) {
         $this->assertIdentical((string) $example, $output->__toString());
       }
diff --git a/core/modules/system/tests/modules/form_test/src/Form/FormTestVerticalTabsForm.php b/core/modules/system/tests/modules/form_test/src/Form/FormTestVerticalTabsForm.php
index 2c47068..a2bac03 100644
--- a/core/modules/system/tests/modules/form_test/src/Form/FormTestVerticalTabsForm.php
+++ b/core/modules/system/tests/modules/form_test/src/Form/FormTestVerticalTabsForm.php
@@ -33,12 +33,12 @@ public function buildForm(array $form, FormStateInterface $form_state) {
     for ($i = 1; $i <= $tab_count; $i++) {
       $form['tab' . $i] = array(
         '#type' => 'fieldset',
-        '#title' => t('Tab !num', array('!num' => $i)),
+        '#title' => t('Tab @num', array('@num' => $i)),
         '#group' => 'vertical_tabs',
         '#access' => \Drupal::currentUser()->hasPermission('access vertical_tab_test tabs'),
       );
       $form['tab' . $i]['field' . $i] = array(
-        '#title' => t('Field !num', array('!num' => $i)),
+        '#title' => t('Field @num', array('@num' => $i)),
         '#type' => 'textfield',
 
       );
diff --git a/core/modules/taxonomy/src/Tests/LoadMultipleTest.php b/core/modules/taxonomy/src/Tests/LoadMultipleTest.php
index f824792..5bdba22 100644
--- a/core/modules/taxonomy/src/Tests/LoadMultipleTest.php
+++ b/core/modules/taxonomy/src/Tests/LoadMultipleTest.php
@@ -38,7 +38,7 @@ function testTaxonomyTermMultipleLoad() {
     // Load the terms from the vocabulary.
     $terms = entity_load_multiple_by_properties('taxonomy_term', array('vid' => $vocabulary->id()));
     $count = count($terms);
-    $this->assertEqual($count, 5, format_string('Correct number of terms were loaded. !count terms.', array('!count' => $count)));
+    $this->assertEqual($count, 5, format_string('Correct number of terms were loaded. @count terms.', array('@count' => $count)));
 
     // Load the same terms again by tid.
     $terms2 = Term::loadMultiple(array_keys($terms));
diff --git a/core/modules/user/src/Tests/UserRolesAssignmentTest.php b/core/modules/user/src/Tests/UserRolesAssignmentTest.php
index fc074c8..60f4eab 100644
--- a/core/modules/user/src/Tests/UserRolesAssignmentTest.php
+++ b/core/modules/user/src/Tests/UserRolesAssignmentTest.php
@@ -58,7 +58,7 @@ function testCreateUserWithRole() {
       "roles[$rid]" => $rid,
     );
     $this->drupalPostForm('admin/people/create', $edit, t('Create new account'));
-    $this->assertText(t('Created a new user account for !name.', array('!name' => $edit['name'])));
+    $this->assertText(t('Created a new user account for @name.', array('@name' => $edit['name'])));
     // Get the newly added user.
     $account = user_load_by_name($edit['name']);
 
diff --git a/core/modules/user/src/Tests/UserValidationTest.php b/core/modules/user/src/Tests/UserValidationTest.php
index f66f465..b419103 100644
--- a/core/modules/user/src/Tests/UserValidationTest.php
+++ b/core/modules/user/src/Tests/UserValidationTest.php
@@ -136,7 +136,7 @@ function testValidation() {
     $violations = $user->validate();
     $this->assertEqual(count($violations), 1, 'E-mail addresses may not be removed');
     $this->assertEqual($violations[0]->getPropertyPath(), 'mail');
-    $this->assertEqual($violations[0]->getMessage(), t('!name field is required.', array('!name' => $user->getFieldDefinition('mail')->getLabel())));
+    $this->assertEqual($violations[0]->getMessage(), t('@name field is required.', array('@name' => $user->getFieldDefinition('mail')->getLabel())));
     $user->set('mail', 'someone@example.com');
 
     $user->set('timezone', $this->randomString(33));
diff --git a/core/modules/views/src/Tests/Handler/FieldKernelTest.php b/core/modules/views/src/Tests/Handler/FieldKernelTest.php
index 7a4e338..cbf65ef 100644
--- a/core/modules/views/src/Tests/Handler/FieldKernelTest.php
+++ b/core/modules/views/src/Tests/Handler/FieldKernelTest.php
@@ -242,25 +242,25 @@ public function testFieldTokens() {
       $output = $renderer->executeInRenderContext(new RenderContext(), function () use ($name_field_0, $row) {
         return $name_field_0->advancedRender($row);
       });
-      $this->assertEqual($output, $expected_output_0, format_string('Test token replacement: "!token" gave "!output"', [
-        '!token' => $name_field_0->options['alter']['text'],
-        '!output' => $output,
+      $this->assertEqual($output, $expected_output_0, format_string('Test token replacement: "@token" gave "@output"', [
+        '@token' => $name_field_0->options['alter']['text'],
+        '@output' => $output,
       ]));
 
       $output = $renderer->executeInRenderContext(new RenderContext(), function () use ($name_field_1, $row) {
         return $name_field_1->advancedRender($row);
       });
-      $this->assertEqual($output, $expected_output_1, format_string('Test token replacement: "!token" gave "!output"', [
-        '!token' => $name_field_1->options['alter']['text'],
-        '!output' => $output,
+      $this->assertEqual($output, $expected_output_1, format_string('Test token replacement: "@token" gave "@output"', [
+        '@token' => $name_field_1->options['alter']['text'],
+        '@output' => $output,
       ]));
 
       $output = $renderer->executeInRenderContext(new RenderContext(), function () use ($name_field_2, $row) {
         return $name_field_2->advancedRender($row);
       });
-      $this->assertEqual($output, $expected_output_2, format_string('Test token replacement: "!token" gave "!output"', [
-        '!token' => $name_field_2->options['alter']['text'],
-        '!output' => $output,
+      $this->assertEqual($output, $expected_output_2, format_string('Test token replacement: "@token" gave "@output"', [
+        '@token' => $name_field_2->options['alter']['text'],
+        '@output' => $output,
       ]));
     }
 
@@ -273,10 +273,10 @@ public function testFieldTokens() {
     $output = $renderer->executeInRenderContext(new RenderContext(), function () use ($job_field, $row) {
       return $job_field->advancedRender($row);
     });
-    $this->assertSubString($output, $random_text, format_string('Make sure the self token (!token => !value) appears in the output (!output)', [
-      '!value' => $random_text,
-      '!output' => $output,
-      '!token' => $job_field->options['alter']['text'],
+    $this->assertSubString($output, $random_text, format_string('Make sure the self token (@token => @value) appears in the output (@output)', [
+      '@value' => $random_text,
+      '@output' => $output,
+      '@token' => $job_field->options['alter']['text'],
     ]));
 
     // Verify the token format used in D7 and earlier does not get substituted.
@@ -287,10 +287,10 @@ public function testFieldTokens() {
     $output = $renderer->executeInRenderContext(new RenderContext(), function () use ($job_field, $row) {
       return $job_field->advancedRender($row);
     });
-    $this->assertEqual($output, $old_token, format_string('Make sure the old token style (!token => !value) is not changed in the output (!output)', [
-      '!value' => $random_text,
-      '!output' => $output,
-      '!token' => $job_field->options['alter']['text'],
+    $this->assertEqual($output, $old_token, format_string('Make sure the old token style (@token => @value) is not changed in the output (@output)', [
+      '@value' => $random_text,
+      '@output' => $output,
+      '@token' => $job_field->options['alter']['text'],
     ]));
 
     // Verify HTML tags are allowed in rewrite templates while token
@@ -320,9 +320,9 @@ public function testFieldTokens() {
     $output = $renderer->executeInRenderContext(new RenderContext(), function () use ($job_field, $row) {
       return $job_field->advancedRender($row);
     });
-    $this->assertEqual($output, $random_text, format_string('Make sure a script tag in the template (!template) is removed, leaving only the replaced token in the output (!output)', [
-      '!output' => $output,
-      '!template' => $rewrite_template,
+    $this->assertEqual($output, $random_text, format_string('Make sure a script tag in the template (@template) is removed, leaving only the replaced token in the output (@output)', [
+      '@output' => $output,
+      '@template' => $rewrite_template,
     ]));
   }
 
diff --git a/core/modules/views/src/Tests/Handler/FieldWebTest.php b/core/modules/views/src/Tests/Handler/FieldWebTest.php
index 0435809..98fe8af 100644
--- a/core/modules/views/src/Tests/Handler/FieldWebTest.php
+++ b/core/modules/views/src/Tests/Handler/FieldWebTest.php
@@ -564,14 +564,14 @@ public function testTextRendering() {
     $output = $renderer->executeInRenderContext(new RenderContext(), function () use ($name_field, $row) {
       return $name_field->advancedRender($row);
     });
-    $this->assertSubString($output, $trimmed_name, format_string('Make sure the trimmed output (!trimmed) appears in the rendered output (!output).', array('!trimmed' => $trimmed_name, '!output' => $output)));
-    $this->assertNotSubString($output, $row->views_test_data_name, format_string("Make sure the untrimmed value (!untrimmed) shouldn't appear in the rendered output (!output).", array('!untrimmed' => $row->views_test_data_name, '!output' => $output)));
+    $this->assertSubString($output, $trimmed_name, format_string('Make sure the trimmed output (@trimmed) appears in the rendered output (@output).', array('@trimmed' => $trimmed_name, '@output' => $output)));
+    $this->assertNotSubString($output, $row->views_test_data_name, format_string("Make sure the untrimmed value (@untrimmed) shouldn't appear in the rendered output (@output).", array('@untrimmed' => $row->views_test_data_name, '@output' => $output)));
 
     $name_field->options['alter']['max_length'] = 9;
     $output = $renderer->executeInRenderContext(new RenderContext(), function () use ($name_field, $row) {
       return $name_field->advancedRender($row);
     });
-    $this->assertSubString($output, $trimmed_name, format_string('Make sure the untrimmed (!untrimmed) output appears in the rendered output  (!output).', array('!trimmed' => $trimmed_name, '!output' => $output)));
+    $this->assertSubString($output, $trimmed_name, format_string('Make sure the untrimmed (@untrimmed) output appears in the rendered output  (@output).', array('@trimmed' => $trimmed_name, '@output' => $output)));
 
     // Take word_boundary into account for the tests.
     $name_field->options['alter']['max_length'] = 5;
@@ -615,10 +615,10 @@ public function testTextRendering() {
       });
 
       if ($tuple['trimmed']) {
-        $this->assertNotSubString($output, $tuple['value'], format_string('The untrimmed value (!untrimmed) should not appear in the trimmed output (!output).', array('!untrimmed' => $tuple['value'], '!output' => $output)));
+        $this->assertNotSubString($output, $tuple['value'], format_string('The untrimmed value (@untrimmed) should not appear in the trimmed output (@output).', array('@untrimmed' => $tuple['value'], '@output' => $output)));
       }
       if (!empty($tuple['trimmed_value'])) {
-        $this->assertSubString($output, $tuple['trimmed_value'], format_string('The trimmed value (!trimmed) should appear in the trimmed output (!output).', array('!trimmed' => $tuple['trimmed_value'], '!output' => $output)));
+        $this->assertSubString($output, $tuple['trimmed_value'], format_string('The trimmed value (@trimmed) should appear in the trimmed output (@output).', array('@trimmed' => $tuple['trimmed_value'], '@output' => $output)));
       }
     }
 
diff --git a/core/modules/views_ui/src/Tests/ViewEditTest.php b/core/modules/views_ui/src/Tests/ViewEditTest.php
index b68dee0..ee5cc60 100644
--- a/core/modules/views_ui/src/Tests/ViewEditTest.php
+++ b/core/modules/views_ui/src/Tests/ViewEditTest.php
@@ -110,7 +110,7 @@ public function testEditFormLanguageOptions() {
       $this->assertResponse(200);
       $langcode_url = 'admin/structure/views/nojs/display/' . $view_name . '/' . $display . '/rendering_language';
       $this->assertNoLinkByHref($langcode_url);
-      $this->assertNoLink(t('!type language selected for page', array('!type' => t('Content'))));
+      $this->assertNoLink(t('@type language selected for page', array('@type' => t('Content'))));
       $this->assertNoLink(t('Content language of view row'));
     }
 
@@ -127,12 +127,12 @@ public function testEditFormLanguageOptions() {
       $langcode_url = 'admin/structure/views/nojs/display/' . $view_name . '/' . $display . '/rendering_language';
       if ($view_name == 'test_view') {
         $this->assertNoLinkByHref($langcode_url);
-        $this->assertNoLink(t('!type language selected for page', array('!type' => t('Content'))));
+        $this->assertNoLink(t('@type language selected for page', array('@type' => t('Content'))));
         $this->assertNoLink(t('Content language of view row'));
       }
       else {
         $this->assertLinkByHref($langcode_url);
-        $this->assertNoLink(t('!type language selected for page', array('!type' => t('Content'))));
+        $this->assertNoLink(t('@type language selected for page', array('@type' => t('Content'))));
         $this->assertLink(t('Content language of view row'));
       }