From e3221b6ddc314669f57d5dc2dfc3aee5388fc56d Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?G=C3=A1bor=20Hojtsy?= <gabor@hojtsy.hu>
Date: Tue, 18 Feb 2020 18:20:22 +0100
Subject: [PATCH] Issue #3096349 by bnjmnm, dww, lauriii: Create test for
 confirming Themes do not depend on Classy templates

(cherry picked from commit 9a5df1707c336b844e7bc3cb3071ab7c4a81f079)
---
 .../content/node--article--full.html.twig     |   2 +-
 .../content/node--card-common.html.twig       |   2 +-
 .../templates/content/node--card.html.twig    |   2 +-
 .../umami/templates/content/node.html.twig    |   2 +-
 .../ThemesNotUsingClassyTemplatesTest.php     | 515 ++++++++++++++++++
 .../block--search-form-block.html.twig        |  45 +-
 .../block--system-menu-block.html.twig        |  69 ++-
 core/themes/bartik/templates/node.html.twig   |   2 +-
 .../bartik/templates/page-title.html.twig     |  14 +-
 .../templates/status-messages.html.twig       |  50 +-
 .../claro/templates/field/file-link.html.twig |   2 +-
 .../templates/form-element-label.html.twig    |  22 +-
 .../seven/templates/image-widget.html.twig    |  19 +-
 13 files changed, 700 insertions(+), 46 deletions(-)
 create mode 100644 core/tests/Drupal/KernelTests/Core/Theme/ThemesNotUsingClassyTemplatesTest.php

diff --git a/core/profiles/demo_umami/themes/umami/templates/content/node--article--full.html.twig b/core/profiles/demo_umami/themes/umami/templates/content/node--article--full.html.twig
index 7cd0fe0f53c..55ae577b323 100644
--- a/core/profiles/demo_umami/themes/umami/templates/content/node--article--full.html.twig
+++ b/core/profiles/demo_umami/themes/umami/templates/content/node--article--full.html.twig
@@ -77,7 +77,7 @@
   ]
 %}
 {% set created_date = node.getCreatedTime|format_date('umami_dates') %}
-{{ attach_library('classy/node') }}
+{{ attach_library('umami/classy.node') }}
 <article{{ attributes.addClass(classes) }}>
 
   {{ title_prefix }}
diff --git a/core/profiles/demo_umami/themes/umami/templates/content/node--card-common.html.twig b/core/profiles/demo_umami/themes/umami/templates/content/node--card-common.html.twig
index 7def0d41d31..00ccfb68b5e 100644
--- a/core/profiles/demo_umami/themes/umami/templates/content/node--card-common.html.twig
+++ b/core/profiles/demo_umami/themes/umami/templates/content/node--card-common.html.twig
@@ -77,7 +77,7 @@
     view_mode ? 'node--view-mode-' ~ view_mode|clean_class,
   ]
 %}
-{{ attach_library('classy/node') }}
+{{ attach_library('umami/classy.node') }}
 {{ attach_library('umami/view-mode-card') }}
 {% block libraries %}
 {{ attach_library('umami/view-mode-card-common') }}
diff --git a/core/profiles/demo_umami/themes/umami/templates/content/node--card.html.twig b/core/profiles/demo_umami/themes/umami/templates/content/node--card.html.twig
index 8a127561549..9835c2e0fe2 100644
--- a/core/profiles/demo_umami/themes/umami/templates/content/node--card.html.twig
+++ b/core/profiles/demo_umami/themes/umami/templates/content/node--card.html.twig
@@ -77,7 +77,7 @@
     view_mode ? 'node--view-mode-' ~ view_mode|clean_class,
   ]
 %}
-{{ attach_library('classy/node') }}
+{{ attach_library('umami/classy.node') }}
 {{ attach_library('umami/view-mode-card') }}
 
 <article{{ attributes.addClass(classes) }}>
diff --git a/core/profiles/demo_umami/themes/umami/templates/content/node.html.twig b/core/profiles/demo_umami/themes/umami/templates/content/node.html.twig
index 359f926dd1f..64122a30249 100644
--- a/core/profiles/demo_umami/themes/umami/templates/content/node.html.twig
+++ b/core/profiles/demo_umami/themes/umami/templates/content/node.html.twig
@@ -77,7 +77,7 @@
   ]
 %}
 {% set created_date = node.getCreatedTime|format_date('umami_dates') %}
-{{ attach_library('classy/node') }}
+{{ attach_library('umami/classy.node') }}
 
 <article{{ attributes.addClass(classes) }}>
 
diff --git a/core/tests/Drupal/KernelTests/Core/Theme/ThemesNotUsingClassyTemplatesTest.php b/core/tests/Drupal/KernelTests/Core/Theme/ThemesNotUsingClassyTemplatesTest.php
new file mode 100644
index 00000000000..e593bc577ef
--- /dev/null
+++ b/core/tests/Drupal/KernelTests/Core/Theme/ThemesNotUsingClassyTemplatesTest.php
@@ -0,0 +1,515 @@
+<?php
+
+namespace Drupal\KernelTests\Core\Theme;
+
+use Drupal\Core\Theme\Registry;
+use Drupal\KernelTests\KernelTestBase;
+
+/**
+ * Tests that themes do not depend on Classy templates.
+ *
+ * These tests exist to facilitate the process of decoupling themes from
+ * Classy. The decoupling process includes eliminating the use of Classy
+ * templates by providing theme-specific versions of templates that would
+ * otherwise be inherited from Classy.
+ *
+ * This test can be removed once the Classy decoupling is complete, and it will
+ * fail if it is still present when Classy is removed from Drupal core.
+ *
+ * @group Theme
+ */
+class ThemesNotUsingClassyTemplatesTest extends KernelTestBase {
+
+  /**
+   * {@inheritdoc}
+   */
+  public static $modules = ['system', 'user'];
+
+  /**
+   * The theme handler.
+   *
+   * @var \Drupal\Core\Extension\ThemeHandlerInterface
+   */
+  protected $themeHandler;
+
+  /**
+   * Templates that are identical in Stable, which means they can be skipped.
+   *
+   * In several cases, the templates in Classy are identical to those in
+   * Stable. This means that a theme would behave identically even if those
+   * templates were removed from Classy. They are effectively decoupled from
+   * Classy already as they rely on no functionality unique to Classy.
+   *
+   * @var string[]
+   *
+   * @see \Drupal\Tests\Core\Theme\ClassyTemplatesIdenticalToStableTest for a
+   *   test that confirms that these templates are identical.
+   */
+  protected $templatesSkippableBecauseIdenticalToStable = [
+    'file-upload-help',
+    'file-widget-multiple',
+    'image-formatter',
+    'image-style',
+    'checkboxes',
+    'confirm-form',
+    'container',
+    'dropbutton-wrapper',
+    'field-multiple-value-form',
+    'form',
+    'input',
+    'select',
+    'links',
+    'menu-local-action',
+    'pager',
+    'vertical-tabs',
+    'views-view-grid',
+    'views-view-list',
+    'views-view-mapping-test',
+    'views-view-opml',
+    'views-view-row-opml',
+    'views-view-rss',
+    'views-view-unformatted',
+  ];
+
+  /**
+   * {@inheritdoc}
+   */
+  protected function setUp() {
+    parent::setUp();
+    $this->themeHandler = $this->container->get('theme_handler');
+    $this->container->get('theme_installer')->install([
+      'umami',
+      'bartik',
+      'seven',
+      'claro',
+    ]);
+    // Enable all modules so every template is present in the theme registry.
+    // This makes it possible to check the source of every template and
+    // determine if they come from Classy.
+    $this->installAllModules();
+  }
+
+  /**
+   * Installs all core modules.
+   */
+  protected function installAllModules() {
+    // Enable all core modules.
+    $all_modules = $this->container->get('extension.list.module')->getList();
+    $all_modules = array_filter($all_modules, function ($module) {
+      // Filter contrib, hidden, experimental, already enabled modules, and
+      // modules in the Testing package.
+      if ($module->origin !== 'core' || !empty($module->info['hidden']) || $module->status === TRUE || $module->info['package'] === 'Testing' || $module->info['package'] === 'Core (Experimental)') {
+        return FALSE;
+      }
+      return TRUE;
+    });
+    $all_modules = array_keys($all_modules);
+    $module_installer = $this->container->get('module_installer');
+    $module_installer->install($all_modules);
+  }
+
+  /**
+   * Ensures that themes are not inheriting templates from Classy.
+   *
+   * @param string $theme
+   *   The theme to test.
+   * @param string[] $templates_to_skip
+   *   Templates that will not be tested.
+   *
+   * @dataProvider providerTestThemesTemplatesNotClassy
+   */
+  public function testThemesTemplatesNotClassy($theme, array $templates_to_skip) {
+    // Get every template available to the theme being tested.
+    $theme_registry = new Registry($this->root, \Drupal::cache(), \Drupal::lock(), \Drupal::moduleHandler(), $this->themeHandler, \Drupal::service('theme.initialization'), $theme);
+    $theme_registry->setThemeManager(\Drupal::theme());
+    $theme_registry_full = $theme_registry->get();
+
+    // Loop through every template available to the current theme, confirm it
+    // does not come from Classy, does not attach Classy libraries, and does not
+    // extend or include Classy templates.
+    foreach ($theme_registry_full as $info) {
+      if (isset($info['template'])) {
+        $template_name = $info['template'];
+
+        if (in_array($template_name, $templates_to_skip) || in_array($template_name, $this->templatesSkippableBecauseIdenticalToStable)) {
+          continue;
+        }
+
+        $template_contents = file_get_contents("{$this->root}/{$info['path']}/$template_name.html.twig");
+
+        // Confirm template does not come from Classy.
+        $this->assertFalse($info['theme path'] === 'core/themes/classy', "$theme is inheriting $template_name from Classy.");
+
+        // Confirm template does not include or extend Classy templates.
+        preg_match_all('/(extends|include)\s+(\'|")@classy/', $template_contents, $classy_extend_include_matches);
+        $this->assertEmpty($classy_extend_include_matches[0], "The template: '$template_name' in the theme: '$theme' includes or extends a Classy template.");
+
+        // Confirm template does not attach a Classy library.
+        preg_match_all('/attach_library\((\'|")classy\/.+(\'|")\)/', $template_contents, $classy_extend_library_matches);
+        $this->assertEmpty($classy_extend_library_matches[0], "The template: '$template_name' in the theme: '$theme' attaches a Classy library.");
+      }
+    }
+  }
+
+  /**
+   * Data provider for testThemesTemplatesNotClassy().
+   *
+   * @return array
+   *   Array of test cases using these keys:
+   *    -'theme-name': The machine name of the theme being tested.
+   *    -'to-skip': Templates that will skipped by the test.
+   */
+  public function providerTestThemesTemplatesNotClassy() {
+    // Each item provides the theme name and an array of templates to skip. The
+    // templates in the to-skip array are ones that have not yet been decoupled
+    // from Classy. When a template is properly decoupled from Classy, it can be
+    // removed from to-skip. If this test passes with an empty to-skip array,
+    // this is confirmation that the templates are fully decoupled form Classy.
+    return [
+      'umami' => [
+        'theme-name' => 'umami',
+        'to-skip' => [
+          'aggregator-feed',
+          'aggregator-item',
+          'block',
+          'book-export-html',
+          'book-all-books-block',
+          'book-tree',
+          'book-navigation',
+          'book-node-export-html',
+          'comment',
+          'field--comment',
+          'file-managed-file',
+          'file-audio',
+          'file-link',
+          'file-video',
+          'filter-guidelines',
+          'filter-tips',
+          'text-format-wrapper',
+          'filter-caption',
+          'form-element-label',
+          'forum-list',
+          'forum-icon',
+          'forums',
+          'forum-submitted',
+          'help-section',
+          'image-widget',
+          'link-formatter-link-separate',
+          'media-embed-error',
+          'media',
+          'media--media-library',
+          'media-library-wrapper',
+          'media-library-item',
+          'views-view-unformatted--media-library',
+          'item-list--search-results',
+          'links--node',
+          'field--text',
+          'field--text-long',
+          'field--text-with-summary',
+          'links--media-library-menu',
+          'container--media-library-content',
+          'media-library-item--small',
+          'container--media-library-widget-selection',
+          'block--local-tasks-block',
+          'block--search-form-block',
+          'node-edit-form',
+          'node-add-list',
+          'field--node--uid',
+          'field--node--title',
+          'field--node--created',
+          'rdf-metadata',
+          'search-result',
+          'progress-bar',
+          'datetime-wrapper',
+          'fieldset',
+          'datetime-form',
+          'textarea',
+          'details',
+          'form-element',
+          'radios',
+          'item-list',
+          'table',
+          'maintenance-page',
+          'html',
+          'region',
+          'breadcrumb',
+          'menu-local-tasks',
+          'page-title',
+          'mark',
+          'time',
+          'image',
+          'field',
+          'block--local-actions-block',
+          'block--system-menu-block',
+          'taxonomy-term',
+          'toolbar',
+          'username',
+          'user',
+          'views-form-views-form',
+          'views-mini-pager',
+          'views-exposed-form',
+          'views-view-grouping',
+          'views-view-summary',
+          'views-view-table',
+          'views-view-row-rss',
+          'views-view-summary-unformatted',
+          'views-view',
+        ],
+      ],
+      'seven' => [
+        'theme-name' => 'seven',
+        'to-skip' => [
+          'aggregator-feed',
+          'aggregator-item',
+          'block--system-branding-block',
+          'block',
+          'breadcrumb',
+          'book-export-html',
+          'book-all-books-block',
+          'book-tree',
+          'book-navigation',
+          'book-node-export-html',
+          'comment',
+          'field--comment',
+          'file-managed-file',
+          'file-audio',
+          'file-link',
+          'file-video',
+          'filter-guidelines',
+          'filter-tips',
+          'text-format-wrapper',
+          'filter-caption',
+          'form-element-label',
+          'forum-list',
+          'forum-icon',
+          'forums',
+          'forum-submitted',
+          'help-section',
+          'link-formatter-link-separate',
+          'media-embed-error',
+          'media',
+          'media--media-library',
+          'media-library-wrapper',
+          'media-library-item',
+          'views-view-unformatted--media-library',
+          'item-list--search-results',
+          'links--node',
+          'field--text',
+          'field--text-long',
+          'field--text-with-summary',
+          'links--media-library-menu',
+          'container--media-library-content',
+          'media-library-item--small',
+          'container--media-library-widget-selection',
+          'block--local-tasks-block',
+          'block--search-form-block',
+          'node',
+          'field--node--uid',
+          'field--node--title',
+          'field--node--created',
+          'rdf-metadata',
+          'search-result',
+          'progress-bar',
+          'status-messages',
+          'datetime-wrapper',
+          'fieldset',
+          'datetime-form',
+          'textarea',
+          'form-element',
+          'radios',
+          'item-list',
+          'table',
+          'html',
+          'region',
+          'menu',
+          'menu-local-task',
+          'page-title',
+          'mark',
+          'time',
+          'image',
+          'field',
+          'block--system-menu-block',
+          'taxonomy-term',
+          'toolbar',
+          'username',
+          'user',
+          'views-form-views-form',
+          'views-mini-pager',
+          'views-exposed-form',
+          'views-view-grouping',
+          'views-view-summary',
+          'views-view-table',
+          'views-view-row-rss',
+          'views-view-summary-unformatted',
+          'views-view',
+        ],
+      ],
+      'claro' => [
+        'theme-name' => 'claro',
+        'to-skip' => [
+          'aggregator-feed',
+          'aggregator-item',
+          'block--system-branding-block',
+          'block',
+          'book-export-html',
+          'book-all-books-block',
+          'book-tree',
+          'book-navigation',
+          'book-node-export-html',
+          'comment',
+          'field--comment',
+          'file-audio',
+          'file-video',
+          'filter-caption',
+          'forum-list',
+          'forum-icon',
+          'forums',
+          'forum-submitted',
+          'help-section',
+          'link-formatter-link-separate',
+          'media-embed-error',
+          'media',
+          'media--media-library',
+          'media-library-wrapper',
+          'media-library-item',
+          'views-view-unformatted--media-library',
+          'item-list--search-results',
+          'links--node',
+          'field--text',
+          'field--text-long',
+          'field--text-with-summary',
+          'links--media-library-menu',
+          'container--media-library-content',
+          'media-library-item--small',
+          'container--media-library-widget-selection',
+          'block--local-tasks-block',
+          'block--search-form-block',
+          'node',
+          'field--node--uid',
+          'field--node--title',
+          'field--node--created',
+          'rdf-metadata',
+          'search-result',
+          'progress-bar',
+          'textarea',
+          'radios',
+          'item-list',
+          'table',
+          'html',
+          'region',
+          'menu',
+          'page-title',
+          'mark',
+          'time',
+          'image',
+          'field',
+          'block--local-actions-block',
+          'block--system-menu-block',
+          'taxonomy-term',
+          'toolbar',
+          'username',
+          'user',
+          'views-form-views-form',
+          'views-view-grouping',
+          'views-view-summary',
+          'views-view-table',
+          'views-view-row-rss',
+          'views-view-summary-unformatted',
+          'views-view',
+        ],
+      ],
+      'bartik' => [
+        'theme-name' => 'bartik',
+        'to-skip' => [
+          'aggregator-feed',
+          'aggregator-item',
+          'block--system-branding-block',
+          'block',
+          'book-export-html',
+          'book-all-books-block',
+          'book-tree',
+          'book-navigation',
+          'book-node-export-html',
+          'comment',
+          'field--comment',
+          'file-managed-file',
+          'file-audio',
+          'file-link',
+          'file-video',
+          'filter-guidelines',
+          'filter-tips',
+          'text-format-wrapper',
+          'filter-caption',
+          'forum-list',
+          'forum-icon',
+          'forums',
+          'forum-submitted',
+          'help-section',
+          'image-widget',
+          'link-formatter-link-separate',
+          'media-embed-error',
+          'media',
+          'media--media-library',
+          'media-library-wrapper',
+          'media-library-item',
+          'views-view-unformatted--media-library',
+          'item-list--search-results',
+          'links--node',
+          'field--text',
+          'field--text-long',
+          'field--text-with-summary',
+          'links--media-library-menu',
+          'container--media-library-content',
+          'media-library-item--small',
+          'container--media-library-widget-selection',
+          'block--local-tasks-block',
+          'node-edit-form',
+          'node-add-list',
+          'field--node--uid',
+          'field--node--title',
+          'field--node--created',
+          'rdf-metadata',
+          'search-result',
+          'progress-bar',
+          'datetime-wrapper',
+          'fieldset',
+          'datetime-form',
+          'textarea',
+          'details',
+          'form-element',
+          'form-element-label',
+          'radios',
+          'item-list',
+          'table',
+          'page',
+          'maintenance-page',
+          'html',
+          'region',
+          'menu',
+          'menu-local-task',
+          'breadcrumb',
+          'menu-local-tasks',
+          'mark',
+          'time',
+          'image',
+          'field',
+          'block--local-actions-block',
+          'taxonomy-term',
+          'toolbar',
+          'username',
+          'user',
+          'views-mini-pager',
+          'views-exposed-form',
+          'views-form-views-form',
+          'views-view-grouping',
+          'views-view-summary',
+          'views-view-table',
+          'views-view-row-rss',
+          'views-view-summary-unformatted',
+          'views-view',
+        ],
+      ],
+    ];
+  }
+
+}
diff --git a/core/themes/bartik/templates/block--search-form-block.html.twig b/core/themes/bartik/templates/block--search-form-block.html.twig
index b2af1edf2b4..1f9adf0d326 100644
--- a/core/themes/bartik/templates/block--search-form-block.html.twig
+++ b/core/themes/bartik/templates/block--search-form-block.html.twig
@@ -1,23 +1,48 @@
-{% extends "@classy/block/block--search-form-block.html.twig" %}
 {#
 /**
  * @file
- * Bartik's theme implementation for a search form block. Extends Classy's
- * search form block template.
+ * Bartik's theme implementation for a search form block.
  *
  * Available variables:
+ * - plugin_id: The ID of the block implementation.
+ * - label: The configured label of the block if visible.
+ * - configuration: A list of the block's configuration values, including:
+ *   - label: The configured label for the block.
+ *   - label_display: The display settings for the label.
+ *   - provider: The module or other provider that provided this block plugin.
+ *   - Block plugin specific settings will also be stored here.
  * - content: The content of this block.
  * - content_attributes: A list of HTML attributes applied to the main content
+ * - attributes: A list HTML attributes populated by modules, intended to
+ *   be added to the main container tag of this template. Includes:
+ *   - id: A valid HTML ID and guaranteed unique.
+ * - title_attributes: Same as attributes, except applied to the main title
  *   tag that appears in the template.
+ * - title_prefix: Additional output populated by modules, intended to be
+ *   displayed in front of the main title tag that appears in the template.
+ * - title_suffix: Additional output populated by modules, intended to be
+ *   displayed after the main title tag that appears in the template.
  *
  * @see template_preprocess_block()
  * @see search_preprocess_block()
- *
- * @ingroup themeable
  */
 #}
-{% block content %}
-  <div{{ content_attributes.addClass('content', 'container-inline') }}>
-    {{ parent() }}
-  </div>
-{% endblock %}
+{%
+  set classes = [
+    'block',
+    'block-search',
+    'container-inline',
+  ]
+%}
+<div{{ attributes.addClass(classes) }}>
+  {{ title_prefix }}
+  {% if label %}
+    <h2{{ title_attributes }}>{{ label }}</h2>
+  {% endif %}
+  {{ title_suffix }}
+  {% block content %}
+    <div{{ content_attributes.addClass('content', 'container-inline') }}>
+      {{ content }}
+    </div>
+  {% endblock %}
+</div>
diff --git a/core/themes/bartik/templates/block--system-menu-block.html.twig b/core/themes/bartik/templates/block--system-menu-block.html.twig
index d22cfbf9316..aea280820ef 100644
--- a/core/themes/bartik/templates/block--system-menu-block.html.twig
+++ b/core/themes/bartik/templates/block--system-menu-block.html.twig
@@ -1,21 +1,66 @@
-{% extends "@classy/block/block--system-menu-block.html.twig" %}
 {#
 /**
  * @file
  * Bartik's theme implementation for a menu block.
  *
- * @ingroup themeable
+ * Available variables:
+ * - plugin_id: The ID of the block implementation.
+ * - label: The configured label of the block if visible.
+ * - configuration: A list of the block's configuration values.
+ *   - label: The configured label for the block.
+ *   - label_display: The display settings for the label.
+ *   - provider: The module or other provider that provided this block plugin.
+ *   - Block plugin specific settings will also be stored here.
+ * - content: The content of this block.
+ * - attributes: HTML attributes for the containing element.
+ *   - id: A valid HTML ID and guaranteed unique.
+ * - title_attributes: HTML attributes for the title element.
+ * - content_attributes: HTML attributes for the content element.
+ * - title_prefix: Additional output populated by modules, intended to be
+ *   displayed in front of the main title tag that appears in the template.
+ * - title_suffix: Additional output populated by modules, intended to be
+ *   displayed after the main title tag that appears in the template.
+ *
+ * Headings should be used on navigation menus that consistently appear on
+ * multiple pages. When this menu block's label is configured to not be
+ * displayed, it is automatically made invisible using the 'visually-hidden' CSS
+ * class, which still keeps it visible for screen-readers and assistive
+ * technology. Headings allow screen-reader and keyboard only users to navigate
+ * to or skip the links.
+ * See http://juicystudio.com/article/screen-readers-display-none.php and
+ * http://www.w3.org/TR/WCAG-TECHS/H42.html for more information.
  */
 #}
+{%
+  set classes = [
+    'block',
+    'block-menu',
+    'navigation',
+    'menu--' ~ derivative_plugin_id|clean_class,
+  ]
+%}
+{% set heading_id = attributes.id ~ '-menu'|clean_id %}
 {% set show_anchor = "show-" ~ attributes.id|clean_id %}
 {% set hide_anchor = "hide-" ~ attributes.id|clean_id %}
-{% block content %}
-  <div{{ content_attributes.addClass('content') }}>
-    {# When rendering a menu without label, render a menu toggle. #}
-    <div class="menu-toggle-target menu-toggle-target-show" id="{{ show_anchor }}"></div>
-    <div class="menu-toggle-target" id="{{ hide_anchor }}"></div>
-    <a class="menu-toggle" href="#{{ show_anchor }}">{% trans %} Show &mdash; {{ configuration.label }}{% endtrans %}</a>
-    <a class="menu-toggle menu-toggle--hide" href="#{{ hide_anchor }}">{% trans %} Hide &mdash; {{ configuration.label }}{% endtrans %}</a>
-    {{ content }}
-  </div>
-{% endblock %}
+
+<nav role="navigation" aria-labelledby="{{ heading_id }}"{{ attributes.addClass(classes)|without('role', 'aria-labelledby') }}>
+  {# Label. If not displayed, we still provide it for screen readers. #}
+  {% if not configuration.label_display %}
+    {% set title_attributes = title_attributes.addClass('visually-hidden') %}
+  {% endif %}
+  {{ title_prefix }}
+  <h2{{ title_attributes.setAttribute('id', heading_id) }}>{{ configuration.label }}</h2>
+  {{ title_suffix }}
+
+  {# Menu. #}
+  {% block content %}
+    <div{{ content_attributes.addClass('content') }}>
+      {# When rendering a menu without label, render a menu toggle. #}
+      <div class="menu-toggle-target menu-toggle-target-show" id="{{ show_anchor }}"></div>
+      <div class="menu-toggle-target" id="{{ hide_anchor }}"></div>
+      <a class="menu-toggle" href="#{{ show_anchor }}">{% trans %} Show &mdash; {{ configuration.label }}{% endtrans %}</a>
+      <a class="menu-toggle menu-toggle--hide" href="#{{ hide_anchor }}">{% trans %} Hide &mdash; {{ configuration.label }}{% endtrans %}</a>
+      {{ content }}
+    </div>
+  {% endblock %}
+</nav>
diff --git a/core/themes/bartik/templates/node.html.twig b/core/themes/bartik/templates/node.html.twig
index c7495223fed..c0df4837abb 100644
--- a/core/themes/bartik/templates/node.html.twig
+++ b/core/themes/bartik/templates/node.html.twig
@@ -77,7 +77,7 @@
     'clearfix',
   ]
 %}
-{{ attach_library('classy/node') }}
+{{ attach_library('claro/classy.node') }}
 <article{{ attributes.addClass(classes) }}>
   <header>
     {{ title_prefix }}
diff --git a/core/themes/bartik/templates/page-title.html.twig b/core/themes/bartik/templates/page-title.html.twig
index e061cd2e019..4d12311f87f 100644
--- a/core/themes/bartik/templates/page-title.html.twig
+++ b/core/themes/bartik/templates/page-title.html.twig
@@ -1,4 +1,3 @@
-{% extends "@classy/content/page-title.html.twig" %}
 {#
 /**
  * @file
@@ -13,4 +12,15 @@
  *   displayed after the main title tag that appears in the template.
  */
 #}
-{% set title_attributes = title_attributes.addClass('title') %}
+{%
+  set classes = [
+    'title',
+    'page-title',
+  ]
+%}
+
+{{ title_prefix }}
+{% if title %}
+  <h1{{ title_attributes.addClass(classes) }}>{{ title }}</h1>
+{% endif %}
+{{ title_suffix }}
diff --git a/core/themes/bartik/templates/status-messages.html.twig b/core/themes/bartik/templates/status-messages.html.twig
index e822ff5fbb9..700593206e0 100644
--- a/core/themes/bartik/templates/status-messages.html.twig
+++ b/core/themes/bartik/templates/status-messages.html.twig
@@ -1,4 +1,3 @@
-{% extends "@classy/misc/status-messages.html.twig" %}
 {#
 /**
  * @file
@@ -16,13 +15,46 @@
  * Available variables:
  * - message_list: List of messages to be displayed, grouped by type.
  * - status_headings: List of all status types.
+ * - attributes: HTML attributes for the element, including:
+ *   - class: HTML classes.
  */
 #}
-{% block messages %}
-  {% if message_list is not empty %}
-    {{ attach_library('bartik/messages') }}
-    <div class="messages__wrapper layout-container">
-      {{ parent() }}
-    </div>
-  {% endif %}
-{% endblock messages %}
+<div data-drupal-messages>
+  {% block messages %}
+    {% if message_list is not empty %}
+      {{ attach_library('bartik/messages') }}
+      <div class="messages__wrapper layout-container">
+        {% for type, messages in message_list %}
+          {%
+            set classes = [
+            'messages',
+            'messages--' ~ type,
+          ]
+          %}
+          <div role="contentinfo" aria-label="{{ status_headings[type] }}"{{ attributes.addClass(classes)|without('role', 'aria-label') }}>
+            {% if type == 'error' %}
+            <div role="alert">
+              {% endif %}
+              {% if status_headings[type] %}
+                <h2 class="visually-hidden">{{ status_headings[type] }}</h2>
+              {% endif %}
+              {% if messages|length > 1 %}
+                <ul class="messages__list">
+                  {% for message in messages %}
+                    <li class="messages__item">{{ message }}</li>
+                  {% endfor %}
+                </ul>
+              {% else %}
+                {{ messages|first }}
+              {% endif %}
+              {% if type == 'error' %}
+            </div>
+            {% endif %}
+          </div>
+          {# Remove type specific classes. #}
+          {% set attributes = attributes.removeClass(classes) %}
+        {% endfor %}
+      </div>
+    {% endif %}
+  {% endblock messages %}
+</div>
diff --git a/core/themes/claro/templates/field/file-link.html.twig b/core/themes/claro/templates/field/file-link.html.twig
index 891c7a124d3..07cd9e8561d 100644
--- a/core/themes/claro/templates/field/file-link.html.twig
+++ b/core/themes/claro/templates/field/file-link.html.twig
@@ -14,5 +14,5 @@
  * @see stable_preprocess_image_widget()
  */
 #}
-{{ attach_library('classy/file') }}
+{{ attach_library('claro/classy.file') }}
 <span{{ attributes }}>{{ link }} <span class="file__size">({{ file_size }})</span></span>
diff --git a/core/themes/claro/templates/form-element-label.html.twig b/core/themes/claro/templates/form-element-label.html.twig
index f05010d686d..d0ec8a3b1a0 100644
--- a/core/themes/claro/templates/form-element-label.html.twig
+++ b/core/themes/claro/templates/form-element-label.html.twig
@@ -2,11 +2,25 @@
 /**
  * @file
  * Template override for a form element label.
+ *
+ * Available variables:
+ * - title: The label's text.
+ * - title_display: Elements title_display setting.
+ * - required: An indicator for whether the associated form element is required.
+ * - attributes: A list of HTML attributes for the label.
+ *
+ * @see template_preprocess_form_element_label()
  */
 #}
-
-{% extends '@classy/form/form-element-label.html.twig' %}
-
 {%
-  set attributes = attributes.addClass('form-item__label')
+  set classes = [
+    'form-item__label',
+    title_display == 'after' ? 'option',
+    title_display == 'invisible' ? 'visually-hidden',
+    required ? 'js-form-required',
+    required ? 'form-required',
+  ]
 %}
+{% if title is not empty or required -%}
+  <label{{ attributes.addClass(classes) }}>{{ title }}</label>
+{%- endif %}
diff --git a/core/themes/seven/templates/image-widget.html.twig b/core/themes/seven/templates/image-widget.html.twig
index a7cf3ad48a1..2d6f4014ed5 100644
--- a/core/themes/seven/templates/image-widget.html.twig
+++ b/core/themes/seven/templates/image-widget.html.twig
@@ -3,10 +3,23 @@
  * @file
  * Theme override for an image field widget.
  *
- * Included from Classy theme.
+ * Available variables:
+ * - attributes: HTML attributes for the containing element.
+ * - data: Render elements of the image widget.
  *
  * @see template_preprocess_image_widget()
  */
 #}
-{% include '@classy/content-edit/image-widget.html.twig' %}
-{{ attach_library('classy/image-widget') }}
+{{ attach_library('seven/classy.image-widget') }}
+
+<div{{ attributes }}>
+  {% if data.preview %}
+    <div class="image-preview">
+      {{ data.preview }}
+    </div>
+  {% endif %}
+  <div class="image-widget-data">
+    {# Render widget data without the image preview that was output already. #}
+    {{ data|without('preview') }}
+  </div>
+</div>