Issue #2885098 by philipnorton42, gapple, ksbuble, MerryHamster, Suresh Prabhu...

    $build = \Drupal::entityTypeManager()

      ->getViewBuilder('node')

      ->view($node, $build_mode);

    // Add rss key to cache to differentiate this from other caches.

    $build['#cache']['keys'][] = 'view_rss';

    unset($build['#theme']);

    if (!empty($node->rss_namespaces)) {

langcode: en

status: true

dependencies:

  config:

    - core.entity_view_mode.node.teaser

    - node.type.article

  module:

    - node

    - user

id: test_node_article_feed

label: 'Test Node Article Feed'

module: views

description: ''

tag: ''

base_table: node_field_data

base_field: nid

display:

  default:

    display_plugin: default

    id: default

    display_title: Master

    position: 0

    display_options:

      access:

        type: perm

        options:

          perm: 'access content'

      cache:

        type: tag

        options: {  }

      query:

        type: views_query

        options:

          disable_sql_rewrite: false

          distinct: false

          replica: false

          query_comment: ''

          query_tags: {  }

      exposed_form:

        type: basic

        options:

          submit_button: Apply

          reset_button: false

          reset_button_label: Reset

          exposed_sorts_label: 'Sort by'

          expose_sort_order: true

          sort_asc_label: Asc

          sort_desc_label: Desc

      pager:

        type: mini

        options:

          items_per_page: 10

          offset: 0

          id: 0

          total_pages: null

          expose:

            items_per_page: false

            items_per_page_label: 'Items per page'

            items_per_page_options: '5, 10, 25, 50'

            items_per_page_options_all: false

            items_per_page_options_all_label: '- All -'

            offset: false

            offset_label: Offset

          tags:

            previous: ‹‹

            next: ››

      style:

        type: default

        options:

          grouping: {  }

          row_class: ''

          default_row_class: true

          uses_fields: false

      row:

        type: fields

        options:

          inline: {  }

          separator: ''

          hide_empty: false

          default_field_elements: true

      fields:

        title:

          id: title

          table: node_field_data

          field: title

          entity_type: node

          entity_field: title

          label: ''

          alter:

            alter_text: false

            make_link: false

            absolute: false

            trim: false

            word_boundary: false

            ellipsis: false

            strip_tags: false

            html: false

          hide_empty: false

          empty_zero: false

          settings:

            link_to_entity: true

          plugin_id: field

          relationship: none

          group_type: group

          admin_label: ''

          exclude: false

          element_type: ''

          element_class: ''

          element_label_type: ''

          element_label_class: ''

          element_label_colon: true

          element_wrapper_type: ''

          element_wrapper_class: ''

          element_default_classes: true

          empty: ''

          hide_alter_empty: true

          click_sort_column: value

          type: string

          group_column: value

          group_columns: {  }

          group_rows: true

          delta_limit: 0

          delta_offset: 0

          delta_reversed: false

          delta_first_last: false

          multi_type: separator

          separator: ', '

          field_api_classes: false

      filters:

        status:

          value: '1'

          table: node_field_data

          field: status

          plugin_id: boolean

          entity_type: node

          entity_field: status

          id: status

          expose:

            operator: ''

            operator_limit_selection: false

            operator_list: {  }

          group: 1

        type:

          id: type

          table: node_field_data

          field: type

          value:

            article: article

          entity_type: node

          entity_field: type

          plugin_id: bundle

          expose:

            operator_limit_selection: false

            operator_list: {  }

      sorts:

        created:

          id: created

          table: node_field_data

          field: created

          order: DESC

          entity_type: node

          entity_field: created

          plugin_id: date

          relationship: none

          group_type: group

          admin_label: ''

          exposed: false

          expose:

            label: ''

          granularity: second

      header: {  }

      footer: {  }

      empty: {  }

      relationships: {  }

      arguments: {  }

      display_extenders: {  }

    cache_metadata:

      max-age: -1

      contexts:

        - 'languages:language_content'

        - 'languages:language_interface'

        - url.query_args

        - 'user.node_grants:view'

        - user.permissions

      tags: {  }

  feed_1:

    display_plugin: feed

    id: feed_1

    display_title: 'Test Feed'

    position: 1

    display_options:

      display_extenders: {  }

      row:

        type: node_rss

        options:

          relationship: none

          view_mode: teaser

      path: test-node-article-feed

      display_description: ''

    cache_metadata:

      max-age: -1

      contexts:

        - 'languages:language_content'

        - 'languages:language_interface'

        - 'user.node_grants:view'

        - user.permissions

      tags: {  }

<?php

namespace Drupal\Tests\node\Functional;

use Drupal\filter\Entity\FilterFormat;

use Drupal\views\Tests\ViewTestData;

/**

 * Ensures that RSS render cache doesn't interfere with other caches.

 *

 * Create a node, render that node as a teaser in the RSS feed, ensure that

 * the RSS teaser render doesn't contain tags from the default theme.

 *

 * @group node

 */

class NodeRssCacheTest extends NodeTestBase {

  /**

   * {@inheritdoc}

   */

  protected static $modules = ['node_test', 'views', 'node_test_views'];

  /**

   * {@inheritdoc}

   */

  public static $testViews = ['test_node_article_feed'];

  /**

   * {@inheritdoc}

   */

  protected $defaultTheme = 'stark';

  /**

   * {@inheritdoc}

   */

  protected function setUp(): void {

    parent::setUp();

    ViewTestData::createTestViews(static::class, ['node_test_views']);

    // Use bypass node access permission here, because the test class uses

    // hook_grants_alter() to deny access to everyone on node_access

    // queries.

    $user = $this->drupalCreateUser([

      'bypass node access',

      'access content',

      'create article content',

    ]);

    $this->drupalLogin($user);

  }

  /**

   * Ensure the RSS teaser render does not interfere with default theme cache.

   */

  public function testNodeRssCacheContent() {

    // Only the plain_text text format is available by default, which escapes

    // all HTML.

    FilterFormat::create([

      'format' => 'full_html',

      'name' => 'Full HTML',

      'filters' => [],

    ])->save();

    // Create the test node.

    $node = $this->drupalCreateNode([

      'type' => 'article',

      'promote' => 1,

      'title' => 'Article Test Title',

      'body' => [

        'value' => '<p>Article test text.</p>',

        'format' => 'full_html',

      ],

    ]);

    // Render the node in the RSS feed view as a teaser.

    $this->drupalGet('test-node-article-feed');

    // Render the teaser normally.

    $viewBuilder = $this->container->get('entity_type.manager')->getViewBuilder('node');

    $build = $viewBuilder->view($node, 'teaser');

    $output = $this->container->get('renderer')->renderPlain($build);

    // Teaser must contain an "<article" tag from the stable9 theme.

    $this->assertStringContainsString('<article', (string) $output);

  }

}