RSS output not valid when using Twig debug

I also continue seeing.

Before patch:

<!-- THEME DEBUG -->
<!-- THEME HOOK: 'views_view_rss' -->
<!-- BEGIN OUTPUT from 'core/modules/views/templates/views-view-rss.html.twig' -->
<?xml version="1.0" encoding="utf-8"?>
<rss version="2.0" xml:base="http://drupal10.lndo.site/" xmlns:dc="http://purl.org/dc/elements/1.1/">
  <channel>
    <title>Blog Posts</title>
    <link>http://drupal10.lndo.site/</link>
    <description></description>
    <language>en</language>
    
    

<!-- THEME DEBUG -->
<!-- THEME HOOK: 'views_view_row_rss' -->
<!-- BEGIN OUTPUT from 'core/modules/views/templates/views-view-row-rss.html.twig' -->
<item>
  <title>Second Blog</title>
  <link>http://drupal10.lndo.site/blog-2</link>
  <description>

&lt;!-- THEME DEBUG --&gt;
&lt;!-- THEME HOOK: &#039;field&#039; --&gt;
&lt;!-- FILE NAME SUGGESTIONS:
   * field--node--title--blog.html.twig
   x field--node--title.html.twig
   * field--node--blog.html.twig
   * field--title.html.twig
   * field--string.html.twig
   * field.html.twig
--&gt;
&lt;!-- BEGIN OUTPUT from &#039;core/modules/node/templates/field--node--title.html.twig&#039; --&gt;

&lt;span&gt;Second Blog&lt;/span&gt;

&lt;!-- END OUTPUT from &#039;core/modules/node/templates/field--node--title.html.twig&#039; --&gt;

After patch:

<?xml version="1.0" encoding="utf-8"?>
<rss xmlns:dc="http://purl.org/dc/elements/1.1/" version="2.0" xml:base="http://drupal10.lndo.site/">
  <channel>
    <title>Blog Posts</title>
    <link>http://drupal10.lndo.site/</link>
    <description/>
    <language>en</language>
    
    <item>
  <title>Second Blog</title>
  <link>http://drupal10.lndo.site/blog-2</link>
  <description>

&lt;!-- THEME DEBUG --&gt;
&lt;!-- THEME HOOK: 'field' --&gt;
&lt;!-- FILE NAME SUGGESTIONS:
   * field--node--title--blog.html.twig
   x field--node--title.html.twig
   * field--node--blog.html.twig
   * field--title.html.twig
   * field--string.html.twig
   * field.html.twig
--&gt;
&lt;!-- BEGIN OUTPUT from 'core/modules/node/templates/field--node--title.html.twig' --&gt;

&lt;span&gt;Second Blog&lt;/span&gt;

&lt;!-- END OUTPUT from 'core/modules/node/templates/field--node--title.html.twig' --&gt;



&lt;!-- THEME DEBUG --&gt;
&lt;!-- THEME HOOK: 'field' --&gt;
&lt;!-- FILE NAME SUGGESTIONS:
   * field--node--uid--blog.html.twig
   x field--node--uid.html.twig
   * field--node--blog.html.twig
   * field--uid.html.twig
   * field--entity-reference.html.twig
   * field.html.twig
--&gt;
&lt;!-- BEGIN OUTPUT from 'core/modules/node/templates/field--node--uid.html.twig' --&gt;

&lt;span&gt;

Creating merge request.

VladimirAus → changed the visibility of the branch 2796453-rss-output-not to hidden.

So it’s ready to review?!

Feel free to update if not yet

Issue summary still appears to need to updating.

Can the MR be updated to 11.x vs 11.0.x please

Fixes are made on on 11.x (our main development branch) first, and are then back ported as needed according to our policies.

VladimirAus → changed the visibility of the branch 2796453-rss-output-not to active.

VladimirAus → changed the visibility of the branch 2796453-twig-rss-output-d11 to hidden.

Switched to 11.x branch.

Observed test failures, found there are some PHP coding standard related test failures , fixed those.

pipeline passed successfully & MR is mergeable now.

$debug_blacklisted = isset($variables['view']) && ($variables['view']->getDisplay()->getType() == 'feed');

This will output TRUE or FALSE (which was the objective)

What are your thoughts?

Makes sense.

Pipelines are passing now ~~ keeping this in review for further suggestions.

Seems like a fix that will need test coverage.

Here rolling patch #43 for Drupal 10.3.1.

@smustgrave, Need guidance there for test coverage, As we know issue replicate when theme debug enable, generally when we add test theme debug not visible for those generated test file.

Any suggestion for how can I enable the theme debug for test files so that to replicate issue for test coverage.