2.18.0 conflicting with certain themes, plugins

[JoshuaGoode]

Describe the bug:

While it doesn’t appear widespread, CoBlocks 2.18.0 is conflicting with some themes.

The site might experience style and element issues as well as issues handling XML-RPC requests.

This can prevent some front-end elements of plugins from working as expected as well.

It appears that when the conflict occurs, the following gets exposed across the site and is visible in places such as WP-CLI when running commands, XMLRPC and more.

<script type="text/javascript">
document.body.className = document.body.className.replace('no-js','js');
</script>

I don't have much more than that or a clean way of reproducing and seeing the issues it causes.

Here are some known themes so far.

• Consultera - https://wordpress.org/themes/consultera/
• Resonar - https://wordpress.org/themes/resonar/
• Creative Portfolio (Premium)
• Luxury (Premium) - https://organicthemes.com/theme/luxury-theme/
• Uptech (Premium)

To reproduce:

1. Install CoBlocks 2.18.0
2. Install a specific theme such as Resonar
3. With Resonar, the mobile menu with Child elements will always remain expanded.
4. Run some commands in WP-CLI, code can sometimes leak into output

Expected behavior:

Screenshots:

Isolating the problem:

• This bug happens with no other plugins activated
• This bug happens with a default WordPress theme active
• This bug happens without the Gutenberg plugin active
• I can reproduce this bug consistently using the steps above

WordPress version:

Gutenberg version:

[JoshuaGoode]

Most reports I've worked with are on WordPress.com but I can confirm the issue occurs on any host and in my local environments.

Looks like there's a report on the CoBlocks forums at https://wordpress.org/support/topic/site-logo-and-header-menu-not-showing-in-desktop-mobile/ as well.

[JoshuaGoode]

Related: 3f62717