Update wp.sanitize.stripTags() to return empty string when not passed a string

[westonruter]

See #10833 (comment):

I’m late to the game, but do we expect any other type errors? I suppose we expect people to send things that are strings nominally, but may be missing.

However, if we make a positive assertion we wouldn’t have to chase this later.

if ( 'string' !== typeof $text ) {
	return '';
}

It turns out that passing a non-string in 6.9 would cause an error due to the replace() method not being available on it (probably). So the previous change in r61578 which added support for sanitizing numbers actually would have previously caused an error. So we can indeed just short-circuit when a non-string is passed.

Trac ticket: https://core.trac.wordpress.org/ticket/64574

Follow-up to:

• Fix regression in wp.sanitize.stripTags() when input is null or undefined #10833
• Refine wp.sanitize.stripTags() when input is an empty value #10856

Use of AI Tools

None

---

This Pull Request is for code review only. Please keep all other discussion in the Trac ticket. Do not merge this Pull Request. See GitHub Pull Requests for Code Review in the Core Handbook for more details.

[github-actions]

The following accounts have interacted with this PR and/or linked issues. I will continue to update these lists as activity occurs. You can also manually ask me to refresh this list by adding the props-bot label.

Core Committers: Use this line as a base for the props when committing in SVN:

Props westonruter.

To understand the WordPress project's expectations around crediting contributors, please review the Contributor Attribution page in the Core Handbook.

[westonruter]

@Hug0-Drelon How does this work for you?

[github-actions]

Test using WordPress Playground

The changes in this pull request can previewed and tested using a WordPress Playground instance.

WordPress Playground is an experimental project that creates a full WordPress instance entirely within the browser.

Some things to be aware of

• All changes will be lost when closing a tab with a Playground instance.
• All changes will be lost when refreshing the page.
• A fresh instance is created each time the link below is clicked.
• Every time this pull request is updated, a new ZIP file containing all changes is created. If changes are not reflected in the Playground instance,
  it's possible that the most recent build failed, or has not completed. Check the list of workflow runs to be sure.

For more details about these limitations and more, check out the Limitations page in the WordPress Playground documentation.

Test this pull request with WordPress Playground.