What?

Follows:

• Experiments: Rebuild the wp-admin Experiments screen on the wp-build routes pattern #77443

Ensure that Gutenberg experiments are actually active and truthy before outputting their JS global flags.

Why?

In #77443 where the experiments page was redesigned, switching an experiment to be off now means that the flag is set to false explicitly. Many of the experiments only checked to see if the array key exists, and so if the key existed but was set to false the experiment would unexpectedly be active 😱

This change updates all the experiments that were doing that to use the gutenberg_is_experiment_enabled utility function that performs a ! empty() check which means explicit false values will be treated as the experiment not being enabled.

How?

• Update the enable experiments code to use the gutenberg_is_experiment_enabled check instead of an array key exists check

Testing Instructions

• In trunk try toggling the Media Upload Modal on and off and notice that after activating it's impossible to switch off
• With this PR applied, toggling should work as expected
• Double-check each of the experiments updated here to make sure they're all toggling as expected

Screenshots or screencast

To show what I mean, toggle this experiment on and off at http://localhost:8888/wp-admin/admin.php?page=experiments-wp-admin:

Then go to the post editor and go to add a featured image, and you should see the core media modal:

And not this one, which should only show if the experiment is on:

Use of AI Tools

Claude Code