Health check should list all feature flags in core and show which features the current theme supports

[pbearne]

It would be nice to be a see what features your theme supports and to have links to core docs To explain what each feature flag does.

I see this as list of all features globally available (core and others) with ticks for each feature the current theme supports

[vimes1984]

This would be great, other teams could then produce user and dev-facing documentation with regards to the feature encouraging overall searchability of the feature and encouraging adoption by end-users.

[pbearne]

link to the ​https://developer.wordpress.org/reference/functions/add_theme_support/

[oglekler]

I have no idea what is the right way to know in time about new support features and sometimes it is difficult to understand if something isn't working during development and it caused by the absence of this support declaration. Most times I am looking in WordPress default themes and other popular themes for this piece of information and something learning new 'tricks' or possibilities I happened to miss along the way but I doubt that it is the right way to get the information.

The tricky bit is that plugins can use their own theme support declarations and it is difficult to find if you don't know what you are looking for. For example, if a theme isn't supporting 'woocommerce', WC will not be using templates from the theme's folder but the plugin has its own bits for compatibility with default themes and as result, if you will make a child theme for the default one, it will be using templates from child's folder. It is a bit confusing if you don't know that plugin can declare the support for the theme instead of the theme itself.

[Clorith]

The current Site Health implementation will, in the debug information tab, show the active theme and which features it has self-declared (based on the tags field in the style.css file).

Although not always a 1-to-1 relationship with the add_theme_support() entry, this does feel like the more correct way to surface this kind of information, since they are tags the user can filter on in the themes screens, and gives a better understanding of what the theme does. Looking at it from another perspective, what would it tell the end user that html5, admin-bar, or editor-color-palette is defined in code?