Remove object-cache.php hack

[swissspidy]

Found out in #518 that this object-cache.php drop-in prevents other plugins from adding custom checks that can then be run via CLI.

From what I can see,object-cache.php is used as a "hook" to short-circuit regular WordPress loading order and manually execute the PCP CLI command before WordPress has fully loaded. That also means before any plugins have actually loaded...

This "hack" appears to be used so we can perform runtime checks for a plugin without the plugin having to be active on the site. If we can simply make this a requirement for the plugin to be active, then we can simplify this a lot.

I do lack full context though on why this was implemented this way, so appreciate any feedback.

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Related:

• Rethink the WP-CLI approach #153

[swissspidy]

@joemcgill @mukeshpanchal27 Do you perhaps more context on this whole early initialization thing with this object-cache.php drop-in? We could save ourselves some headaches by removing that...

[mukeshpanchal27]

@swissspidy I found #42, where it was introduced and discussed why it was added. Hope this helps to get more context.

[JJJ]

Due to the nature of how Plugin Check needs to work, only other way to load super early would be to require a stub from inside of wp-config.php, and do all the same work on either the mu_plugins_loaded or shutdown hooks, and that seems overly fragile & yucky considering Plugin Check is a core utility.

WordPress Core should just add support for a new drop-in: wp-content/plugin-check.php.

Plugin Check is the type of library that drop-in plugins are designed to accommodate; intentionally forked loading paths. Every existing drop-in overrides a low-level API or traps a related low-level problem, and it is an easy argument to make that Plugin Check has similarly low-level requirements.

Naming it something like I suggested above would also set the expectation to everyone that its usage is reserved, and if that file already exists it had better be compatible with Plugin Check, the same way all db.php drop-ins must extend wpdb.

[swissspidy]

I like the wp-content/plugin-check.php suggestion, but... do we really need to load super early? 🤔 That's what I am trying to understand better.

[ernilambar]

This issue came here also. #543 😟

[swissspidy]

Closing for now, can be revisited later