Add a check for upgrader_process_complete

[terriann]

What problem would the enhancement address for VIP?

Because the contents of /wp-content/plugins and /wp-content/themes are setup as read-only directories, and end-users can't install or update plugins from within the wp-admin, the hook upgrader_process_complete will never run for either plugin install or update on the VIP Go platform.

When a VIP customer installs a plugin (via the GitHub repo) with a function tied to that hook, their development team has to reverse engineer the plugin's code to execute that functionality.

This is not entirely unique to VIP, but only impacts WordPress environments where the /wp-content/plugins and /wp-content/themes are read-only, so it may not be a good fit for the WordPress Coding Standards.

Describe the solution you'd like

A sniff that will flag places where the upgrader_process_complete hook is used. Preferably as an error because it is functionality that will not work.

What code should be reported as a violation?

add_action( 'upgrader_process_complete', 'my_upgrade_function',10, 2);

What code should not be reported as a violation?

I'm unaware of cases where this might be detected as a false positive.

Additional context

None applicable