Include specific checks for plugins that declare Multisite compatibility

The Problem

As a WordPress Multisite administrator, I frequently encounter plugins that claim Multisite compatibility, but fail to work correctly or introduce issues when activated on a Multisite network.

I understand the Plugin Check Plugin (PCP), at this stage, does not have any specific checks to validate a plugin's claim of Multisite compatibility.

The main issues are:

• Wasting time installing, testing, and debugging plugins that are advertised as compatible but are clearly not.
• Users becoming wary of these claims, even when a plugin might genuinely be compatible.
• Developers not realizing their plugin has Multisite issues until users report them.

Possible Solution

I suggest enhancing the Plugin Check Plugin (PCP), gradually over time, to include specific checks for plugins that declare Multisite compatibility.

I understand that comprehensive functional testing of all Multisite scenarios is incredibly complex. However, integrating some static analysis checks for common Multisite development patterns and potential pitfalls within PCP would be a significant step forward. This would help flag common issues improving the overall quality of plugins available to the large Multisite community.

Currently, the alternative is manual testing by Multisite users, which is time-consuming, prone to error, and reactive rather than proactive.

Developers also tend to rely on user bug reports to highlight problems, which is cumbersome & often ineffective. Adding Multisite compatibility to PCP should help encourage developers to test their plugins appropriately for WordPress Multisite.

Thank you for considering this enhancement.

The issue does not name files, tests, or an entry point. Start by reviewing the Plugin Check Plugin's existing static checks and how plugins declare Multisite compatibility, then identify a narrowly scoped common pattern to validate. Done should include an agreed check, coverage for its expected behavior, and documentation of the finding.