I appreciate the script that you have in place for testing compatibility before upgrading. That's a useful idea. But the current script lists all of the php files in a site, not just the ones with errors or warnings. That makes the current script next to useless. I ran the script on my sites. It took me a while to realize that every file was listed. On my sites there are more than 10,000 php files. Scrolling through the entire list to see which files have errors is nearly impossible. I tried scrolling for one site, found a few errors that seemed harmless, and didn't finish a complete review. So I just decided to update a few sites and see if anything breaks.

So here are some suggestions for improving that script.

(1) Provide options before running the script to show only files with errors, or only files with errors or warnings, or show all files. (Although I don't think most people would use "all files". )

(2) After displaying the report, provide filters to show only files with errors, or warnings, or errors&warnings.

(3) If providing options or filters is difficult, change the script to only show files with errors or warnings. That's a better default than showing all files.

(4) Provide an option to download the report so I can run my own script to remove files with 0 errors and 0 warnings.