Phan
Phan is a static analyzer for PHP
...Phan looks for common issues and will verify type compatibility on various operations when type information is available or can be deduced. Phan has a good (but not comprehensive) understanding of flow control and can track values in a few use cases (e.g. arrays, integers, and strings). With Phan installed, you'll want to create a .phan/config.php file in your project to tell Phan how to analyze your source code. Phan 5 depends on PHP 7.2+ with the php-ast extension (1.0.16+ is preferred) and supports analyzing PHP version 7.0-8.1 syntax. ...