adr-example VS PHP Code Sniffer

Adding to the above link a full ADR Example - https://github.com/pmjones/adr-example

Yes, as an example, the First Application's business logic (not that it's much) doesn't tie itself to the framework, as one example. Odan's Slim Skeleton, ADR Example (yes, I know you are the author), and the Aura Payload example class can be seen as other examples.

ADR (as opposed to MVC) - direct link - example

https://github.com/pmjones/adr-example - Follow up example to the above. ADR is an alternative to MVC

More on ADR (like MVC) - https://github.com/pmjones/adr-example

Another option, to me and speaking to the OP as an alternative, it is simpler to add some Data Mappers/Repositories to abstract away the Database code. Good examples is the sample ADR application, Payload library example, Slim 3 First Application, or this Slim 4 Skeleton application

Simple example of a MVC/ADR (Action-Domain-Responder, similar to MVC) system - https://github.com/pmjones/adr-example

Call your class (which doesn't look like a controller anymore...), then, output it to your HTML or JSON renderer, based on the check. You can do this in a class (or 2 - look up ADR - https://github.com/pmjones/adr-example) or in the router.

PHP Insights supports sniffs from PHP CodeSniffer and fixers from PHP CS Fixer. This allows you to add any sniff or fixer as long as it implements PHP_CodeSniffer\Sniffs\Sniff or PhpCsFixer\Fixer\FixerInterface.

I don’t know why but that link keeps reloading the page over and over. This one works for me: https://github.com/squizlabs/PHP_CodeSniffer/issues/3932

PHP_CodeSniffer is a widely-used tool for enforcing coding standards in PHP. It checks the code against a set of predefined coding standards (such as PSR-12, PSR-2, and many others) and provides reports with violations and recommendations for improvement. Documentation: You can find more information about PHP_CodeSniffer and its usage in the official documentation: PHP_CodeSniffer Repository

While you're at it, also include code-style checkers like phpcs, phpmd and/or php-cs-fixer

See https://github.com/squizlabs/PHP_CodeSniffer

If you are well-versed in programming then you might wanna take a look at PHPCompatibility. It will scan your codebase at different PHP version rulesets to point out code that needs upgrading. You will be needing PHPCS for this.

PHP code sniffer