Add PHPStan to Magento static checks

[larsroettig]

Summary (*)

As the architecture team discussed at https://github.com/magento/architecture/pull/114 we should add PHPStan as developer composer dependencies.

How: composer require --dev phpstan/phpstan Add check to dev/tests/static/phpunit.xml.dist

Expected behaviour (*)

PHPStan run with the Magento static checks

Actual result (*)

Php Stan is not installed and does not run with the static checks

Examples (*)

Benefits

Following types of issues can be found in Magento codebase: the use of undefined class; call to undefined function; missing parent::__construct() call; passed arguments mismatch, etc.

Additional information

The Drupal people also picked up phpstan, read some insights https://glamanate.com/blog/writing-better-drupal-code-static-analysis-using-phpstan

Proposed solution

[magento-engcom-team]

Hi @larsroettig. Thank you for your report. To help us process this issue please make sure that you provided the following information:

• [x] Summary of the issue
• [x] Information on your environment
• [x] Steps to reproduce
• [x] Expected and actual results

Please make sure that the issue is reproducible on the vanilla Magento instance following Steps to reproduce. To deploy vanilla Magento instance on our environment, please, add a comment to the issue:

@magento-engcom-team give me 2.3-develop instance - upcoming 2.3.x release

For more details, please, review the Magento Contributor Assistant documentation.

@larsroettig do you confirm that you was able to reproduce the issue on vanilla Magento instance following steps to reproduce?

• [ ] yes
• [ ] no

[lenaorobei]

Additional details:

• Use level 0 (loosest one) check for now.
• Take into account - https://github.com/magento/magento2/blob/2.3-develop/dev/tests/static/phpunit.xml.dist#L34 and investigate the possibility to run against the whole codebase.
• Most important - fix findings 🙂

[ondrejmirtes]

Looking forward to closely observe this :) The main challenge when getting level 0 to run is to configure autoloading properly - sometimes projects rely on weird autoloading rules or custom autoloader. Most commonly, there's problem with PHPUnit testcases - they have to be present at least in autoload-dev too.

This is important to get right:

* Have class definitions in files by themselves, not mix them with any side-effects (like code below the class definition that runs when the class is autoloaded)

• Do the same with functions.
• Classes can be autoloaded with Composer out of the box, or you can provide your own autoloader PHP files with the -a CLI option.
• Functions have to be included using the autoload_files option in phpstan.neon (or files in Composer).

[shochdoerfer]

You might want to follow our work regarding Magento support for PHPStan here until there's an official extension ;)

[lenaorobei]

PHPStan was added to Magento https://github.com/magento/magento2/blob/2.4-develop/composer.json#L95