CI: Introduce PHP compatibility check

[Wirone]

Inspired by this finding, bug introduced in #7616, reproduced here - we have invalid return type in code and none of the tools caught this. I thought this is because we run PHPStan on 8.3 which then assumes it's valid return type, but I modified dev-tools/composer.json, allowed PHP 7.4 and checked on it, but PHPStan still did not report it, even on max level. I believe this is a bug (CC: @ondrejmirtes), but anyway I thought maybe it's a good idea to introduce PHPCompatibility check, which is more focused on differences between PHP versions.

This is a draft and CI will fail, because we need to decide how we want to handle dynamic usages of PHP consts etc. I believe that sniffs should not report these problems if constant is used in if condition, like:

if (\defined('T_READONLY')) {
    // Skip readonly classes for PHP 8.2+
    $acceptTypes[] = T_READONLY;
}

but this is separate problem that should be addressed and fixed in long-term (CC: @jrfnl).

PS. There is 10.x-dev as 9.99.0 constraint because 10.x development version has more checks, but at the same time is not compatible with phpcompatibility/phpcompatibility-symfony which handles Symfony polyfills. We've been using this setup for months in GetResponse and it helped us with migration from 7.4 to 8.2, so I assume it as safe enough 🙂.

[coveralls]

coverage: 94.769%. remained the same
when pulling 9cdb005 on Wirone:codito/phpcompatibility
into ea01071 on PHP-CS-Fixer:master.

[ondrejmirtes]

Please don't cc me on other repositories. If you want, you can isolate the bug, reproduce it and report it properly on PHPStan's issue tracker.

[keradus]

+0.5

@Wirone , is this compat package still maintained?
is last release 5 years old ? ref

[Wirone]

@keradus it's maintained, but not 9.x 🙂. Please see the PS in PR's description. For wider context you can look at my Twitter thread, it sparked PHPCompatibility/PHPCompatibility#1480 which then was implemented in PHPCompatibility/PHPCompatibility#1730. So yeah, this is actively developed (last commit month ago, maybe holidays 😉).

[keradus]

it's maintained, but not 9.x 🙂

last release 5 years ago sounds to me like not maintained fully. I understand there is ongoing development to make 10.x, but it's never officially release for last 5 years. At least 10.0-alpha.1 or sth..., just dev-master isn't best versioning/release cycle

[keradus]

thank you @Wirone

[Wirone]

it's maintained, but not 9.x 🙂

last release 5 years ago sounds to me like not maintained fully. I understand there is ongoing development to make 10.x, but it's never officially release for last 5 years. At least 10.0-alpha.1 or sth..., just dev-master isn't best versioning/release cycle

@jrfnl did you consider tagging a 10.* release, even alpha/beta/RC? What's the status of phpcompatibility/phpcompatibility-symfony? Thanks in advance for the feedback 🙂.

[keradus]

I aksed them in their repo earlier - PHPCompatibility/PHPCompatibility#1312 (comment) .

I know for lot of ppl monitoring questions in each repo is not manageable and they focus on their repos for communication.

[Wirone]

@keradus *her 😉. And from my experience she does not have a problem with mentioning outside of PHPCompatibility org.

[coveralls]

coverage: 94.965%. remained the same
when pulling a333eb9 on Wirone:codito/phpcompatibility
into ea13be1 on PHP-CS-Fixer:master.