[Bug] Cannot run ./vendor/bin/ecs in 1.8

[co-codr]

Sylius-Standard version: 1.8.9
PHP: 7.3 or 7.4

How to reproduce:

Clone https://github.com/Sylius/Sylius-Standard
Checkout branch 1.8
Run composer install
Run ./vendor/bin/ecs

Error in console:

[ERROR] in_array() expects parameter 2 to be array, null given

Possible fixes:

• Upgrade to symplify/easy-coding-standard:v^9.0

The problem is in vendor/symplify/easy-coding-standard/src/Yaml/CheckerServiceParametersShifter.php constructor where serviceKeywords comes NULL instead of empty array.
After further investigation found out that in symfony/dependency-injection:4.4.19 the serviceKeywords has changed from a property to a constant in this commit.

A patch fix can be to change lines 72-73 in vendor/symplify/easy-coding-standard/src/Yaml/CheckerServiceParametersShifter.php to:

    $serviceKeywordsProperty = (new ReflectionClass(YamlFileLoader::class))
            ->getConstant('SERVICE_KEYWORDS');

I will try to push a fix to symplify/easy-coding-standard repo as well deprecated-packages/symplify#3017.
I think same issue might occur in 1.9 as well.

[co-codr]

Did not agree creating a 8.x branch in simplify, so the only solution is to upgrade to symplify/easy-coding-standard:v^9.0

[Zales0123]

Thank you for the investigation! 🎉 As far as I see, it would also require upgrading sylius-labs/coding-standard to ^4.0. Do you think you would be able to open a PR?