[Bug]: Deprecation notice due to inheritance validation

[luislard]

Description of the bug

I am checking if we can move one of our projects to PHP8.1 and I am getting a deprecation notice in wp-app-container see:

Deprecated: Return type of Inpsyde\App\EnvConfig::jsonSerialize() should either be compatible with JsonSerializable::jsonSerialize(): mixed, or the #[\ReturnTypeWillChange] attribute should be used to temporarily suppress the notice in /var/www/html/public/wp-content/mu-plugins/unilux-app-container/vendor/inpsyde/wp-app-container/src/EnvConfig.php on line 257

This error is documented in Backward Incompatible Changes

I tried to change the return type but it will fail in PHP7.* because the mixed return type was introduced in PHP8

As I can see we are trying to support PHP7 in the v3.x of this package -> inferred because of this

So we have 3 options: Create a new major v4 that only supports PHP >= 8.0 Stay in v3 but add the #[\ReturnTypeWillChange] to the method (easiest) Ignore the deprecation

Reproduction instructions

Use v3 of this package with PHP8.1

Expected behavior

Remove the deprecation notice

Environment info

ddev with PHP8.1

Relevant log output

No response

Additional context

No response

Code of Conduct

• [X] I agree to follow this project's Code of Conduct

[luislard]

I am trying to replicate the issue with Psalm, it seems that psalm has suppressed the error from happening: They have it documented in here, but they are removing it from the tests run? see here

Now will try to replicate the issue with PHPUnit, will let you know later

[luislard]

Tried to trigger the issue in PHPUnit.

I checked what happens if I remove the attribute in any of the files by PHPUnit itself and the PHPUnit suite didn't catch the error. See my test

I will just add the attribute in the required places.

[gmazzap]

PR merged.