Fix compatibility with PHP 8.1

[W0rma]

Q	A
Bug fix?	no
New feature?	no
Doc updated	no
BC breaks?	no
Deprecations?	no
Tests pass?	yes
Fixed tickets
License	MIT

Run tests against PHP 8.1 and fix deprecation warning because of deprecated Serializeable interface (https://wiki.php.net/rfc/phase_out_serializable)

[W0rma]

The failing "tests-coverage" pipeline seems to be unrelated to this PR

[goetas]

thanks!

[alexander-schranz]

Hi,

I'm currently testing @sulu against current dev dependencies. In this case I did find out that the change of the jms/metadata between the current master and 2.5.1 does break serialization of our Localization object.

On 2.5.1 it runs correctly and on 3e1dc95 with this change it fails:

Does somebody understand why this is now happening. I do not see any error here in the code provided by @W0rma.

/cc @goetas do you have any idea how this change could affect this?

[goetas]

@alexander-schranz can it be becase this https://github.com/schmittjoh/serializer/blob/master/src/Metadata/PropertyMetadata.php#L213 does not call the parent serialization method?

[alexander-schranz]

@goetas Think we need also there add a __serialize and __unserialize method or what do you think?

[goetas]

this seems a very subtle change that will require a major release of jms/metadata. Since /src/Metadata/PropertyMetadata.php extends the base PropertyMetadata class, php will call __serialize ignoring the serialize method present in the child class.

[W0rma]

@goetas Should we bump the min PHP version to 7.4 in the new major release? This way we could already stop implementing the deprecated Serializable interface because the magic methods __serialize() and __unserialize() will be recognized automatically (https://wiki.php.net/rfc/custom_object_serialization).

Downside of this approach might be that we need a new major release for jms/serializer as well.

WDYT?

[goetas]

I think that we can bump the minimum version to 7.4.

Downside of this approach might be that we need a new major release for jms/serializer as well.

Why so? i think that we can still implement Serializable in the jms/serializer library and there still support php 7.2.

The main advantage I see of doing so is that other projects using jms/metadata can drop old php versions, for jms/serializer still want to keep 7.2 as minimum version requirement.

[goetas]

#105 implements a backward compatible version of this change