I'm browsing through all failures on the php 8 run at the moment and see if I can fix or file separate issues for them.

Errors related to PHPUnit 9.3:

• TestCase::at() is deprecated. We would need to migrate away from it (the replacement is compatible with older PHPUnit versions, so this can be done separately)
• the PHPUnit bridge is not compatible, due to trying to use PHPUnit\TextUI\Exception
• assertDirectoryNotExists is deprecated in favor of assertDirectoryDoesNotExist. the bridge might provide a polyfill for the new method for older PHPUnit versions.
• Support for using expectException() with PHPUnit\Framework\Error\Warning is deprecated and will be removed in PHPUnit 10. Use expectWarning() instead.

Errors related to PHP 8:

• doctrine/annotations is currently broken due to changes in the tokens for namespaces. This is being worked on in Doctrine so this will be solved.
• Symfony\Component\Cache\Tests\Adapter\MemcachedAdapterTest and Symfony\Component\Cache\Tests\Simple\MemcachedCacheTextModeTest fail because the exception message for undefined class constants changed.
• Symfony\Component\ExpressionLanguage\Tests\Node\GetAttrNodeTest::testEvaluate fails because of an incompatibility with named arguments (probably using call_user_fun_array with an associative array)
• Symfony\Component\Filesystem\Tests\FilesystemTest fails with a TypeError on wrong mode. The tests should probably be skipped.
• Symfony\Component\Yaml\Tests\DumperTest::testSpecifications has a failure

Thanks for the overview. I can look into the individual issues in the upcoming days, but nevertheless I think that we can merge this PR already. It improves the php 8 CI from "completely broken" to "just a little broken". 😃

A few notes:

TestCase::at() is deprecated.

➡️ #37780

assertDirectoryNotExists is deprecated in favor of assertDirectoryDoesNotExist. the bridge might provide a polyfill for the new method for older PHPUnit versions.

It does already:

It does already:

then that's even easier. We can migrate to use the new method everywhere.

But this polyfill is weird. It never calls the parent implementation.

But this polyfill is weird. It never calls the parent implementation.

That's because PhpUnitBridge patches the trait directly into the TestCase class.

Also related to php 8: We still see the message Method ReflectionParameter::getClass() is deprecated frequently. As far as I can tell, we would need to backport #36975 to the 3.4 branch if we wanted to fix them.

Thank you @derrabus.

• doctrine/annotations is currently broken due to changes in the tokens for namespaces. This is being worked on in Doctrine so this will be solved.

for reference, this is now solved.