\Drupal\Tests\migrate\Kernel\Plugin\MigrationDirectoryTest uses @expectedDeprecationMessage

I think you might find that the annotation parser used is quite loose so it just finds @expectedDeprecation and it works just fine...

Hmmm nope - it's just ignoring the expectedDeprecation completely. It needs the @legacy but there's other stuff not happening when @expectedDeprecation is stuff. My guess is that this is a bug with Symfony and how the deprecation stuff works when process isolation is on as it is in KernelTestBase.

Well actually if you fix it to use @expectedDeprecation then it works as expected - the test currently fails cause the message has been updated to include the change record but the question is why is the @group legacy enough...

Here's a patch.

It is a bit sad that it cannot use an explicit API like PHPUnit does now. Otherwise this would have been detected already.

Yep, setExpectedDeprecation() would've been better.

Well, I'm quite sure that there is a reason: \Symfony\Bridge\PhpUnit\DeprecationErrorHandler::register needs to run before the actual test is executed, which is the place, where you can just parse annotations and not look at the actual code.

@Wim Leers I guess that might be nice. Considering phpunit mock objects now do the @trigger_error() thing there might be scope to add this to PHPUnit. See https://github.com/sebastianbergmann/phpunit-mock-objects/issues/271

The test passes because it's annotated @group legacy, and then the annotation is ignored. That's why it says:

Legacy deprecation notices (6)

After the patch you don't get this message, and you just get a passing test.

Therefore, RTBC.

Moving to 8.7.x because it's a test improvement.

Committed 79cb8c4 and pushed to 8.8.x. Thanks!