Datelist doesn't respect #required_error

Attached patch against Drupal 10.1.x

Please include an interdiff and how the previous patch didn’t apply to receive credit for rerolling

This has been blocked on tests for awhile, so added a test based on the patch in #15.

Ideally we wouldn't introduce a new test class for this and just include it in DatelistElementFormTest, but I wasn't sure about the best approach for this. Happy for suggestions

Some small phpcs things still need to be fixed in the last patch. The test looks good at first glance, personally I'm not that worried about adding new test classes in kernel tests.

sorry for the wrong patch #22

Looks like a random fail. Seeing back to NR and requing tests

Are the changes to

testDatelistElement changes needed? It passes with or without the fix.

Those changes are there to assert that you still get the correct error when you have not included #required_error.

It would be passing without the patch because that was the only error that could be displayed. Now that we support #required_error we need to assert the existing error still displays when you don't have #required_error on the element.

Ah thanks for that @DanielVeza don't mind marking then

+++ b/core/tests/Drupal/KernelTests/Core/Datetime/DatelistElementRequiredError.php
@@ -0,0 +1,87 @@
+class DatelistElementRequiredError extends KernelTestBase implements FormInterface {

Can we reuse the existing test here? we could use a data provider to pass required error and expected error.

Would also be good to get a red/green set of patches showing the test catches the bug.