Convert HandlerAllTest into a kernel test

1 nitpicky item. But how we have done other conversions think it should be included.

Thanks @Spokje

I repeated #4 and there is still a difference (but also see how much quicker the kernel test is):

Time: 00:11.982, Memory: 4.00 MB

There was 1 error:

1) Drupal\Tests\views\Functional\Handler\HandlerAllTest::testHandlers
This test printed output: int(35)

vs

Time: 00:02.926, Memory: 4.00 MB

There was 1 error:

1) Drupal\Tests\views\Kernel\Handler\HandlerAllTest::testHandlers
This test printed output: int(31)

Maybe we need some additional coverage to ensure all handlers in core are included?

Added some more modules

This test printed output: int(37)

Checked all modules that implement hook_views_data, think this get all of the ones that don't need extra handling or just reuse existing plugins...I think

Feedback appears to be addressed.

Do we need either a follow-up or some more work in here to make sure that adding modules with views handlers to core, but not to this test. would break either this test or another new test?

I think a follow-up to add a test coverage test is probably a good idea, the old test would not have caught new modules either so not a requirement for me, but useful to have.

Committed/pushed to 11.x and cherry-picked to 10.2.x, thanks!

Automatically closed - issue fixed for 2 weeks with no activity.