ConfigTranslationViewListUiTest is a WTB test in the Functional namespace

Good to know for any further conversions!

Should we update \Drupal\datetime\Tests\DateTestBase in this issue too? That also has the trigger_error after the namespace.

And \Drupal\views\Tests\Wizard\WizardTestBase

And what about base classes that don't implement setUp() like these
\Drupal\views\Tests\Plugin\PluginTestBase
\Drupal\views\Tests\Handler\HandlerTestBase

I guess implement setUp just to add the trigger_error?

yep let's do them all in this issue.

Here we go

I would expect other classes to potentially do similar kind of stuff in the constructor, so I'm wondering whether we should do the same here.

The advantage of using the constructor would be to have it really explicit, unlike with the setup() method, which is basically in the middle of nowhere and potentially harder to see.

I agree with @dawehner. The constructor makes it hard to miss and very specific. Patch moves the messages to a constructor.

Adding tags to make sure we don't forget these. Not changing the title yet to wait for more opinions..

+1 to adding a constructor with the deprecation

+1 for the constructor. Also, setUp() will get called multiple times so the trigger_error would get called multiple times too, which seems a little redundant.

+++ b/core/modules/views/src/Tests/Handler/HandlerTestBase.php
@@ -11,4 +10,13 @@
+    @trigger_error('\Drupal\views\Tests\Handler\HandlerTestBase is deprecated in Drupal 8.4.0 and will be removed before Drupal 9.0.0. Instead, use \Drupal\Tests\views\Functional\ViewTestBase', E_USER_DEPRECATED);

would be nice to use the __NAMESPACE__ pattern consistently

other then that, this looks good to me.

Fixed the namespace thing.

Seems we forgot this one: #2865992: Convert Datetime module Views tests to Kerneltest tough. I did another search and it's the only one missed I think.

Removing title and documentation tags. Title was updated and I just updated the documentation on this.

Patch looks good, doc changes look good and I think we have a consensus on how to handle this. Nice!

+++ b/core/modules/views/src/Tests/Handler/HandlerTestBase.php
@@ -16,7 +16,7 @@
-    @trigger_error('\Drupal\views\Tests\Handler\HandlerTestBase is deprecated in Drupal 8.4.0 and will be removed before Drupal 9.0.0. Instead, use \Drupal\Tests\views\Functional\ViewTestBase', E_USER_DEPRECATED);
+    @trigger_error(__NAMESPACE__ . '\HandlerTestBase is deprecated in Drupal 8.4.0 and will be removed before Drupal 9.0.0. Instead, use \Drupal\Tests\views\Functional\ViewTestBase', E_USER_DEPRECATED);

+++ b/core/modules/datetime/src/Tests/Views/DateTimeHandlerTestBase.php
@@ -43,6 +41,15 @@
+    @trigger_error(__NAMESPACE__ . '\DateTimeHandlerTestBase is deprecated in Drupal 8.4.0 and will be removed before Drupal 9.0.0. Instead, use \Drupal\Tests\BrowserTestBase', E_USER_DEPRECATED);

What about using static::class here?

static::class will be the late-static binding class name not the base class that we are deprecating; it's basically the same as get_called_class().

What about __CLASS__ then?

oh well you could have also used self::class

Because: If you use the constructor to throw a deprecation error in a phpunit-based test, and you use the phpunit tool with --group or --filter, you end up with a triggered error for every class that was initially discovered, not just the ones you ran.

That would mean that it would be no problem to trigger it in the constructor for simpletests as they're not run via phpunit right?

I for one would like the most ideal solution for the PHPUnit tests as that's the future and adapt to what's possible for Simpletest. If we're going to differ on solution for Simpletest: do we have a reason for not adding the trigger_error calls in the constructor?

It won't tell us that if we move it to setUp() or the constructor.

This alone makes the move back to right after the namespace worth it.

Good catch on the ConfigTranslationViewListUiTest, will try and find out if we have more of these. It's on my radar and I'll post this in the view_ui conversion issue and handle the conversion or follow-up there.

With the extensive research and history of the issue it's ready for RTBC I think.

@Mile23 was just about to ask for the title update - nice! But also the issue summary needs updating and the followup created.

Just commented on #2747167: Convert first part of web tests of views_ui on the follow-up issue here, that should cover it right?

Committed and pushed d284ae8 to 8.4.x and 9717b3a to 8.3.x. Thanks!