[Symfony 6] Symfony\Component\HttpKernel\Event\KernelEvent::isMasterRequest() is deprecated, use isMainRequest() instead

Should we combine this with #3209617: [Symfony 6] Symfony\Component\HttpFoundation\RequestStack::getMasterRequest() is deprecated, use getMainRequest() instead? Seems like it'll depend on the subclass used in the other issue.

But because the classes are final, we can't extend them and if we just replace them then existing type checks won't work:

I can hear class_alias() calling from across the hills. It means we'll have to copy HttpKernel to our own version, but it should handle the replacement angle.

This sort of thing, completely untested patch.

--- Commands Executed ---
core/scripts/dev/commit-code-check.sh --drupalci
Return Code: 1
--- Output ---
/var/www/html/core/lib/Drupal/Core/Http/KernelEvent.php:18:21 - Unknown word (Schussek)

CSpell: failed

Now with some basic test coverage for the forward compatibility layer.

Test failures are the new deprecation kicking in, this ought to fix hopefully.

1. Made this 5.3 since the new method will be available then.
2. Yep. Tried to tidy this up a bit.
3. Yes probably although I'm failing to to get the test to pass locally, trying a 'hit and hope' with DrupalCI.
4. As with #2.

Fixing the cs issues.

Is the MASTER_REQUEST const still not deprecated?

Feel like I've seen the deprecation testing blow up like this before, but not seeing what the problem is with the test.

I double checked that that class_alias was working in the legacy test (just in case we were somehow loading Symfony's KernelEvent), but it wasn't that, so something to do with the deprecation listener itself I think - but didn't get far enough. Unit test is better anyway though and seems happy.

The patch looks good. Just 2 nitpicks.

1. +++ b/core/lib/Drupal/Core/Http/KernelEvent.php
   @@ -0,0 +1,90 @@
   +// @codingStandardsIgnoreFile
   +// cspell:disable
   +
   +
   +namespace Drupal\Core\Http;
   

   Nitpick: A single empty line is enough.

2. +++ b/core/lib/Drupal/Core/Http/KernelEvent.php
   @@ -0,0 +1,90 @@
   +/*
   

   Nitpick: The slash is not needed here.

Addressing #22.

The added class is extending the Symfony class that in version 5.3 will throw a deprecation message.
The added class is being added by a class_alias call in the class DrupalKernel.
There is testing for class_alias call and the deprecation message.
All calls to the deprecated method have been replaced.
Added a CR and updated the IS.
For me it is RTBC.

All Symfony 6 related issues are critical.

+++ b/core/lib/Drupal/Core/DrupalKernel.php
@@ -39,6 +40,9 @@
+// @todo: remove this class alias once Drupal is running Symfony 5.3 or higher.
+class_alias(KernelEvent::class, 'Symfony\Component\HttpKernel\Event\KernelEvent', TRUE);

+++ b/core/tests/Drupal/KernelTests/Core/DrupalKernel/DrupalKernelTest.php
@@ -58,6 +59,18 @@ protected function getTestKernel(Request $request, array $modules_enabled = NULL
+   * @todo: remove this test once Drupal is using Symfony 5.3 or higher.

As per https://www.drupal.org/docs/develop/standards/api-documentation-and-comm...

Usually, a corresponding Drupal.org issue should be created for the @todo and referenced in it.

These should IMHO point to #3197482: Update Drupal 10 to depend on Symfony 5.4 (as a stepping stone to Symfony 6, for deprecation checking support). That would make it easier to find the corresponding issue and to find the todos referencing it as well.

Added @todo reference issue link

The point of @gabor has been addressed.
Back to RTBC.

+++ b/core/lib/Drupal/Core/DrupalKernel.php
@@ -39,6 +40,8 @@
+class_alias(KernelEvent::class, 'Symfony\Component\HttpKernel\Event\KernelEvent', TRUE);

I've felt for a while we should have a core/class_aliases.php which should be included by composer as this would mean that our aliases are decoupled from including this class. This has a big benefit of meaning that in unit tests we'll use our class even when DrupalKernel has not be included. I think we should open a follow-up to move this to such a file.

Committed and pushed 85ee5e164b to 9.3.x and b1fd5e7cc9 to 9.2.x. Thanks!

diff --git a/core/lib/Drupal/Core/DrupalKernel.php b/core/lib/Drupal/Core/DrupalKernel.php
index 6b9807e18b..d9af456bbd 100644
--- a/core/lib/Drupal/Core/DrupalKernel.php
+++ b/core/lib/Drupal/Core/DrupalKernel.php
@@ -40,8 +40,8 @@
 use TYPO3\PharStreamWrapper\Behavior as PharStreamWrapperBehavior;
 use TYPO3\PharStreamWrapper\PharStreamWrapper;
 
-// @todo: remove this class alias once Drupal is running Symfony 5.3 or higher.
-// @see https://www.drupal.org/project/drupal/issues/3197482
+// @todo https://www.drupal.org/project/drupal/issues/3197482 Remove this class
+//   alias once Drupal is running Symfony 5.3 or higher.
 class_alias(KernelEvent::class, 'Symfony\Component\HttpKernel\Event\KernelEvent', TRUE);
 
 /**
diff --git a/core/tests/Drupal/KernelTests/Core/DrupalKernel/DrupalKernelTest.php b/core/tests/Drupal/KernelTests/Core/DrupalKernel/DrupalKernelTest.php
index b139933ea2..056e0e82e3 100644
--- a/core/tests/Drupal/KernelTests/Core/DrupalKernel/DrupalKernelTest.php
+++ b/core/tests/Drupal/KernelTests/Core/DrupalKernel/DrupalKernelTest.php
@@ -62,8 +62,8 @@ protected function getTestKernel(Request $request, array $modules_enabled = NULL
   /**
    * Tests KernelEvent class_alias() override.
    *
-   * @todo: remove this test once Drupal is using Symfony 5.3 or higher.
-   * @see https://www.drupal.org/project/drupal/issues/3197482
+   * @todo https://www.drupal.org/project/drupal/issues/3197482 Remove this test
+   *   once Drupal is using Symfony 5.3 or higher.
    */
   public function testKernelEvent() {
     $request = Request::createFromGlobals();

removed the @see's on commit - the link can go in the @todo just fine.

Created the follow-up #3214234: Add core/class_aliases.php