Undefined variable: groups in \Drupal\views\Plugin\views\filter\FilterPluginBase::groupForm

Let's better define $group = []; by default

Patch in #2 still applies with fuzz, but should be rerolled for the testbot.

Rerolled. Please review.

Thank you for the reroll!

I added a beta phase evaluation to the issue summary.

Hm. Sounds like we are missing some test coverage here?

Test coverage for this specific error will be non-trivial, given that from what I can tell, there is currently zero coverage of any of these form methods. (Not that it wouldn't be valuable though.)

I filed a follow-up issue #2421023: Create tests for FilterPluginBase form methods to add tests. As I said above, it will be non-trivial, and since this is such an obvious bug fix, I don't think it need be blocked by that task.

git ac https://www.drupal.org/files/issues/undefined_variable-2339921-2.patch
  % Total    % Received % Xferd  Average Speed   Time    Time     Time  Current
                                 Dload  Upload   Total   Spent    Left  Speed
100   646  100   646    0     0   2201      0 --:--:-- --:--:-- --:--:--  2219
error: patch failed: core/modules/views/src/Plugin/views/filter/FilterPluginBase.php:749
error: core/modules/views/src/Plugin/views/filter/FilterPluginBase.php: patch does not apply

Adding some related issues.

Given the fact that there are tests see #2421023: Create tests for FilterPluginBase form methods perhaps we can test this.

An attempt to reproduce the error and write tests for it

While writing tests for this, i encountered this notice, Notice: Undefined index: #states in Drupal\views\Plugin\views\filter\FilterPluginBase->buildExposedFiltersGroupForm() Here is a fix for it.

Still seeing issue -> core 8.6.3

IMHO we should not

+++ b/core/modules/views_ui/src/Tests/FilterPluginBaseTest.php
@@ -0,0 +1,56 @@
+/**
+ * @file
+ * Contains \Drupal\views_ui\Tests\FilterPluginBaseTest.
+ */
+
+namespace Drupal\views_ui\Tests;
+
+/**
+ * Tests the FilterPluginBase class.
+ *
+ * @group views
+ * @see \Drupal\views\Plugin\views\filter\FilterPluginBase
+ */
+class FilterPluginBaseTest extends UITestBase {

a) Let's remove the @file comment

b) Extend \Drupal\Tests\views_ui\Functional\UITestBase instead and write a browser based test.

We have a test now though.

Searching for duplicates I found #3277134: Count Argument is null and it brings to fatal error when upgrading from PHP 7.4 to PHP 8.1 which is addressing the same problem. I am closing that one in favor of this earlier issue.

+++ b/core/modules/views/src/Plugin/views/filter/FilterPluginBase.php
@@ -992,15 +993,17 @@ protected function buildExposedFiltersGroupForm(&$form, FormStateInterface $form
+          if (isset($row['value'][$child]['#states']['visible'])) {

The change starting here is out of scope.

Closing #3277134: Count Argument is null and it brings to fatal error when upgrading from PHP 7.4 to PHP 8.1 as a duplicate.

Rerolled patch #32 in 9.5.x .

The Needs Review Queue Bot tested this issue. It either no longer applies to Drupal core, or fails the Drupal core commit checks. Therefore, this issue status is now "Needs work".

Apart from a re-roll or rebase, this issue may need more work to address feedback in the issue or MR comments. To progress an issue, incorporate this feedback as part of the process of updating the issue. This helps other contributors to know what is outstanding.

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I think patch in #50 is removing a bunch of stuff, added a MR bringing #32 up to date, it works for my use case.
Setting to NR to clarify what's left.

The Needs Review Queue Bot tested this issue.

While you are making the above changes, we recommend that you convert this patch to a merge request. Merge requests are preferred over patches. Be sure to hide the old patch files as well. (Converting an issue to a merge request without other contributions to the issue will not receive credit.)

Figured out how to reproduce this one, updating IS.

Funnily enough fixing this error starts throwing more:

Warning: Undefined array key "status" in Drupal\views\Plugin\views\filter\FilterPluginBase->acceptExposedInput() (line 1619 of core/modules/views/src/Plugin/views/filter/FilterPluginBase.php).
and
Warning: Undefined array key "status" in Drupal\views\Plugin\views\filter\FilterPluginBase->convertExposedInput() (line 1505 of core/modules/views/src/Plugin/views/filter/FilterPluginBase.php).

Test coverage appears here https://git.drupalcode.org/issue/drupal-2339921/-/jobs/7228657 I tried to find an existing test that maybe we could expand but this could be expanded on in the future maybe.

Code was seems straight forward and no objections

Going to mark

Committed 6419400 and pushed to 11.x. Thanks!
Committed ffcc4c3 and pushed to 11.3.x. Thanks!

This is causing new warnings in tests:

    Time: 00:04.728, Memory: 8.00 MB
    
    Filter Group Form (Drupal\Tests\views\Functional\FilterGroupForm)
     ✘ Filter group form empty
       ┐
       ├ Exception: Deprecated function: Using null as an array offset is deprecated, use an empty string instead
       ├ Drupal\views\Plugin\views\filter\FilterPluginBase->convertExposedInput()() (Line: 1510)

See https://git.drupalcode.org/issue/drupal-3463868/-/pipelines/702131/test_...

Reverted... we need to fix that.

I rebased the branch MR on top of 11.x so it should fail the same way as HEAD did.

I've fixed the MR up to not use NULLs as a value for $selected_group.

MR needs to be rebased against HEAD. Tests are failing because the 11.x commit for #3557585: Update to Composer 2.9.2 is missing.

Also, it might be a good idea for a follow up to document the params and and return type of FilterPluginBase::convertExposedInput().

Rebase came back green

lgtm

Second time lucky...

Committed and pushed b2c0b060da2 to 11.x and f1f4db7022c to 11.3.x. Thanks!