Ignore missing legacy hook BC attributes (LegacyHook, LegacyRequirementsHook, LegacyModuleImplementsAlter)

.github/workflows/php.yml

@@ -128,6 +128,11 @@ jobs:
         run: |
           cd ~/drupal
           ./vendor/bin/phpstan analyze web/core/install.php --debug
+      - name: "Test legacy hook attribute stubs"
+        run: |
+          cp $GITHUB_WORKSPACE/tests/fixtures/integration/legacy-hook-attributes.php ~/drupal/legacy-hook-attributes.php
+          cd ~/drupal
+          ./vendor/bin/phpstan analyze legacy-hook-attributes.php --no-progress
       - name: "Test BrowserTestBase is autoloaded"
         run: |
           cd ~/drupal
@@ -200,6 +205,11 @@ jobs:
         run: |
           cd ~/drupal
           ./vendor/bin/phpstan analyze web/core/install.php --debug
+      - name: "Test legacy hook attribute stubs"
+        run: |
+          cp $GITHUB_WORKSPACE/tests/fixtures/integration/legacy-hook-attributes.php ~/drupal/legacy-hook-attributes.php
+          cd ~/drupal
+          ./vendor/bin/phpstan analyze legacy-hook-attributes.php --no-progress
       - name: "Test no crash"
         run: |
           cd ~/drupal

extension.neon

@@ -1,6 +1,16 @@
 parameters:
 	bootstrapFiles:
 		- drupal-autoloader.php
+	ignoreErrors:
+		-
+			message: '#^Attribute class Drupal\\Core\\Hook\\Attribute\\LegacyHook does not exist\.$#'
+			reportUnmatched: false
+		-
+			message: '#^Attribute class Drupal\\Core\\Hook\\Attribute\\LegacyRequirementsHook does not exist\.$#'
+			reportUnmatched: false
+		-
+			message: '#^Attribute class Drupal\\Core\\Hook\\Attribute\\LegacyModuleImplementsAlter does not exist\.$#'
+			reportUnmatched: false
 	excludePaths:
 		- '*.api.php'
 		- '*/tests/fixtures/*.php'

tests/fixtures/integration/legacy-hook-attributes.php

@@ -0,0 +1,28 @@
+<?php
+
+declare(strict_types=1);
+
+/**
+ * Fixture for verifying LegacyHook, LegacyRequirementsHook, and
+ * LegacyModuleImplementsAlter attribute stubs are available regardless of
+ * installed Drupal version.
+ *
+ * These attributes were added at different minor versions and LegacyHook is
+ * being removed in Drupal 12. PHPStan should not report "class not found"
+ * errors when these attributes are used.
+ */
+
+use Drupal\Core\Hook\Attribute\LegacyHook;
+use Drupal\Core\Hook\Attribute\LegacyModuleImplementsAlter;
+use Drupal\Core\Hook\Attribute\LegacyRequirementsHook;
+
+#[LegacyHook]
+function phpstan_drupal_test_node_presave(): void {}
+
+#[LegacyRequirementsHook]
+function phpstan_drupal_test_requirements(string $phase): array {
+    return [];
+}
+
+#[LegacyModuleImplementsAlter]
+function phpstan_drupal_test_module_implements_alter(array &$implementations, string $hook): void {}