Issue #3269097 by tedbow, phenaproxima: Add test coverage to determine if...

Issue #3269097 by tedbow, phenaproxima: Add test coverage to determine if global functions are reloaded when updates are applied

package_manager/tests/fixtures/updated_module/1.0.0/updated_module.module

+<?php
+
+/**
+ * @file
+ * Contains global functions for testing updates to a .module file.
+ */
+
+/**
+ * A test function to test if global functions are reloaded during an update.
+ *
+ * @return string
+ */
+function _updated_module_global1(): string {
+  return "pre-update-value";
+}

package_manager/tests/fixtures/updated_module/1.1.0/updated_module.module

+<?php
+
+/**
+ * @file
+ * Contains global functions for testing updates to a .module file.
+ */
+
+/**
+ * A test function to test if global functions are reloaded during an update.
+ *
+ * @return string
+ */
+function _updated_module_global1(): string {
+  return "post-update-value";
+}
+
+/**
+ * A test function to test if a new global function will be available after an update.
+ */
+function _updated_module_global2(): void {
+}

package_manager/tests/modules/package_manager_test_api/package_manager_test_api.services.yml

+services:
+  package_manager_test_api.system_change_recorder:
+    class: Drupal\package_manager_test_api\SystemChangeRecorder
+    arguments:
+      - '@package_manager.path_locator'
+      - '@state'
+    tags:
+      - { name: event_subscriber }

package_manager/tests/modules/package_manager_test_api/src/SystemChangeRecorder.php

+<?php
+
+namespace Drupal\package_manager_test_api;
+
+use Drupal\Core\State\StateInterface;
+use Drupal\package_manager\Event\PostApplyEvent;
+use Drupal\package_manager\Event\PostDestroyEvent;
+use Drupal\package_manager\Event\PreApplyEvent;
+use Drupal\package_manager\Event\StageEvent;
+use Drupal\package_manager\PathLocator;
+use Symfony\Component\EventDispatcher\EventSubscriberInterface;
+
+/**
+ * Defines a service for checking system changes during an update.
+ */
+class SystemChangeRecorder implements EventSubscriberInterface {
+
+  /**
+   * The path locator service.
+   *
+   * @var \Drupal\package_manager\PathLocator
+   */
+  private $pathLocator;
+
+  /**
+   * The state service.
+   *
+   * @var \Drupal\Core\State\StateInterface
+   */
+  private $state;
+
+  /**
+   * Constructs a SystemChangeRecorder object.
+   *
+   * @param \Drupal\package_manager\PathLocator $path_locator
+   *   The path locator service.
+   * @param \Drupal\Core\State\StateInterface $state
+   *   The state service.
+   */
+  public function __construct(PathLocator $path_locator, StateInterface $state) {
+    $this->pathLocator = $path_locator;
+    $this->state = $state;
+  }
+
+  /**
+   * Records aspects of system state at various points during an update.
+   *
+   * @param \Drupal\package_manager\Event\StageEvent $event
+   *   The stage event.
+   */
+  public function recordSystemState(StageEvent $event): void {
+    $results = [];
+
+    // Call a function in a loaded file to ensure it doesn't get reloaded after
+    // changes are applied.
+    $results['return value of existing global function'] = _updated_module_global1();
+
+    // Check if a new global function exists after changes are applied.
+    $results['new global function exists'] = function_exists('_update_module_global2') ? "exists" : "not exists";
+
+    $phase = $event instanceof PreApplyEvent ? 'pre' : 'post';
+    $this->state->set("system_changes:$phase", $results);
+  }
+
+  /**
+   * Writes the results of ::recordSystemState() to file.
+   *
+   * Build tests do not have access to the Drupal API, so write the results to
+   * a file so the build test can check them.
+   */
+  public function writeResultsToFile(): void {
+    $results = [
+      'pre' => $this->state->get('system_changes:pre'),
+      'post' => $this->state->get('system_changes:post'),
+    ];
+    $dir = $this->pathLocator->getProjectRoot();
+    file_put_contents("$dir/system_changes.json", json_encode($results));
+  }
+
+  /**
+   * {@inheritdoc}
+   */
+  public static function getSubscribedEvents() {
+    return [
+      PreApplyEvent::class => 'recordSystemState',
+      PostApplyEvent::class => 'recordSystemState',
+      PostDestroyEvent::class => 'writeResultsToFile',
+    ];
+  }
+
+}

package_manager/tests/src/Build/PackageUpdateTest.php

@@ -43,6 +43,7 @@ class PackageUpdateTest extends TemplateProjectTestBase {
         'web/modules/contrib/alpha/composer.json',
         'web/modules/contrib/updated_module/composer.json',
         'bravo.txt',
+        "system_changes.json",
       ],
     ]);
     $this->visit("/package-manager-test-api?$query");
@@ -65,6 +66,21 @@ class PackageUpdateTest extends TemplateProjectTestBase {
     // created this file.
     // @see \Drupal\updated_module\PostApplySubscriber::postApply()
     $this->assertSame('Bravo!', $file_contents['bravo.txt']);
+
+    $results = json_decode($file_contents['system_changes.json'], TRUE);
+    $expected_pre_apply_results = [
+      'return value of existing global function' => 'pre-update-value',
+      'new global function exists' => 'not exists',
+    ];
+    $this->assertSame($expected_pre_apply_results, $results['pre']);
+
+    $expected_post_apply_results = [
+      // Existing functions will still use the pre-update version.
+      'return value of existing global function' => 'pre-update-value',
+      // New functions that were added in .module files will not be available.
+      'new global function exists' => 'not exists',
+    ];
+    $this->assertSame($expected_post_apply_results, $results['post']);
   }
 
   /**