From 1c04e650f743fac39d64b35b8f25c87ab8fe0f91 Mon Sep 17 00:00:00 2001
From: Pieter Frenssen <pieter@frenssen.be>
Date: Sun, 2 Aug 2020 14:59:08 +0300
Subject: [PATCH] Allow modules to alter access to group content entity
 operations.

---
 src/OgAccess.php                              |  19 +-
 tests/modules/og_test/og_test.module          |  25 +++
 tests/modules/og_test/og_test.permissions.yml |   3 +
 .../GroupContentOperationAccessAlterTest.php  | 179 ++++++++++++++++++
 4 files changed, 222 insertions(+), 4 deletions(-)
 create mode 100644 tests/modules/og_test/og_test.permissions.yml
 create mode 100644 tests/src/Kernel/Access/GroupContentOperationAccessAlterTest.php

diff --git a/src/OgAccess.php b/src/OgAccess.php
index 7a0b15356..9fd950aef 100644
--- a/src/OgAccess.php
+++ b/src/OgAccess.php
@@ -324,6 +324,8 @@ public function userAccessEntityOperation(string $operation, EntityInterface $en
    * {@inheritdoc}
    */
   public function userAccessGroupContentEntityOperation(string $operation, EntityInterface $group_entity, EntityInterface $group_content_entity, AccountInterface $user = NULL): AccessResultInterface {
+    $access_result = AccessResult::neutral();
+
     // Default to the current user.
     $user = $user ?: $this->accountProxy->getAccount();
 
@@ -350,9 +352,9 @@ public function userAccessGroupContentEntityOperation(string $operation, EntityI
 
     if ($permissions) {
       foreach ($permissions as $permission) {
-        $user_access = $this->userAccess($group_entity, $permission->getName(), $user);
-        if ($user_access->isAllowed()) {
-          return $user_access;
+        $access_result = $this->userAccess($group_entity, $permission->getName(), $user);
+        if ($access_result->isAllowed()) {
+          break;
         }
       }
     }
@@ -366,7 +368,16 @@ public function userAccessGroupContentEntityOperation(string $operation, EntityI
       $cacheable_metadata->addCacheContexts(['user']);
     }
 
-    return AccessResult::neutral()->addCacheableDependency($cacheable_metadata);
+    // Let modules alter the access result.
+    $context = [
+      'operation' => $operation,
+      'group' => $group_entity,
+      'group_content' => $group_content_entity,
+      'user' => $user,
+    ];
+    $this->moduleHandler->alter('og_user_access_entity_operation', $access_result, $cacheable_metadata, $context);
+
+    return $access_result->addCacheableDependency($cacheable_metadata);
   }
 
   /**
diff --git a/tests/modules/og_test/og_test.module b/tests/modules/og_test/og_test.module
index f2a14fc10..19b82ebc5 100644
--- a/tests/modules/og_test/og_test.module
+++ b/tests/modules/og_test/og_test.module
@@ -1,10 +1,15 @@
 <?php
 
+declare(strict_types = 1);
+
 /**
  * @file
  * Main functions and hook implementations of the OG Test module.
  */
 
+use Drupal\Core\Access\AccessResultAllowed;
+use Drupal\Core\Access\AccessResultInterface;
+use Drupal\Core\Cache\CacheableMetadata;
 use Drupal\Core\Entity\EntityInterface;
 use Drupal\og\Entity\OgRole;
 use Drupal\og\Og;
@@ -39,3 +44,23 @@ function og_test_entity_insert(EntityInterface $entity) {
     $membership->save();
   }
 }
+
+/**
+ * Implements hook_og_user_access_entity_operation_alter().
+ */
+function og_test_og_user_access_entity_operation_alter(AccessResultInterface &$access_result, CacheableMetadata &$cacheable_metadata, $context): void {
+  if (\Drupal::state()->get('og_test_group_content_entity_operation_access_alter', FALSE)) {
+    // Moderators should have access to edit and delete all comments in all
+    // groups.
+    /** @var \Drupal\Core\Session\AccountProxyInterface $user */
+    $user = $context['user'];
+    $group_content = $context['group_content'];
+
+    $is_comment = $group_content->getEntityTypeId() === 'comment';
+    $user_can_moderate_comments = $user->hasPermission('edit and delete comments in all groups');
+
+    if ($is_comment && $user_can_moderate_comments) {
+      $access_result = new AccessResultAllowed();
+    }
+  }
+}
diff --git a/tests/modules/og_test/og_test.permissions.yml b/tests/modules/og_test/og_test.permissions.yml
new file mode 100644
index 000000000..cbf42a419
--- /dev/null
+++ b/tests/modules/og_test/og_test.permissions.yml
@@ -0,0 +1,3 @@
+# A permission given to users who can moderate comments in all groups.
+edit and delete comments in all groups:
+  title: 'Moderate comments in all groups'
diff --git a/tests/src/Kernel/Access/GroupContentOperationAccessAlterTest.php b/tests/src/Kernel/Access/GroupContentOperationAccessAlterTest.php
new file mode 100644
index 000000000..3a6bd10e1
--- /dev/null
+++ b/tests/src/Kernel/Access/GroupContentOperationAccessAlterTest.php
@@ -0,0 +1,179 @@
+<?php
+
+declare(strict_types = 1);
+
+namespace Drupal\Tests\og\Kernel\Access;
+
+use Drupal\KernelTests\KernelTestBase;
+use Drupal\Tests\user\Traits\UserCreationTrait;
+use Drupal\comment\Entity\Comment;
+use Drupal\comment\Entity\CommentType;
+use Drupal\entity_test\Entity\EntityTest;
+use Drupal\og\Og;
+use Drupal\og\OgGroupAudienceHelperInterface;
+use Drupal\user\Entity\User;
+
+/**
+ * Test that access to group content operations can be altered.
+ *
+ * @coversDefaultClass \Drupal\og\OgAccess
+ * @group og
+ */
+class GroupContentOperationAccessAlterTest extends KernelTestBase {
+
+  use UserCreationTrait;
+
+  /**
+   * {@inheritdoc}
+   */
+  public static $modules = [
+    'comment',
+    'entity_test',
+    'field',
+    'og',
+    'og_test',
+    'system',
+    'user',
+  ];
+
+  /**
+   * The OG access service. This is the system under test.
+   *
+   * @var \Drupal\og\OgAccessInterface
+   */
+  protected $ogAccess;
+
+  /**
+   * A test user.
+   *
+   * @var \Drupal\user\UserInterface
+   */
+  protected $user;
+
+  /**
+   * A test group.
+   *
+   * @var \Drupal\entity_test\Entity\EntityTest
+   */
+  protected $group;
+
+  /**
+   * A test group content entity.
+   *
+   * @var \Drupal\comment\CommentInterface
+   */
+  protected $groupContent;
+
+  /**
+   * {@inheritdoc}
+   */
+  protected function setUp(): void {
+    parent::setUp();
+
+    $this->installEntitySchema('comment');
+    $this->installEntitySchema('entity_test');
+    $this->installEntitySchema('og_membership');
+    $this->installEntitySchema('user');
+    $this->installSchema('system', 'sequences');
+
+    $this->ogAccess = $this->container->get('og.access');
+
+    // Create a dummy user which will get UID 1. We cannot use this for testing
+    // since this user becomes the super administrator and is not suitable for
+    // testing access control.
+    User::create(['name' => $this->randomString()])->save();
+
+    // Create a test user with the 'moderator' role which has global permission
+    // to moderate comments in all groups, even ones they are not a member of.
+    $this->user = $this->createUser(['edit and delete comments in all groups']);
+
+    // Create the test group along with a user that serves as the group owner.
+    $group_bundle = mb_strtolower($this->randomMachineName());
+    $this->group = EntityTest::create([
+      'type' => $group_bundle,
+      'name' => $this->randomString(),
+      'user_id' => $this->createUser()->id(),
+    ]);
+    $this->group->save();
+
+    // Declare that the test entity type is a group type.
+    Og::groupTypeManager()->addGroup('entity_test', $group_bundle);
+
+    // Create a group content type.
+    CommentType::create([
+      'id' => 'comment',
+      'label' => 'Comment subscription',
+      'target_entity_type_id' => 'entity_test',
+    ])->save();
+    $settings = [
+      'field_storage_config' => [
+        'settings' => [
+          'target_type' => 'entity_test',
+        ],
+      ],
+    ];
+    Og::createField(OgGroupAudienceHelperInterface::DEFAULT_FIELD, 'comment', 'comment', $settings);
+
+    // Create a group content entity.
+    $values = [
+      'subject' => 'subscribe',
+      'comment_type' => 'comment',
+      'entity_id' => $this->group->id(),
+      'entity_type' => 'entity_test',
+      'field_name' => 'an_imaginary_field',
+      OgGroupAudienceHelperInterface::DEFAULT_FIELD => [['target_id' => $this->group->id()]],
+    ];
+    $this->groupContent = Comment::create($values);
+    $this->groupContent->save();
+  }
+
+  /**
+   * Tests that modules can alter group content entity operation access.
+   *
+   * This mimicks a use case where a moderator has access to edit and delete
+   * comments in all groups.
+   *
+   * @see \og_test_og_user_access_entity_operation_alter()
+   *
+   * @dataProvider groupContentEntityOperationAccessAlterHookTestProvider
+   */
+  public function testGroupContentEntityOperationAccessAlterHook(string $operation): void {
+    // Check that our test user doesn't have access to edit or delete comments
+    // in the group.
+    // This is the default behavior for users that are not a group member.
+    $this->assertFalse($this->userHasAccess($operation));
+
+    // Now enable our hook which will alter the group content entity operation
+    // access rules to allow moderators to edit and delete comments in all
+    // groups. Since our user is a moderator they should now have access.
+    \Drupal::state()->set('og_test_group_content_entity_operation_access_alter', TRUE);
+    $this->assertTrue($this->userHasAccess($operation));
+  }
+
+  /**
+   * Checks whether the test user has access to perform the entity operation.
+   *
+   * @param string $operation
+   *   The entity operation to check.
+   *
+   * @return bool
+   *   TRUE if the user has access, FALSE otherwise.
+   */
+  protected function userHasAccess(string $operation): bool {
+    return $this->ogAccess->userAccessGroupContentEntityOperation($operation, $this->group, $this->groupContent, $this->user)->isAllowed();
+  }
+
+  /**
+   * Provides test data for ::testGroupContentEntityOperationAccessAlterHook().
+   *
+   * @return string[][]
+   *   Test cases for the 'update' and 'delete' entity operations.
+   */
+  public function groupContentEntityOperationAccessAlterHookTestProvider(): array {
+    return [
+      ['update'],
+      ['delete'],
+    ];
+  }
+
+}