From 8a5563445dcf65dcfe267c200027fe8ebea93bec Mon Sep 17 00:00:00 2001
From: Jake Dallimore <jake@moodle.com>
Date: Thu, 12 Jan 2023 11:28:37 +0800
Subject: [PATCH] MDL-76862 user: Unit test for setting user home page
 preferences

---
 user/tests/externallib_test.php | 32 ++++++++++++++++++++++++++++++++
 1 file changed, 32 insertions(+)

diff --git a/user/tests/externallib_test.php b/user/tests/externallib_test.php
index 95812a41bab..cbabc9d824b 100644
--- a/user/tests/externallib_test.php
+++ b/user/tests/externallib_test.php
@@ -1675,4 +1675,36 @@ class externallib_test extends externallib_advanced_testcase {
             $this->assertEquals('email', $user['extrafields'][0]['name']);
         }
     }
+
+    /**
+     * Test verifying that update_user_preferences prevents changes to the default homepage for other users.
+     */
+    public function test_update_user_preferences_homepage_permission_callback() {
+        global $DB;
+        $this->resetAfterTest();
+
+        $user = self::getDataGenerator()->create_user();
+        $this->setUser($user);
+        $adminuser = get_admin();
+
+        // Allow user selection of the default homepage via preferences.
+        set_config('defaulthomepage', HOMEPAGE_USER);
+
+        // Try to save another user's home page preference which uses the permissioncallback.
+        $preferences = [
+            [
+                'name' => 'user_home_page_preference',
+                'value' => '3',
+                'userid' => $adminuser->id,
+            ]
+        ];
+        $result = core_user_external::set_user_preferences($preferences);
+        $result = \external_api::clean_returnvalue(core_user_external::set_user_preferences_returns(), $result);
+        $this->assertCount(1, $result['warnings']);
+        $this->assertCount(0, $result['saved']);
+
+        // Verify no change to the preference, checking from DB to avoid cache.
+        $this->assertEquals(null, $DB->get_field('user_preferences', 'value',
+            ['userid' => $adminuser->id, 'name' => 'user_home_page_preference']));
+    }
 }