Create test addon

tests/Util/helloaddon/helloaddon.php

@@ -0,0 +1,29 @@
+<?php
+
+// SPDX-FileCopyrightText: 2010-2024 the Friendica project
+//
+// SPDX-License-Identifier: AGPL-3.0-or-later
+
+/**
+ * Name: Hello Addon
+ * Description: For testing purpose only
+ * Version: 1.0
+ * Author: Artur Weigandt <dont-mail-me@example.com>
+ */
+
+use Friendica\Core\Hook;
+
+function helloaddon_install()
+{
+	Hook::register('page_end', 'addon/helloaddon/helloaddon.php', 'helloaddon_page_end');
+}
+
+function helloaddon_uninstall()
+{
+	Hook::unregister('page_end', 'addon/helloaddon/helloaddon.php', 'helloaddon_page_end');
+}
+
+function helloaddon_page_end(&$html)
+{
+	$html .= '<p>Hello, World!</p>';
+}