MDL-76055 libraries: Autoload phpxmlrpc and verify it works

Also, we can now safely remove Autoloader.php, because
Moodle PSR-4 autoloader has taken control, so document
and test it too.

lib/classes/component.php

@@ -108,6 +108,7 @@ class core_component {
         'ZipStream' => 'lib/zipstream/src/',
         'MyCLabs\\Enum' => 'lib/php-enum/src',
         'Psr\\Http\\Message' => 'lib/http-message/src',
+        'PhpXmlRpc' => 'lib/phpxmlrpc',
     );
 
     /**

lib/phpxmlrpc/Autoloader.php

@@ -1,36 +0,0 @@
-<?php
-
-namespace PhpXmlRpc;
-
-/**
- * In the unlikely event that you are not using Composer to manage class autoloading, here's an autoloader for this lib.
- * For usage, see any file in the demo/client directory
- */
-class Autoloader
-{
-    /**
-     * Registers PhpXmlRpc\Autoloader as an SPL autoloader.
-     *
-     * @param bool $prepend Whether to prepend the autoloader or not.
-     */
-    public static function register($prepend = false)
-    {
-        spl_autoload_register(array(__CLASS__, 'autoload'), true, $prepend);
-    }
-
-    /**
-     * Handles autoloading of classes.
-     *
-     * @param string $class A class name.
-     */
-    public static function autoload($class)
-    {
-        if (0 !== strpos($class, 'PhpXmlRpc\\')) {
-            return;
-        }
-
-        if (is_file($file = __DIR__ . str_replace(array('PhpXmlRpc\\', '\\'), '/', $class).'.php')) {
-            require $file;
-        }
-    }
-}

lib/phpxmlrpc/readme_moodle.txt

@@ -11,6 +11,8 @@ To update:
 - Download or checkout it.
 - Delete the contents on the lib/phpxmlrpc directory (but this file) completely.
 - Copy the /src directory contents of the library to lib/phpxmlrpc.
+- Remove the following files:
+  - Autoloader.php
 - Edit this file and update the release and commit details below.
 - Edit lib/thirdpartylibs.xml and update the information details too.
 

lib/tests/phpxmlrpc_test.php

@@ -0,0 +1,57 @@
+<?php
+// This file is part of Moodle - http://moodle.org/
+//
+// Moodle is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// Moodle is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with Moodle.  If not, see <http://www.gnu.org/licenses/>.
+
+namespace core;
+
+use PhpXmlRpc\Client;
+use PhpXmlRpc\Request;
+use PhpXmlRpc\Response;
+use PhpXmlRpc\Server;
+use PhpXmlRpc\Value;
+
+/**
+ * phpxmlrpc library unit tests.
+ *
+ * @package   core
+ * @category  test
+ * @copyright 2022 onwards Eloy Lafuente (stronk7) {@link https://stronk7.com}
+ * @license   https://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
+ */
+class phpxmlrpc_test extends \basic_testcase {
+
+    /**
+     * Ensure PhpXmlRpc availability.
+     *
+     * This may seem silly, sure it is. But it's a good way to verify
+     * that the Moodle PSR-4 autoloader is working ok.
+     *
+     * @coversNothing
+     */
+    public function test_phpxmlrpc_availability() {
+        // All these classes need to be at hand.
+        $this->assertInstanceOf(\PhpXmlRpc\Client::class, new Client('https://example.com'));
+        $this->assertInstanceOf(\PhpXmlRpc\Request::class, new Request(''));
+        $this->assertInstanceOf(\PhpXmlRpc\Response::class, new Response(''));
+        $this->assertInstanceOf(\PhpXmlRpc\Server::class, new Server());
+        $this->assertInstanceOf(\PhpXmlRpc\Value::class, new Value());
+
+        // Worth checking that we have removed this.
+        $this->assertFileDoesNotExist(__DIR__ . '/../phpxmlrpc/Autoloader.php');
+
+        // We cannnot live without our beloved readme.
+        $this->assertFileExists(__DIR__ . '/../phpxmlrpc/readme_moodle.txt');
+    }
+}