MDL-57775 xmlrpc: Test webservice_xmlrpc_client request encoding

The patch wraps the underlying xmlrpc_encode_request() call into a
standalone method that can be then unit-tested.

webservice/xmlrpc/lib.php

@@ -73,16 +73,7 @@ class webservice_xmlrpc_client {
             $this->serverurl->param('wstoken', $this->token);
         }
 
-        // Set output options.
-        $outputoptions = array(
-            'encoding' => 'utf-8',
-            'escaping' => 'markup',
-        );
-
-        // Encode the request.
-        // See MDL-53962 - needed for backwards compatibility on <= 3.0
-        $params = array_values($params);
-        $request = xmlrpc_encode_request($functionname, $params, $outputoptions);
+        $request = $this->encode_request($functionname, $params);
 
         // Set the headers.
         $headers = array(
@@ -103,4 +94,24 @@ class webservice_xmlrpc_client {
 
         return $result;
     }
+
+    /**
+     * Generates XML for a method request.
+     *
+     * @param string $functionname Name of the method to call.
+     * @param mixed $params Method parameters compatible with the method signature.
+     * @return string
+     */
+    protected function encode_request($functionname, $params) {
+
+        $outputoptions = array(
+            'encoding' => 'utf-8',
+            'escaping' => 'markup',
+        );
+
+        // See MDL-53962 - needed for backwards compatibility on <= 3.0.
+        $params = array_values($params);
+
+        return xmlrpc_encode_request($functionname, $params, $outputoptions);
+    }
 }

webservice/xmlrpc/tests/lib_test.php

@@ -88,6 +88,27 @@ class webservice_xmlrpc_test extends advanced_testcase {
         $this->expectException('moodle_exception');
         $client->call('testfunction');
     }
+
+    /**
+     * Test the XML-RPC request encoding.
+     */
+    public function test_encode_request() {
+
+        $client = new webservice_xmlrpc_client_mock('/webservice/xmlrpc/server.php', 'anytoken');
+
+        // Encode the request with the proper encoding and escaping options.
+        $xml = $client->encode_request('do_it', ['foo' => '<bar>ŠČŘŽÝÁÍÉ</bar>']);
+
+        // Assert that decoding with explicit encoding will work. This appeared
+        // to fail if the markup escaping was not set.
+        $this->assertEquals(['<bar>ŠČŘŽÝÁÍÉ</bar>'], xmlrpc_decode($xml, 'UTF-8'));
+
+        // Our experiments show that even with default/implicit encoding,
+        // requests encoded with markup escaping set are also decoded
+        // correctly. This is known to be used in some servers so we test it
+        // here, too.
+        $this->assertEquals(['<bar>ŠČŘŽÝÁÍÉ</bar>'], xmlrpc_decode($xml));
+    }
 }
 
 /**
@@ -137,4 +158,15 @@ class webservice_xmlrpc_client_mock extends webservice_xmlrpc_client {
 
         return $result;
     }
+
+    /**
+     * Allows to test the request encoding.
+     *
+     * @param string $functionname Name of the method to call.
+     * @param mixed $params Method parameters compatible with the method signature.
+     * @return string
+     */
+    public function encode_request($functionname, $params) {
+        return parent::encode_request($functionname, $params);
+    }
 }