MDL-23545 question: XML import/export add category description

question/format/xml/tests/xmlformat_test.php

@@ -1583,4 +1583,40 @@ END;
         $this->assertEquals('/myfolder/', $file->filepath);
         $this->assertEquals(6,            $file->size);
     }
+
+    public function test_create_dummy_question() {
+
+        $testobject = new mock_qformat_xml();
+        $categoryname = 'name1';
+        $categoryinfo = new stdClass();
+        $categoryinfo->info = 'info1';
+        $categoryinfo->infoformat = 'infoformat1';
+        $dummyquestion = $testobject->mock_create_dummy_question_representing_category($categoryname, $categoryinfo);
+
+        $this->assertEquals('category', $dummyquestion->qtype);
+        $this->assertEquals($categoryname, $dummyquestion->category);
+        $this->assertEquals($categoryinfo->info, $dummyquestion->info);
+        $this->assertEquals($categoryinfo->infoformat, $dummyquestion->infoformat);
+        $this->assertEquals('Switch category to ' . $categoryname, $dummyquestion->name);
+        $this->assertEquals(0, $dummyquestion->id);
+        $this->assertEquals('', $dummyquestion->questiontextformat);
+        $this->assertEquals(0, $dummyquestion->contextid);
+    }
+}
+
+/**
+ * Class mock_qformat_xml exists only to enable testing of the create dummy question category.
+ * @package    qformat_xml
+ * @copyright  2018 The Open University
+ * @license    http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
+ */
+class mock_qformat_xml extends qformat_xml {
+    /**
+     * Make public an otherwise protected function.
+     * @param string $categoryname the name of the category
+     * @param object $categoryinfo description of the category
+     */
+    public function mock_create_dummy_question_representing_category(string $categoryname, $categoryinfo) {
+        return $this->create_dummy_question_representing_category($categoryname, $categoryinfo);
+    }
 }