MDL-71242 core_course: Test the validation of the sort value

Adds new unit test, test_course_get_recent_courses_sort_validation(),
which is reponsible for testing the validation of the sort value in
course_get_recent_courses().

course/tests/courselib_test.php

@@ -5484,6 +5484,57 @@ public function test_course_get_recent_courses() {
         $this->assertArrayNotHasKey($courses[0]->id, $result);
     }
 
+    /**
+     * Test the validation of the sort value in course_get_recent_courses().
+     *
+     * @dataProvider course_get_recent_courses_sort_validation_provider
+     * @param string $sort The sort value
+     * @param string $expectedexceptionmsg The expected exception message
+     */
+    public function test_course_get_recent_courses_sort_validation(string $sort, string $expectedexceptionmsg) {
+        $this->resetAfterTest();
+
+        $user = $this->getDataGenerator()->create_user();
+
+        if (!empty($expectedexceptionmsg)) {
+            $this->expectException('invalid_parameter_exception');
+            $this->expectExceptionMessage($expectedexceptionmsg);
+        }
+        course_get_recent_courses($user->id, 0, 0, $sort);
+    }
+
+    /**
+     * Data provider for test_course_get_recent_courses_sort_validation().
+     *
+     * @return array
+     */
+    function course_get_recent_courses_sort_validation_provider() {
+        return [
+            'Invalid sort format (SQL injection attempt)' =>
+                [
+                    'shortname DESC LIMIT 1--',
+                    'Invalid structure of the sort parameter, allowed structure: fieldname [ASC|DESC].',
+                ],
+            'Sort uses \'sort by\' field that does not exist' =>
+                [
+                    'shortname DESC, xyz ASC',
+                    'Invalid field in the sort parameter, allowed fields: id, idnumber, summary, summaryformat, ' .
+                    'startdate, enddate, category, shortname, fullname, timeaccess, component, visible, ' .
+                    'showactivitydates, showcompletionconditions.',
+            ],
+            'Sort uses invalid value for the sorting direction' =>
+                [
+                    'shortname xyz, lastaccess',
+                    'Invalid sort direction in the sort parameter, allowed values: asc, desc.',
+                ],
+            'Valid sort format' =>
+                [
+                    'shortname asc, timeaccess',
+                    ''
+                ]
+        ];
+    }
+
     /**
      * Test the course_get_recent_courses function.
      */