MDL-51495 calendar: Unit test to get an individual course event

If is user requests a single event on a course via the web service they should be able to retrieve it.

calendar/tests/externallib_test.php

@@ -363,6 +363,13 @@ class core_calendar_externallib_testcase extends externallib_advanced_testcase {
         $events = external_api::clean_returnvalue(core_calendar_external::get_calendar_events_returns(), $events);
         $this->assertEquals(1, count($events['events'])); // site.
         $this->assertEquals(0, count($events['warnings']));
+
+        // Try getting a course event by its id.
+        $paramevents = array ('eventids' => array($courseevent->id));
+        $events = core_calendar_external::get_calendar_events($paramevents, $options);
+        $events = external_api::clean_returnvalue(core_calendar_external::get_calendar_events_returns(), $events);
+        $this->assertEquals(1, count($events['events']));
+        $this->assertEquals(0, count($events['warnings']));
     }
 
     /**