UnitTest: Add unit test for categories attribute

test/test_data/categories_test.ics

@@ -0,0 +1,27 @@
+BEGIN:VCALENDAR
+METHOD:PUBLISH
+PRODID:-//Moodle Pty Ltd//NONSGML Moodle Version 2019111802//EN
+VERSION:2.0
+BEGIN:VEVENT
+UID:3014@lms.itum.mrt.ac.lk
+SUMMARY:Lecture 2
+DESCRIPTION:
+CLASS:PUBLIC
+LAST-MODIFIED:20201110T094221Z
+DTSTAMP:20201110T095626Z
+DTSTART:20201117T073000Z
+DTEND:20201117T093000Z
+CATEGORIES:In19-S04-IT2403
+END:VEVENT
+BEGIN:VEVENT
+UID:3003@lms.itum.mrt.ac.lk
+SUMMARY:Week 2 (18/11/2020)
+DESCRIPTION:If Password ask you can give the following:Password: it2406-MC
+CLASS:PUBLIC
+LAST-MODIFIED:20201110T062311Z
+DTSTAMP:20201110T095626Z
+DTSTART:20201118T021500Z
+DTEND:20201118T041500Z
+CATEGORIES:In19-S04-IT2406,In19-S04-IT2405
+END:VEVENT
+END:VCALENDAR

test/test_icalevents.py

@@ -249,3 +249,11 @@ class ICalEventsTests(unittest.TestCase):
 
         self.assertEqual(events[2].created, None)
         self.assertEqual(events[2].last_modified, None)
+
+    def test_event_categories(self):
+        ical = "test/test_data/categories_test.ics"
+        start = date(2020, 11, 10)
+        end = date(2020, 11, 19)
+        events = icalevents.events(url=None, file=ical, start=start, end=end)
+        self.assertEqual(events[0].categories, ["In19-S04-IT2403"], "event 1 is not equal")
+        self.assertEqual(events[1].categories, ["In19-S04-IT2406", "In19-S04-IT2405"], "event 2 is not equal")