add tests, fix linter errors

ical.js

@@ -298,9 +298,9 @@ const dateParameter = function (name) {
         const vTimezone =
           Object.values(stackItemWithTimeZone).find(({type}) => type === 'VTIMEZONE');
 
-        // if the VTIMEZONE contains multiple TZIDs, use the last one in order
-        const normalizedTzId = vTimezone ? 
-          Array.isArray(vTimezone.tzid) ? vTimezone.tzid[vTimezone.tzid.length - 1] : vTimezone.tzid :
+        // If the VTIMEZONE contains multiple TZIDs, use the last one in order
+        const normalizedTzId = vTimezone ?
+          (Array.isArray(vTimezone.tzid) ? vTimezone.tzid[vTimezone.tzid.length - 1] : vTimezone.tzid) :
           null;
 
         newDate = normalizedTzId && moment.tz.zone(normalizedTzId) ?

test/test.js

@@ -983,6 +983,22 @@ vows
           assert.equal(topic.start.tz, 'Europe/Berlin');
         }
       }
+    },
+    'with test_with_multiple_tzids_in_vtimezone.ics': {
+      topic() {
+        return ical.parseFile('./test/test_with_multiple_tzids_in_vtimezone.ics');
+      },
+      'using a vtimezone with multiple timezone': {
+        topic(events) {
+          return _.select(_.values(events), x => {
+            return x.uid === '[email protected]';
+          })[0];
+        },
+        'has a start'(topic) {
+          assert.equal(topic.start.toJSON(), '2024-06-27T07:00:00.000Z');
+          assert.equal(topic.end.toJSON(), '2024-06-28T06:00:00.000Z');
+        }
+      }
     }
   })
   .export(module);

test/test_with_multiple_tzids_in_vtimezone.ics

@@ -0,0 +1,46 @@
+BEGIN:VCALENDAR
+VERSION:2.0
+PRODID:-//Hathaway Elementary School - ECPv6.3.3//NONSGML v1.0//EN
+CALSCALE:GREGORIAN
+METHOD:PUBLISH
+X-WR-CALNAME:Hathaway Elementary School
+X-ORIGINAL-URL:https://www.washougal.k12.wa.us/hathaway
+X-WR-CALDESC:Events for Hathaway Elementary School
+REFRESH-INTERVAL;VALUE=DURATION:PT1H
+X-Robots-Tag:noindex
+X-PUBLISHED-TTL:PT1H
+BEGIN:VTIMEZONE
+TZID:Africa/Abidjan
+BEGIN:STANDARD
+TZOFFSETFROM:+0000
+TZOFFSETTO:+0000
+TZNAME:GMT
+DTSTART:20240101T000000
+END:STANDARD
+TZID:America/Los_Angeles
+BEGIN:DAYLIGHT
+TZOFFSETFROM:-0800
+TZOFFSETTO:-0700
+TZNAME:PDT
+DTSTART:20240310T100000
+END:DAYLIGHT
+BEGIN:STANDARD
+TZOFFSETFROM:-0700
+TZOFFSETTO:-0800
+TZNAME:PST
+DTSTART:20241103T090000
+END:STANDARD
+END:VTIMEZONE
+BEGIN:VEVENT
+DTSTART:20240627T000000
+DTEND:20240627T230000
+DTSTAMP:20240222T162327
+CREATED:20231129T014844Z
+LAST-MODIFIED:20240222T184259Z
+UID:[email protected]
+SUMMARY:Possible Snow Makeup Day
+DESCRIPTION:This day is a snow makeup day\, and will be added back to the calendar if needed. If we do not have any snow closure\, this is a non-attendance day for students.  \nFor a list of all calendar related closures and important dates\, please visit our calendar page at https://www.washougal.k12.wa.us/calendar/
+URL:https://www.washougal.k12.wa.us/hathaway/event/possible-snow-makeup-day/
+CATEGORIES:School Events
+END:VEVENT
+END:VCALENDAR