fix: exclude meeting instance date from parent rrule

Excludes the original meeting instance date (before the meeting was
updated) from the recurring parent meeting's rrule. Previously, TB was
using the updated meeting time which would not properly exclude the
meeting instance if it was moved forward into the future.

Author: nicholaschiang

components/calendar/weekly-display.tsx

@@ -74,9 +74,13 @@ function WeeklyDisplay({
   const [viewing, setViewing] = useState<Meeting>();
   const [now, setNow] = useState<Date>(new Date());
 
+  const originalEditing = useRef<Meeting>(initialEditData);
   const updateMeetingRemote = useCallback(async (updated: Meeting) => {
     const url = `/api/meetings/${updated.id}`;
-    const { data } = await axios.put<MeetingJSON>(url, updated.toJSON());
+    const { data } = await axios.put<MeetingJSON>(url, {
+      ...updated.toJSON(),
+      options: { original: originalEditing.current.toJSON() },
+    });
     return Meeting.fromJSON(data);
   }, []);
 
@@ -94,6 +98,11 @@ function WeeklyDisplay({
     error: editError,
   } = useSingle<Meeting>(initialEditData, updateMeetingRemote, mutateMeeting);
 
+  useEffect(() => {
+    if (editing.id !== originalEditing.current.id)
+      originalEditing.current = editing;
+  }, [editing]);
+
   const headerRef = useRef<HTMLDivElement>(null);
   const timesRef = useRef<HTMLDivElement>(null);
   const rowsRef = useRef<HTMLDivElement>(null);

lib/api/routes/meetings/update.ts

@@ -20,9 +20,12 @@ import updateZoom from 'lib/api/update/zoom';
 import verifyAuth from 'lib/api/verify/auth';
 import verifyBody from 'lib/api/verify/body';
 import verifyDocExists from 'lib/api/verify/doc-exists';
+import verifyOptions from 'lib/api/verify/options';
+import verifyRecurIncludesTime from 'lib/api/verify/recur-includes-time';
 import verifySubjectsCanBeTutored from 'lib/api/verify/subjects-can-be-tutored';
 import verifyTimeInAvailability from 'lib/api/verify/time-in-availability';
 
+export type UpdateMeetingOptions = { original: MeetingJSON };
 export type UpdateMeetingRes = MeetingJSON;
 
 export default async function updateMeeting(
@@ -35,6 +38,9 @@ export default async function updateMeeting(
       isMeetingJSON,
       Meeting
     );
+    const options = verifyOptions<UpdateMeetingOptions>(req.body, {
+      original: body.toJSON(),
+    });
 
     const [matchDoc, meetingDoc] = await Promise.all([
       verifyDocExists('matches', body.match.id),
@@ -62,7 +68,7 @@ export default async function updateMeeting(
     // - Admins can change 'approved' to 'pending' or 'logged'.
     // - Meeting people can change 'pending' to 'logged'.
 
-    if (original.time.recur) {
+    if (original.id !== body.id && original.time.recur) {
       // User is updating a recurring meeting. By default, we only update this
       // meeting and all future meetings:
       // 1. Create a new recurring meeting using this meeting's data.
@@ -72,16 +78,24 @@ export default async function updateMeeting(
       body.id = '';
       body.parentId = undefined;
       body.venue = await createZoom(body, people);
+
+      // Ensure that the `until` value isn't before the `time.from` value (which
+      // would prevent *any* meeting instances from being calculated).
+      body.time.recur = verifyRecurIncludesTime(body.time);
       body.time.last = getLastTime(body.time);
 
       const meeting = await createMeetingDoc(body);
       await createMeetingSearchObj(meeting);
 
-      // TODO: We need to know the start time of the meeting instance before it
+      // TODO: We need to know the start date of the meeting instance before it
       // was updated. Otherwise, we can't properly exclude it from the original.
       original.time.recur = RRule.optionsToString({
         ...RRule.parseString(original.time.recur),
-        until: body.time.from, // TODO: Replace with time before update.
+        until: new Date(
+          new Date(options.original.time.from).getFullYear(),
+          new Date(options.original.time.from).getMonth(),
+          new Date(options.original.time.from).getDate()
+        ),
       });
       original.time.last = getLastTime(original.time);
 

lib/api/verify/options.ts

@@ -0,0 +1,5 @@
+// TODO: Verify that the values at each key in `body.options` matches the
+// required data type in `T`. Only use values that are valid.
+export default function verifyOptions<T>(body: unknown, fallback: T): T {
+  return { ...fallback, ...(body as { options: T }).options };
+}

lib/api/verify/recur-includes-time.ts

@@ -0,0 +1,13 @@
+import { RRule } from 'rrule';
+
+import { Timeslot } from 'lib/model';
+
+// Ensure that the `until` value of an RRule isn't before the `time.from` value
+// (which would prevent *any* meeting instances from being calculated).
+export default function verifyRecurIncludesTime(time: Timeslot): string {
+  const { until, ...options } = RRule.parseString(time.recur);
+  if (!until || until >= time.to) return time.recur;
+  // If the `until` value is before the timeslot end, we set it to the timeslot
+  // end. Note that we could instead set it to the timeslot start (same effect).
+  return RRule.optionsToString({ ...options, until: time.to });
+}