fix: display hints are sometimes wrong

packages/@webex/plugin-meetings/src/locus-info/index.ts

@@ -518,7 +518,7 @@ export default class LocusInfo extends EventsScope {
     this.updateControls(locus.controls, locus.self);
     this.updateLocusUrl(locus.url, ControlsUtils.isMainSessionDTO(locus));
     this.updateFullState(locus.fullState);
-    this.updateMeetingInfo(locus.info);
+    this.updateMeetingInfo(locus.info, locus.self);
     this.updateEmbeddedApps(locus.embeddedApps);
     // self and participants generate sipUrl for 1:1 meeting
     this.updateSelf(locus.self);
@@ -2491,9 +2491,19 @@ export default class LocusInfo extends EventsScope {
    */
   updateMeetingInfo(info: object, self?: object) {
     const roles = self ? SelfUtils.getRoles(self) : this.parsedLocus.self?.roles || [];
-    if ((info && !isEqual(this.info, info)) || (!isEqual(this.roles, roles) && info)) {
-      const isJoined = SelfUtils.isJoined(self || this.parsedLocus.self);
-      const parsedInfo = InfoUtils.getInfos(this.parsedLocus.info, info, roles, isJoined);
+    const isJoined = SelfUtils.isJoined(self || this.parsedLocus.self);
+
+    // The parsed userDisplayHints depend on info, roles and isJoined, so we must recompute
+    // whenever any of them changes. A common case is self transitioning to JOINED via a delta
+    // that doesn't carry an info section - in that case we fall back to the previously stored
+    // info so the hints get reparsed with the new joined state (e.g. VIEW_THE_PARTICIPANT_LIST).
+    const infoToParse = info || this.info;
+    const infoChanged = info && !isEqual(this.info, info);
+    const rolesChanged = !isEqual(this.roles, roles);
+    const isJoinedChanged = SelfUtils.isJoined(this.parsedLocus.self) !== isJoined;
+
+    if (infoToParse && (infoChanged || rolesChanged || isJoinedChanged)) {
+      const parsedInfo = InfoUtils.getInfos(this.parsedLocus.info, infoToParse, roles, isJoined);
 
       if (parsedInfo.updates.isLocked) {
         this.emitScoped(
@@ -2516,7 +2526,7 @@ export default class LocusInfo extends EventsScope {
         );
       }
 
-      this.info = info;
+      this.info = infoToParse;
       this.parsedLocus.info = parsedInfo.current;
       // Parses the info and adds necessary values
       this.updateMeeting(parsedInfo.current);

packages/@webex/plugin-meetings/test/unit/spec/locus-info/index.js

@@ -2846,6 +2846,10 @@ describe('plugin-meetings', () => {
 
         let expectedMeeting;
 
+        // simulate that updateSelf has been called previously (as happens in production)
+        // so that parsedLocus.self reflects the joined state
+        locusInfo.parsedLocus.self = {state: 'JOINED'};
+
         /*
         When the event is triggered, it is required that the meeting has already
         been updated. This is why the meeting is being checked within the stubbed event emitter
@@ -2997,6 +3001,46 @@ describe('plugin-meetings', () => {
         // since self is not passed to updateMeetingInfo, MEETING_INFO_UPDATED should be triggered with isIntializing: true
         checkMeetingInfoUpdatedCalledForRoles(true, {isInitializing: true});
       });
+
+      // joined-section hints (like ROSTER_IN_MEETING) are filtered out while not joined, so they
+      // are a good proxy for verifying that userDisplayHints get recomputed on a join transition
+      [
+        {
+          name: 'the JOINED delta carries the info section',
+          getSecondInfo: (info) => info,
+        },
+        {
+          name: 'the JOINED delta omits the info section (falls back to stored info)',
+          getSecondInfo: () => undefined,
+        },
+      ].forEach(({name, getSecondInfo}) => {
+        it(`recomputes userDisplayHints when self transitions to JOINED with unchanged roles and ${name}`, () => {
+          const info = cloneDeep(meetingInfo); // joined: ['ROSTER_IN_MEETING', 'LOCK_STATUS_UNLOCKED']
+
+          const notJoinedSelf = cloneDeep(self);
+          notJoinedSelf.state = 'IDLE';
+          notJoinedSelf.controls.role.roles = [];
+
+          const joinedSelf = cloneDeep(self);
+          joinedSelf.state = 'JOINED';
+          joinedSelf.controls.role.roles = [];
+
+          sinon.stub(locusInfo, 'emitScoped');
+
+          // first update while not joined: joined-section hints are filtered out
+          locusInfo.updateMeetingInfo(info, notJoinedSelf);
+          assert.notInclude(locusInfo.parsedLocus.info.userDisplayHints, 'ROSTER_IN_MEETING');
+          assert.notInclude(locusInfo.parsedLocus.info.userDisplayHints, 'LOCK_STATUS_UNLOCKED');
+
+          // self transitions to JOINED - info and roles are unchanged
+          locusInfo.updateMeetingInfo(getSecondInfo(info), joinedSelf);
+
+          // the hints must be recomputed with the new joined state
+          assert.include(locusInfo.parsedLocus.info.userDisplayHints, 'ROSTER_IN_MEETING');
+          assert.include(locusInfo.parsedLocus.info.userDisplayHints, 'LOCK_STATUS_UNLOCKED');
+          checkMeetingInfoUpdatedCalled(true, {isInitializing: false});
+        });
+      });
     });
 
     describe('#updateMediaShares', () => {