Bust the flair caches after 30mins

Group profile data and the groups a user has publicised will be removed from the cache 30mins after retrieval.

There may be some benefits to caching the group profiles for longer than the group memberships but for now they're naively busted after the same 30mins.

src/components/views/elements/Flair.js

@@ -29,6 +29,9 @@ const BULK_REQUEST_DEBOUNCE_MS = 200;
 // If true, flair can function and we should keep sending requests for groups and avatars.
 let groupSupport = true;
 
+const USER_GROUPS_CACHE_BUST_MS = 1800000; // 30 mins
+const GROUP_PROFILES_CACHE_BUST_MS = 1800000; // 30 mins
+
 // TODO: Cache-busting based on time. (The server won't inform us of membership changes.)
 // This applies to userGroups and groupProfiles. We can provide a slightly better UX by
 // cache-busting when the current user joins/leaves a group.
@@ -69,7 +72,9 @@ function getPublicisedGroupsCached(matrixClient, userId) {
         usersPending[userId].reject = reject;
     }).then((groups) => {
         userGroups[userId] = groups;
-        // TODO: Reset cache at this point
+        setTimeout(() => {
+            delete userGroups[userId];
+        }, USER_GROUPS_CACHE_BUST_MS);
         return userGroups[userId];
     }).catch((err) => {
         throw err;
@@ -126,6 +131,9 @@ async function getGroupProfileCached(matrixClient, groupId) {
         groupId,
         avatarUrl: profile.avatar_url,
     };
+    setTimeout(() => {
+        delete groupProfiles[groupId];
+    }, GROUP_PROFILES_CACHE_BUST_MS);
 
     return groupProfiles[groupId];
 }