1.1.00

convex/typing.ts

@@ -22,6 +22,11 @@ export const startTyping = mutation({
     const userTyping = existing.find((t) => t.userId === args.userId);
 
     if (userTyping) {
+      // Refreshing an existing row — the cleanup scheduled from the
+      // original insert is still pending, so don't pile another copy
+      // onto the scheduler. The audit flagged the old code (schedule
+      // on every heartbeat) as spamming cleanExpired tasks that all
+      // did the same work.
       await ctx.db.patch(userTyping._id, { expiresAt });
     } else {
       await ctx.db.insert("typingIndicators", {
@@ -30,9 +35,9 @@ export const startTyping = mutation({
         username: args.username,
         expiresAt,
       });
+      await ctx.scheduler.runAfter(TYPING_TTL_MS, internal.typing.cleanExpired, {});
     }
 
-    await ctx.scheduler.runAfter(TYPING_TTL_MS, internal.typing.cleanExpired, {});
     return null;
   },
 });
@@ -93,11 +98,15 @@ export const cleanExpired = internalMutation({
   returns: v.null(),
   handler: async (ctx) => {
     const now = Date.now();
-    const expired = await ctx.db.query("typingIndicators").collect();
+    // Range-scan the by_expires_at index instead of collecting the whole
+    // table, so cleanup cost scales with number of *expired* rows rather
+    // than total typing activity across every channel.
+    const expired = await ctx.db
+      .query("typingIndicators")
+      .withIndex("by_expires_at", (q) => q.lte("expiresAt", now))
+      .collect();
     for (const t of expired) {
-      if (t.expiresAt <= now) {
-        await ctx.db.delete(t._id);
-      }
+      await ctx.db.delete(t._id);
     }
     return null;
   },