v4: what comes into a live list goes where its date puts it — a dump edited into a category stayed out of the index's feed of it until a reload, and a dump or a playlist made public went on top of the others' lists as if just posted. The index's feed now takes a dump edited into its scope, and orders the dumps that arrive by date, as the server pages them; a created playlist goes by date in the profile's and /playlists' lists, a new one first as before. Both use withByDate (utils/feed/pagedList.ts), which leaves an item older than every one loaded to a later page. The search runs again after a reconnection, for every page of dumps loaded, with its users and playlists; it shares refetchPages with usePagedList's resync. injectDump's doc said a private dump is never broadcast, while its poster gets it.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

src/hooks/dump/useDumpListSync.ts

@@ -9,11 +9,11 @@ import { useEffect, useLayoutEffect, useRef } from "react";
 import type { Dump } from "../../../shared/dump.ts";
 import { useWS, useWSEvent } from "../ws/useWS.ts";
 import { insertAt, usePositionMemory } from "../feed/usePositionMemory.ts";
+import { withByDate } from "../../utils/feed/pagedList.ts";
 
 /**
  * Passed to {@link useDumpListSync} by the lists that need more than edits and
- * deletions. The index's feed adds no dump through it, since it merges
- * `WSContext`'s `recentDumps` itself.
+ * deletions.
  */
 export interface DumpListSyncOptions {
   /**
@@ -32,23 +32,11 @@ export interface DumpListSyncOptions {
    * Also adds a dump `belongs` accepts that the list never held, where the
    * newest-first order puts it among the dumps loaded: a new one first. One
    * older than all of them is left to the next pages. For the lists sorted by
-   * `createdAt`, as a profile's dumps.
+   * `createdAt`: the index's feed, a profile's dumps, the followed users'.
    */
   addNew?: boolean;
 }
 
-/**
- * Returns `list` with `dump` before the first dump posted earlier, or as is
- * when none was: the dump belongs to a later page.
- */
-function insertByDate(list: Dump[], dump: Dump): Dump[] {
-  if (list.length === 0) return [dump];
-  const idx = list.findIndex((d) =>
-    d.createdAt.getTime() < dump.createdAt.getTime()
-  );
-  return idx === -1 ? list : insertAt(list, dump, idx);
-}
-
 /**
  * Applies the socket's dump, comment and user events to `items`, the loaded
  * list, which `setDumps` updates. A deleted dump is removed, an edited one is
@@ -96,7 +84,7 @@ export function useDumpListSync(
       }
       if (!accepted) return prev;
       if (oldIdx !== undefined) return insertAt(prev, dump, oldIdx);
-      return addNew ? insertByDate(prev, dump) : prev;
+      return addNew ? withByDate(prev, dump) : prev;
     });
   });
 

src/hooks/feed/usePagedList.ts

@@ -13,6 +13,7 @@ import {
   firstPage,
   mapItems,
   type PagedList,
+  refetchPages,
   restoredList,
 } from "../../utils/feed/pagedList.ts";
 import type { FeedCacheEntry } from "./useFeedCache.ts";
@@ -114,22 +115,8 @@ export function usePagedList<T extends { id: string }>(
   const resync = useCallback(() => {
     const { list, fetchPage } = latestRef.current;
     if (!list) return;
-    const pages = Array.from({ length: list.page }, (_, i) => i + 1);
-    Promise.all(pages.map((page) => fetchPage(page)))
-      .then((results) => {
-        // An item added between two pages' fetches shifts the later page by
-        // one, which would list an item twice.
-        const byId = new Map<string, T>();
-        for (const item of results.flatMap((r) => r.items)) {
-          if (!byId.has(item.id)) byId.set(item.id, item);
-        }
-        const items = [...byId.values()];
-        setData((l) => ({
-          ...l,
-          items,
-          hasMore: results[results.length - 1].hasMore,
-        }));
-      })
+    refetchPages(list.page, (page) => fetchPage(page))
+      .then(({ items, hasMore }) => setData((l) => ({ ...l, items, hasMore })))
       .catch(() => {});
   }, [setData]);
 

src/hooks/playlist/usePlaylistListSync.ts

@@ -10,6 +10,7 @@ import { useEffect, useLayoutEffect, useRef } from "react";
 import type { Playlist } from "../../../shared/playlist.ts";
 import { useWS, useWSEvent } from "../ws/useWS.ts";
 import { insertAt, usePositionMemory } from "../feed/usePositionMemory.ts";
+import { withByDate } from "../../utils/feed/pagedList.ts";
 
 /** Passed to {@link usePlaylistListSync} by each page, to fit its list. */
 export interface PlaylistListSyncOptions {
@@ -29,12 +30,12 @@ export interface PlaylistListSyncOptions {
 }
 
 /**
- * Applies the socket's playlist events to `items`, the loaded list, which
- * `setPlaylists` updates. A created playlist goes first, an updated one
- * changes in place or leaves when it turns private (unless `isOwner`), one
- * that left comes back where it was when it returns, a deleted one leaves,
- * and a playlist's `dumpCount` follows its dumps. A renamed user's playlists
- * take their new name.
+ * Applies the socket's playlist events to `items`, the loaded list, newest
+ * first, which `setPlaylists` updates. A created playlist goes where its date
+ * puts it, first when new, an updated one changes in place or leaves when it
+ * turns private (unless `isOwner`), one that left comes back where it was
+ * when it returns, a deleted one leaves, and a playlist's `dumpCount` follows
+ * its dumps. A renamed user's playlists take their new name.
  */
 export function usePlaylistListSync(
   items: Playlist[],
@@ -73,7 +74,7 @@ export function usePlaylistListSync(
         if (oldIdx !== undefined) return insertAt(prev, playlist, oldIdx);
         // An update never adds a playlist the list doesn't hold.
         if (ev.type === "updated" || noNewEntries) return prev;
-        return [playlist, ...prev];
+        return withByDate(prev, playlist);
       }
 
       if (ev.type === "deleted") {