Every folder navigation re-downloaded the full listing: `listFolder` cache-busted
with `?t=<ts>` + `Cache-Control: no-store`, so back/forward and re-entering a
folder always paid a full round-trip + payload.
Now the files browser caches listings in memory and serves SWR:
- On navigation it paints a previously-visited folder instantly from cache, then
revalidates with `If-None-Match` (the backend ETag covers folders + files +
favorite/share badges, so it's a faithful validator). Unchanged → 304 with an
empty body; changed → 200 refreshes cache + UI.
- A generation token guards against a slow in-flight response clobbering a newer
navigation; breadcrumbs now resolve independently so they never block the grid
paint.
- Mutations (create/upload/rename/move/copy/delete, incl. the move dialog) go
through `reload()`, which drops the cache and refetches fresh — no stale view
after an action.
API layer (`folders.ts`):
- `fetchFolderListing(id, { etag?, forceRefresh? })` does the conditional fetch
(200 → parsed listing + ETag, 304 → empty); `listFolder` stays as a
non-conditional wrapper for the move-dialog tree.
- A small LRU (cap 40) cache with `getCachedFolder` / `cacheFolder` /
`invalidateFolderCache`. `cache: 'no-store'` keeps the browser HTTP cache out
of the way; revalidation is driven entirely by our own ETag.
Net: instant back/forward navigation, and an unchanged folder revalidates with a
0-byte 304 instead of re-downloading the whole listing. Validated: 7 new unit
tests (conditional If-None-Match + 304, LRU eviction/recency, invalidation),
npm run check, and a headless render of the real files route (list + grid).
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01M8Vb9QHmLZnEMzHz7MrFy6
Claude
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