jerry/buzz

mirror of https://github.com/block/buzz.git synced 2026-10-27 12:40:30 +00:00

Files

Taylor Ho 218633b8fd fix(link-preview): keep composer fetches user-paced (#7211 )

**Category:** fix
**User Impact:** Link previews can keep loading while a message is being
composed, while sending still has a finite escape hatch and stalled
network transports cannot occupy preview slots forever.

**Problem:** Native metadata and image deadlines could collapse slow
previews into fallback cards while the user was still composing, and a
shared image-host cooldown made pasted batches fail inconsistently after
one rate limit. **Solution:** Keep preview resolution user-paced with no
aggregate request deadline, bound transport inactivity (15s DNS/connect,
30s idle read), serialize image requests by host, and allow at most one
server-directed cooldown wait of up to 30s across an image fetch and its
redirects. The existing bounded post-Send preparation and immediate Skip
paths remain unchanged.

<details>
<summary>File changes</summary>

**desktop/src-tauri/src/commands/link_preview.rs**
Removes aggregate native deadlines so composer metadata work can
complete at the user's pace, while retaining DNS/connect/idle-read
liveness bounds. Adds bounded host-paced image request coordination that
releases its gate during cooldown, waits inline at most once for at most
30 seconds, and cannot renew that wait through redirects or the outer
transient retry. Same-host image and favicon requests remain
deliberately serialized to align with host rate limits.

**desktop/src-tauri/src/commands/link_preview_rate_limit.rs**
Adds a fixed-size striped host gate so concurrent image requests are
serialized without retaining an unbounded attacker-controlled hostname
map.

**desktop/src-tauri/src/commands/link_preview_tests.rs**
Moves native link-preview tests into a dedicated module and covers the
user-paced metadata contract, bounded one-shot cooldown behavior, and
gate release while a rate-limited request sleeps—including a different
host sharing the same bounded gate stripe.

**desktop/src-tauri/src/commands/link_preview_youtube.rs**
Removes the thumbnail fetch deadline so YouTube previews follow the same
composer lifecycle contract while using the shared bounded transport.

**desktop/src/shared/lib/useResolvedLinkPreviews.ts**
Adds development-only metadata outcome diagnostics with elapsed time and
image/fallback state, without logging encoded image payloads.

</details>

### Reproduction steps

1. Open the desktop composer and paste several GitHub pull request links
whose OpenGraph images share a host.
2. Observe that image requests are paced by host instead of racing, and
slow-but-progressing preview work remains pending rather than
immediately becoming a completed favicon fallback.
3. Send while preview work is still pending and confirm **Preparing link
preview** remains bounded by the existing post-Send budget.
4. Use **Skip** during preparation and confirm the message proceeds
immediately.
5. In a development build, inspect the console for `[link-preview]
metadata fetch completed` diagnostics containing elapsed time and image
state without base64 payloads.

### Related issue

N/A — scoped from the linked Buzz implementation room.

### Testing

At current head `dfb394aafbee537e9ffb04ad3732d08f65f30b8e`:

- Production-bound paused-time metadata regression passed through
`fetch_link_preview_metadata`; restoring the former 10-second aggregate
wrapper makes it fail at the pending assertion.
- Native link-preview module: 19/19 passed.
- `cargo check --manifest-path desktop/src-tauri/Cargo.toml` passed.
- Rust formatting and `git diff --check` passed.
- Pre-push `push-head-scope`, org safety, differential file-size,
branch-skew, and `desktop-tauri-checks` hooks passed.

At prior head `59e2dcf167b15c7a3e637ad2608008b7f9cef5f3`:

- Full Tauri Rust suite: 3,056 passed, 19 ignored; integration crates 7
+ 3 passed.
- Focused native link-preview suite: 26/26 passed.
- The pasted multi-preview workflow was exercised in the desktop app and
confirmed improved before draft publication.

---------

Signed-off-by: Taylor Ho <taylorkmho@gmail.com>
Co-authored-by: Carl <acda9e433d19dcd0e6b6840f7f4b98f3a56f1fab98049d444c087019e6d36560@buzz.block.builderlab.xyz>
Co-authored-by: Carl <acda9e433d19dcd0e6b6840f7f4b98f3a56f1fab98049d444c087019e6d36560@users.noreply.github.com>

2026-09-08 12:59:03 -07:00