---
id: review-002-con18b-ws-polish
name: WS small fixes — pre-send cap check, close reasons, custom-route knobs, axum-flavor tests (WS-14/15/17/18/19)
status: completed
depends_on: [review-002-ws13-idle-progress]
scope: moderate
risk: low
impact: component
level: implementation
tags: [websocket, review-002]
---

## Description

Five review-002 minor WS findings that all live in the two WS files
(`byte_adapter.rs`, `upgrade.rs`) — batched because each is small and
they share the review-002-ws13-idle-progress refactor context
(sequence after it; do not parallelize on the same file):

- **WS-14**: the byte-cap check can trip only *after* `poll_write` has
  accepted into the channel (`byte_adapter.rs:326-334, 585-586`) — the
  mux committed the chunk, then the pump 1011s and truncates. Move the
  size check into `poll_write` **before** `try_send` so the mux sees
  the write error instead of the wire.
- **WS-15**: `WriteMsg::CloseWith` hardcodes the reason "text messages
  not supported" for idle-timeout (1001), inbound-size (1011), and text
  (1002) closes (`:316-324`). Carry the reason in the variant; tests
  assert numeric codes today, keep them and add reason asserts where
  cheap.
- **WS-17**: bare-registry WS routes get no knob surface
  (`upgrade.rs:104-111` hardcodes 60 s idle + private 64-session
  semaphore). Add a `WsIdleTimeout`-style request extension mirroring
  `ChannelsPolicy` (or document the fixed values in the module doc —
  implementer's choice, but `upgrade.rs` docs must match reality).
- **WS-18**: write-side stall is unbounded (peer stops reading → write
  pump parks in `ws_sink.send`, 64×16 MiB bounded but time-unbounded).
  Add a write-progress timeout to the write pump (same knob family as
  the read side — share the config surface WS-17 touches).
- **WS-19**: axum-flavor `AxumFraming` arms have no direct unit test
  (cap-trip closes + idle-1001 are asserted on tungstenite only, via
  shared generic code). Mirror one text→1002 and one cap-trip test
  over `AxumFraming`.

## Acceptance Criteria

- [ ] WS-14: over-cap write rejected in `poll_write` pre-`try_send`;
      test asserts the *stream* error, not a wire-level 1011
- [ ] WS-15: close reasons distinct per cause (idle / oversized /
      text); existing close-frame tests updated with reason asserts
- [ ] WS-17: knob surface exists (extension or documented-fixed) and
      `upgrade.rs` module docs match the implementation
- [ ] WS-18: write-progress timeout lands with the same config family;
      test: a peer that stops reading (clog the sink) is evicted
      within the knob (scaled test, tungstenite path)
- [ ] WS-19: two `AxumFraming` unit tests (text→1002, cap-trip) pass
- [ ] `cargo test`, `cargo clippy --all-targets -- -D warnings`,
      `cargo fmt --check` pass

## References

- docs/reviews/002-post-remediation-review.md (Part B', WS-14/15/17/18/19)
- src/websocket/byte_adapter.rs:326-334 (WS-14), :316-324 (WS-15), :584-597 (WS-18), :782-1206 (WS-19 test target)
- src/websocket/upgrade.rs:104-111 (WS-17), :308-317 (the ChannelsPolicy extension pattern to mirror)
- tasks/websocket/review-001-ws-pump-consolidation.md (the generic pump these extend)

## Notes

Slice suggestion (per the review-001 lesson on WS agents): one slice
per finding with its own commit, in the order above (WS-14 is the only
behavior-correctness one; WS-18 is the only new mechanism). If WS-13
(chief-risk task) changed the read-loop shape, rebase-verify the cap
accounting comments before this task's slices — they cite
pre/post-extend order explicitly.

## Summary

WS-14 pre-send cap check in poll_write; WS-15 per-cause close reasons (close_reason module, absorbs the text-message reason bug); WS-18 60s write-progress timeout (close-less teardown on clogged socket); WS-17 WsTimeouts request extension (replaces-state precedence); WS-19 axum-flavor tests. One commit per item.