fix(tty): drain pending feature-detection replies on exit#391
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Reporter saw `^[]11;rgb:...^[\^[[33;1R^[[?62;1;4c` printed by fish / bash right after exiting reasonix. Those bytes are RESPONSES — OSC 11 bg-color, CPR cursor-position, DA1 device-attributes — sent by the terminal in reply to queries the runtime / a dep emitted during session startup. The dist bundle has none of those query bytes itself, so the source is bun's tty feature-detection path or a transitive dep doing color-scheme detection. Whoever sent them, the responses sat in stdin's queue until reasonix exited. The parent shell then read them and rendered the bytes as input. Add `drainTtyResponses(50ms)` and call it in chat.tsx's exit finally, after `runtime.closeAll()`. Best-effort: sets raw mode, reads-and- discards anything still queued for 50ms, restores cooked. No-op when stdin isn't a TTY or raw mode isn't available. 0.30.3's alt-screen default is the upstream mitigation (DECSET 1049 flushes the input queue on most terminals); this is the program-side mitigation that's independent of which terminal the user is in.
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Closes #365.
Why
Reporter saw
^[]11;rgb:...^[\^[[33;1R^[[?62;1;4cprinted by fish / bash right afterexit. Those bytes are responses, not queries:\x1b]11;rgb:...\x1b\— OSC 11 reply (terminal background color)\x1b[33;1R— CPR reply (cursor position)\x1b[?62;1;4c— DA1 reply (primary device attributes)So something sent the matching queries (
\x1b]11;?\x1b\,\x1b[6n,\x1b[c) into the tty during the session. I scanned the v0.30.2 dist bundle for the raw query bytes — zero hits. The source is the runtime (bun does some tty feature detection on startup) or a transitive dep doing color-scheme detection. Either way, the responses sat in stdin's queue until reasonix exited; the parent shell then read them and rendered the bytes as if the user typed them.What changes
src/cli/ui/drain-tty.ts— newdrainTtyResponses(timeoutMs = 50)helper. Sets raw mode, reads-and-discards anything pending fortimeoutMs, restores cooked. No-op when stdin isn't a TTY or raw mode isn't available.src/cli/commands/chat.tsx—await drainTtyResponses()in the exit finally block, afterruntime.closeAll().Two-layer mitigation:
\x1b[?1049h/\x1b[?1049l, which flushes the input queue on most terminals.The drain runs even with
--no-alt-screen, so legacy in-shell scrollback users get the fix too.Tests
tests/drain-tty.test.ts— 3 cases: returns immediately on non-TTY stdin; respects the timeout cap when raw mode is available; doesn't blow up when a terminal-response burst arrives mid-window.Test plan
npm run verify— 135 files / 2155 passed / 1 skipped (was 2152, +3 new)bunx reasonix@<this PR> code→ exit → no escape junk in fish prompt--no-alt-screenmode → still gets the drain → no junk