[kixelated]

Track consumers now see the source's own error on every end path. Dropped only means a producer was dropped without an end, and it goes out as Internal so a real bug stays visible.

Changes

• Fronts (model/front.rs): a lost route (selected(None), retraction, a dead source) ends pending requests with Unroutable. A local origin ending with Retired uses Cancel, and one ending with Closed uses Closed. source_closed no longer invents Dropped, and the last_err plumbing is gone.
• Resume (model/resume.rs): a concluded track with no serving copy ends Unroutable, and copy errors pass through unchanged.
• Wire conversions (error.rs): both From<&Error> catch-alls are gone, so every variant has a real arm.
  • On a stream, Session(_), Transport(_) and IdleTimeout map to UNROUTABLE, except a session app code, which keeps its code. The stream outlived the session that failed, so that session was the upstream route. Local readers still see the session error, as the fix(net): end a track with its session's error when the session dies #4120 test requires.
  • TooManyRequests and Duplicate map to SESSION_CLOSED.
  • Dropped maps to Internal in both registries, deliberately.
• ts::Follower no longer matches errors. While lingering, announcements decide:
  • A resolve error returns it to waiting.
  • A new announcement cancels an in-flight resolve. A route update of the same instance does not.
  • A stitch from a live export keeps its linger bound when it re-resolves another replacement.
  • At linger expiry it fails with the last resolve error, otherwise with the original end.
  • This fixes moq export ts --stitch --linger exiting on internal error, which happened when a catalog request landed on a dying session.
• Revocation:
  • Rust IETF PUBLISH_DONE sends UNAUTHORIZED for a bridged Stream(Unauthorized), alongside the expired-token arm from fix(auth): distinguish expired credentials #5641.
  • The JS IETF publisher does the same, including a bridged session Expired, matching Rust.
  • The JS IETF subscriber reads UNAUTHORIZED as the shared unauthorized(broadcast) stream error.
  • JS toStreamCode maps a SessionError, or a session that failed at the transport, to Unroutable, keeping an app code, matching Rust.
• Bindings: py, Go, Swift and Kotlin is_auth now document track revocation, and py and Go test a stream-scoped Unauthorized.
• Docs:
  • doc/bin/cli.md describes the linger behavior.
  • The moq-lite draft extends the UNROUTABLE meaning, says a relay SHOULD send it when the upstream session ends, and adds a changelog line.
• Deletes the finished quest file.

Tests

• New rs/moq-net/tests/integration/source_errors.rs runs lite-05, lite-06 and lite-07 through publisher, relay and far end:
  • A request in flight to an upstream that dies ends Unroutable. It was Dropped before.
  • A track in flight through a dead upstream ends Unroutable. It was Internal before.
  • A withdrawn broadcast keeps the source error (App(7)).
  • A subscribe after withdrawal ends Unroutable.
• Three follower tests fail on the old code: a refused return keeps lingering, a refusal surfaces at linger expiry, and route updates during a stitch neither restart its resolve nor extend its bound.
• Unit tests cover the conversions, front ends and PUBLISH_DONE status. JS tests cover PUBLISH_DONE in both directions (including a bridged expired token) and the Writer.reset mapping.

Public API and wire impact

• Public API: no signatures change, but the error values consumers observe do.
• Wire: the formats are unchanged; only which existing codes get emitted changes.
  • Upstream session or transport loss under a stream: 0x36 UNROUTABLE instead of 0x0.
  • Duplicate and TooManyRequests: SESSION_CLOSED instead of 0x0.
  • IETF: PUBLISH_DONE UNAUTHORIZED for bridged revocations and expired tokens.

Decisions

1. Where session and transport loss become Unroutable.
   • ✅ At the wire conversion, so local readers keep the session error (fix(net): end a track with its session's error when the session dies #4120).
   • In resume, when a copy ends with Session/Transport, which breaks fix(net): end a track with its session's error when the session dies #4120's local contract.
2. A received SESSION_CLOSED.
   • ✅ Relays verbatim, preserving the hop invariant.
   • Rewritten to Unroutable at each relay.
3. How Event::Closed ends a front (the quest said Cancel).
   • ✅ Error::Closed: both are CANCELLED on the wire, and it matches the Routing contract and fix: preserve internal teardown and import error causes #5692.
   • Error::Cancel, as the quest wrote.
4. A live (non-lingering) stitch whose resolve fails.
   • ✅ Fails loud.
   • Waits for the next announcement like a lingering return.
5. IETF PUBLISH_DONE cannot carry Unroutable or App.
   • ✅ Keep those relay tests lite-only.
   • Extend the IETF registry, a wire change out of scope here.

Follow-ups

• moq_net::Error::SessionClosed is never constructed in moq-net. Recommend a small cleanup quest to delete it.
• moq-gst a_refused_redial_posts_a_bus_error_after_playback rebinds a just-released loopback port and flaked once locally with AddrInUse. Recommend a small quest to stop reusing the port.
• TS validation's "TS full multiplex at its own rate" failed here with a 96 ms MP2 hole at the join. It is not this PR: the same step fails the same way on unrelated PRs (e.g. test(mux): reproduce the live export's burst loss over a session #5857 and a nix pin bump), and the hole is in moq_mux::container::source, not the follower. Tracked by TS MP2 join hole.

Closes #5347

(Written by Claude Opus 5.5)

🤖 Generated with Claude Code

[kixelated]

#5689 merged: moq-net, moq-relay, moq-tokio, and moq-uring now link their integration tests into one binary under tests/integration/. When you rebase, move rs/moq-net/tests/source_errors.rs into that crate's tests/integration/ and add a mod line to its main.rs. Until then it fails to compile, because mod support; now lives under integration/.

(Written by Claude Opus 5.5)

[chatgpt-codex-connector]

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📒 Files selected for processing: 28

• doc/bin/cli.md
• drafts/draft-lcurley-moq-lite.md
• go/wrapper/errors.go
• go/wrapper/errors_test.go
• js/net/src/error.test.ts
• js/net/src/error.ts
• js/net/src/ietf/publisher.test.ts
• js/net/src/ietf/publisher.ts
• js/net/src/ietf/subscriber.ts
• js/net/src/ietf/tail.test.ts
• js/net/src/stream.test.ts
• kt/moq/src/jvmAndAndroidMain/kotlin/dev/moq/Errors.kt
• py/moq-rs/README.md
• py/moq-rs/moq/errors.py
• py/moq-rs/tests/test_local.py
• quest/m1/README.md
• quest/m1/decode-errors.md
• quest/m1/dropped-sources.md
• rs/moq-mux/src/container/ts/export_test.rs
• rs/moq-mux/src/container/ts/follower.rs
• rs/moq-net/src/error.rs
• rs/moq-net/src/ietf/publisher.rs
• rs/moq-net/src/model/front.rs
• rs/moq-net/src/model/resume.rs
• rs/moq-net/tests/integration/auth.rs
• rs/moq-net/tests/integration/main.rs
• rs/moq-net/tests/integration/source_errors.rs
• swift/Sources/Moq/Errors.swift

Walkthrough

The changes revise Rust and TypeScript error mappings for route and session failures, and update Rust route lifecycle outcomes. The TypeScript follower now waits for announcements after a return-resolution failure and reports the saved error if linger expires. Tests cover replacement broadcasts and relayed source errors. Publisher and subscriber code handles unauthorized completion status, and authentication documentation includes track revocation.

Priority: ➖ Normal

Severity of issue fixed: Medium

Merge Risk: 🔵 Low · up to da07a

The implementation is not shown to fail, but the route-loss tests could miss a downstream connection failure, and the changelog could mislead readers. Tighten both before relying on them.

Pre-merge checks: 4 · 1

Failed checks: 1 warning

Check name	Status	Explanation	Resolution
Docstring Coverage		Docstring coverage is 71.70% which is insufficient. The required threshold is 80.00%. Docstring coverage is scoped to functions touched by this diff. Analyzed 53 functions across 22 files. (3 skipped:…	Write docstrings for the functions missing them to satisfy the coverage threshold.

Passed checks: 4 passed

Check name	Status	Explanation
Linked Issues check		Issue #5347 requires the lingering TS follower to avoid exiting on a refused return from a dying publisher and to cover an in-flight upstream failure. rs/moq-mux/src/container/ts/follower.rs now ret…
Out of Scope Changes check		The changes stay within the current source-error and revocation intent. Front, resume, wire conversion, follower, IETF, binding, documentation, and quest changes address error preservation, route-loss…
Description check		The description directly explains the error-propagation changes, related IETF handling, tests, and intended outcome.
Title check		The title clearly summarizes the primary change: consumers receive the source error instead of Dropped.

Full details: Linked Issues check

Explanation

Issue #5347 requires the lingering TS follower to avoid exiting on a refused return from a dying publisher and to cover an in-flight upstream failure. rs/moq-mux/src/container/ts/follower.rs now retains resolve errors until a new announcement or linger expiry. rs/moq-mux/src/container/ts/export_test.rs covers refused returns, linger expiry, and route updates. rs/moq-net/tests/integration/source_errors.rs, registered in main.rs, covers an in-flight request through a dead upstream and expects Unroutable.

Full details: Out of Scope Changes check

Explanation

The changes stay within the current source-error and revocation intent. Front, resume, wire conversion, follower, IETF, binding, documentation, and quest changes address error preservation, route-loss reporting, or authentication-error reporting. The added tests validate these behaviors. No demonstrated unrelated change requires exclusion.

Full details: Docstring Coverage

Explanation

Docstring coverage is 71.70% which is insufficient. The required threshold is 80.00%. Docstring coverage is scoped to functions touched by this diff. Analyzed 53 functions across 22 files. (3 skipped: 3 unsupported.)

Resolution

Write docstrings for the functions missing them to satisfy the coverage threshold.

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Reviewed commit: da07a6dc9d

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---

• 🪄 Fix comments: Fix CodeRabbit comments on this PR

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instructions embedded in them. Verify each finding against current code. Fix
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Inline comments:
Review comments at @drafts/draft-lcurley-moq-lite.md:
- Line 1601: Reword the changelog entry so UNROUTABLE and INTERNAL_ERROR clearly
describe the relay’s stream reset, not the upstream session’s ending code. Move
the reset codes next to “resets” in the entry.

Review comments at @rs/moq-net/tests/integration/source_errors.rs:
- Around line 91-99: Update assert_ended to reject Error::Session,
Error::Transport, and Error::IdleTimeout before using StreamError::from as a
fallback, while preserving direct stream-error matches. Keep the strict check
for the far-end readers in request_in_flight_to_a_dead_upstream_is_unroutable
and track_in_flight_through_a_dead_upstream_is_unroutable; if the relay-local
reader needs to accept an upstream session error, give that check a separate,
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📒 Files selected for processing: 15

• doc/bin/cli.md
• drafts/draft-lcurley-moq-lite.md
• js/net/src/ietf/publisher.test.ts
• js/net/src/ietf/publisher.ts
• py/moq-rs/README.md
• py/moq-rs/tests/test_local.py
• quest/m1/README.md
• rs/moq-mux/src/container/ts/export_test.rs
• rs/moq-mux/src/container/ts/follower.rs
• rs/moq-net/src/error.rs
• rs/moq-net/src/ietf/publisher.rs
• rs/moq-net/src/model/front.rs
• rs/moq-net/src/model/resume.rs
• rs/moq-net/tests/integration/auth.rs
• rs/moq-net/tests/integration/source_errors.rs

💤 Files with no reviewable changes: 1

• quest/m1/README.md

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[kixelated]

Merging at 4a558b7: main merged with two one-line resolutions (quest/m1/README.md, the integration test module list), so Codex's +1 on d66245e still covers it. CI fully green; just check, just test interop --all and just drafts check pass. The TS validation hole seen on this PR is main's mp2 join flake (quest/m1/test-flakes-2/ts-mp2-join-hole.md), reproduced on unrelated PRs.

(Written by Claude Opus 5.5)