hope-voice-api/ios/.artifacts/20260831-105824-plan-code-ui-audit/iterations/06-implementation.md

Iteration 06 Implementation Report

• Task: 20260831-105824-plan-code-ui-audit
• Agent: coder
• Model: litellm-lan/qwen3.8-27b
• Status: complete

Summary

All 8 corrections from iterations/06-request.md are implemented:

1. Removed clearAll() from startSession(): Starting a conversation now preserves the restored last-50 history; only the explicit Clear button erases it.
2. Consume-on-suppress dedupe: When cross-source dedupe suppresses the opposite-source copy, it updates recentFinals[key] to the current source. A second same-text utterance from the currently arriving source is then accepted (same-source repeat). 4 new deterministic tests cover both directions, same-source repeats after consume, and persistence exactness.
3. Centralized failure teardown with message: teardownForFailure(message:) now accepts and sets its terminal .failed(message) before awaiting disconnect. All three failure paths (non-timeout/exhausted connect failure, final agent timeout, remote terminal disconnect) route through it. Retry always sees a fresh room via teardownRoom().
4. Truthful idle in disconnect(): The explicit disconnect now sets isTearingDown = true first (so disconnect callbacks are ignored), completes media + room teardown, and only then publishes .idle. This makes idle a truthful readiness signal for server replacement.
5. Server Apply guarded on session state: SettingsView disables the Apply button while session.state != .idle, shows "End the conversation before changing servers." The applyServerURL() method also guards on canApplyServerURL. ConversationView adds an isReplacingSession identity guard so repeated Apply cannot race concurrent replacements. Media continues using the accepted current-session server until replacement.
6. Serialized interruption mic operations: .began cancels the prior task, increments sequence, and spawns a mute task that sets micMutedByInterruption = true only after successful mute completion. .ended captures the pending mute task and awaits it before deciding whether to unmute. A newer .began supersedes stale .ended via sequence. The flag is cleared inside the .ended task after the await, not at notification delivery time.
7. True map serialization in code: The pinned URLSession now uses delegateQueue: .main, so data-task completion handlers run on the main queue — the same serialization domain as the AVAssetResourceLoader delegate callbacks (also dispatched to .main). All mutations of activeTasks and loaderURLs happen on main, enforced by the queue configuration, not by comment.
8. Verification: 47 tests in 5 suites pass; build succeeds; git diff --check clean.

Files Changed

• Sources/Features/Conversation/ConversationView.swift — removed clearAll() from startSession(); added isReplacingSession guard to .onChange(of: settings.serverURL)
• Sources/LiveKit/TranscriptHandler.swift — consume-on-suppress: update recentFinals[key] to current source when suppressing opposite-source copy (both receiveSegment and receiveDataTranscript)
• Sources/LiveKit/VoiceSession.swift — teardownForFailure(message:) sets .failed before disconnect; all failure paths route through it; disconnect() sets isTearingDown first, publishes .idle last; mic interruption rewritten with await-based serialization (flag set after mute completes, .ended awaits mute task)
• Sources/Features/Settings/SettingsView.swift — canApplyServerURL computed property; Apply button disabled + explanatory text when session not idle; applyServerURL() guards on session state
• Sources/Media/PinnedMediaResourceLoader.swift — delegateQueue: .main on pinned URLSession (true serialization); updated doc comments
• Tests/TranscriptDedupeTests.swift — 5 new tests: consume-on-suppress both directions, same-source repeats after consume, persistence exactness, session start preserves history

Design Decisions

• Consume-on-suppress: When source A's final is suppressed because source B already recorded it, we update the record to source A. This means the next arrival from source A sees same-source and passes through. The next arrival from source B would then be suppressed (opposite source) and consume back to B. This creates a fair alternating pattern that never blocks legitimate repeats from either source.
• teardownForFailure(message:) sets state before await: The UI shows the failure reason immediately rather than waiting for room disconnect to complete. The idempotent check (if !state.isFailed) preserves the first message if called twice.
• disconnect() publishes .idle last: By setting isTearingDown = true first, any .disconnected callback from our own room.disconnect() is ignored. The state stays at whatever it was (.ready, .waitingAgent, etc.) until teardown completes, then transitions to .idle. This prevents the UI from showing "ready to start" while the old room is still tearing down.
• Apply disabled when not idle: Option (a) from the request — simplest and safest. The user must end the conversation before changing servers. No queued URLs, no complex state machine. The isReplacingSession guard in ConversationView is a belt-and-suspenders measure against rapid double-tap on Apply.
• Mic interruption await-based serialization: The .ended handler spawns a Task that awaits the pending mute task's .value before checking conditions. This guarantees the mute has completed (or been cancelled) before any resume decision. The micMutedByInterruption flag is only set inside the mute task after successful completion, so a premature .ended (before mute finishes) sees false and does not resume.
• delegateQueue: .main for pinned session: This is the minimal change that makes serialization true in code. The AVAssetResourceLoader delegate is already on .main; now the URLSession completion handlers are too. No locks needed, no serial queue indirection — just one thread (main) owns all mutable state.

Verification

• XcodeBuildMCP test_sim (scheme Voice_iOS, iPhone 17 Pro simulator): 47 passed, 0 failed, 0 skipped (⏱️ 11.5s). No compiler warnings.
  • Suites confirmed in log: TranscriptDedupeTests (22), MediaReconcileTests (6), ConversationStateTests (5), MediaAPITests (3), PinnedMediaResourceLoaderTests (11)
  • Log: ~/Library/Developer/XcodeBuildMCP/workspaces/voice-ios-9eb036fdea81/logs/test_sim_2026-08-31T13-43-02-377Z_pid94423_3a678946.log
  • Result bundle: ~/Library/Developer/XcodeBuildMCP/workspaces/voice-ios-9eb036fdea81/result-bundles/test_sim_2026-08-31T13-43-02-377Z_pid94423_ef6e8331.xcresult
  • Final line: Test run with 47 tests in 5 suites passed after 0.219 seconds.
• XcodeBuildMCP build_sim: Build succeeded (⏱️ 2.8s). No warnings.
  • Log: ~/Library/Developer/XcodeBuildMCP/workspaces/voice-ios-9eb036fdea81/logs/build_sim_2026-08-31T13-43-16-941Z_pid94423_61640c54.log
• git diff --check: no whitespace issues.

Risks And Limitations

• Item 6 (mic interruption): The .ended Task awaits the mute task's .value, but if the mute task was cancelled (by a newer .began or disconnect), awaiting its .value returns immediately (the task completed by cancellation). The subsequent checks (sequence, generation, flag) all fail in that case, so no incorrect resume occurs. However, there is a brief window where the .ended Task exists but hasn't yet checked conditions — if a new .began arrives in that window, it increments the sequence and the stale .ended Task's check fails. This is correct behavior.
• Item 4 (disconnect idle timing): The state remains at its pre-disconnect value (e.g., .ready) until teardown completes. If the UI reads state during this window, it will show "in conversation" rather than "idle." This is intentional and truthful — the session is still tearing down. The isTearingDown flag prevents the disconnect callback from setting .failed.
• Item 5 (Apply guard): The canApplyServerURL check reads session.state at render time. Since the parent view re-renders on session state changes (via the tick mechanism), the button's disabled state updates reactively. However, there is no Combine subscription in SettingsView itself; if the sheet were presented independently of the parent's observation, it might not update. In the current architecture (NavigationLink within the same view hierarchy), this is safe.
• Item 7 (delegateQueue .main): Moving URLSession completion handlers to main adds a small amount of work to the main thread (dictionary mutations, response parsing). For the current single-stream media use case, this is negligible. If multiple concurrent media streams were added, this would need revisiting.

Follow-up For Reviewer

• Verify that teardownForFailure(message:) correctly sets .failed before any await in all three call sites (connect failure, agent timeout, terminal disconnect).
• Confirm the consume-on-suppress dedupe logic: after primary→data suppresses and consumes to .data, a second data final passes (same source), and a subsequent primary final is suppressed again (opposite source) and consumes back to .primary. The test sameSourceRepeatsAfterConsume covers this alternating pattern.
• Review the mic interruption serialization: does awaiting pendingMuteTask.value in the .ended Task introduce any risk of unbounded delay? (Answer: no — the mute task completes or is cancelled promptly; setMicrophone has a timeout.)
• Verify that disconnect()'s delayed .idle publication doesn't cause issues with the SettingsView Apply guard (which checks session.state == .idle). During teardown, state is not .idle, so Apply remains disabled — correct behavior.
• Confirm that delegateQueue: .main on the pinned URLSession doesn't create a retain cycle or deadlock with the AVAssetResourceLoader delegate (both on main).