Reject dead control targets

[TraderSamwise]

Summary

• require API-resolved managed windows to still be alive before returning control targets
• cover dead focus-window and notification-target resolution paths

Verification

• yarn typecheck
• yarn vitest run src/metadata-server.test.ts
• git diff --check
• yarn lint
• yarn --cwd app typecheck
• yarn --cwd app test
• yarn vitest run
• yarn --cwd app export:web --output-dir /tmp/aimux-epic4-review-fix14-web-export
• yarn build

Summary by CodeRabbit

• Bug Fixes

  • Windows that are no longer active or have been closed are now properly excluded from agent switch controls, expose item lists, and notification target operations for improved reliability.

• Tests

  • Comprehensive test coverage added for window liveness validation across switch controls, expose items, notification targets, and focus workflows to ensure inactive windows are properly filtered.

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Project	Deployment	Actions	Updated (UTC)
app	Ready	Preview, Comment	Jun 20, 2026 6:06am

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ℹ️ Review info

⚙️ Run configuration

Configuration used: defaults

Review profile: CHILL

Plan: Pro

Run ID: 1664e5b4-0c12-48bd-8a32-405f0820ea5f

📥 Commits

Reviewing files that changed from the base of the PR and between 2a602de and a2613e5.

📒 Files selected for processing (6)

• scripts/tmux-control.sh
• src/fast-control.test.ts
• src/fast-control.ts
• src/metadata-server.test.ts
• src/metadata-server.ts
• src/tmux/control-script.test.ts

📝 Walkthrough

Walkthrough

Adds tmux.isWindowAlive liveness filtering to listSwitchableAgentItems and findProjectManagedWindow, and updates openNotificationTarget resume paths to use the liveness-aware findProjectManagedWindow. Existing mocks across three test files are updated to include isWindowAlive, and new tests verify that dead windows are excluded from switch-control lists, expose items, and notification-target/focus-window HTTP handlers.

Changes

Window liveness filtering for managed windows

Layer / File(s)	Summary
Core liveness filtering implementation src/fast-control.ts, src/metadata-server.ts	listSwitchableAgentItems filters listManagedWindows results via tmux.isWindowAlive. findProjectManagedWindow's predicate adds the same liveness check. openNotificationTarget resume paths switch from tmux.findManagedWindow to the liveness-aware findProjectManagedWindow with a sessionId filter.
fast-control and expose-model test updates src/fast-control.test.ts, src/tmux/expose-model.test.ts	All existing TmuxRuntimeManager mocks gain isWindowAlive: vi.fn(() => true). New test in fast-control.test.ts asserts dead windows are excluded from switch-control lists and that resolveAttentionAgent returns null for a dead candidate. New test in expose-model.test.ts asserts dead windows are excluded from listExposeAgentItems.
metadata-server test updates src/metadata-server.test.ts	Existing notification-target and focus-mutation tests now stub and restore TmuxRuntimeManager.prototype.isWindowAlive. New HTTP tests cover: dead resumed-service window → 404, dead resumed-agent window → 404, dead notification-target window → 404 "window not found", dead managed focus-window target → 404 for both focus: false and focus: true.

Estimated code review effort

🎯 3 (Moderate) | ⏱️ ~20 minutes

Possibly related PRs

• TraderSamwise/aimux#122: Extends listSwitchableAgentItems and listExposeAgentItems — the same functions this PR modifies to add liveness filtering.
• TraderSamwise/aimux#134: The Exposé scope ladder uses listSwitchableAgentItems for worktree/project rungs, so its tile set is directly affected by the liveness filter added here.
• TraderSamwise/aimux#187: Modifies the same findProjectManagedWindow helper and openNotificationTarget resume/focus flow in src/metadata-server.ts.

Poem

🐇 Hop, hop — dead panes must go,
No ghost windows in our show!
isWindowAlive now stands the gate,
Only living tmux panes navigate.
The rabbit checks before you switch,
Dead windows vanish without a glitch! 🪟✨

🚥 Pre-merge checks | ✅ 4 | ❌ 1

❌ Failed checks (1 warning)

Check name	Status	Explanation	Resolution
Docstring Coverage	⚠️ Warning	Docstring coverage is 0.00% which is insufficient. The required threshold is 80.00%.	Write docstrings for the functions missing them to satisfy the coverage threshold.

✅ Passed checks (4 passed)

Check name	Status	Explanation
Description Check	✅ Passed	Check skipped - CodeRabbit’s high-level summary is enabled.
Title check	✅ Passed	The title 'Reject dead control targets' directly and clearly summarizes the main change: filtering out dead/invalid control targets across the codebase.
Linked Issues check	✅ Passed	Check skipped because no linked issues were found for this pull request.
Out of Scope Changes check	✅ Passed	Check skipped because no linked issues were found for this pull request.

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✨ Finishing Touches

🧪 Generate unit tests (beta)

• Create PR with unit tests
• Commit unit tests in branch fix/dead-control-targets

---

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[coderabbitai]

Actionable comments posted: 1

🤖 Prompt for all review comments with AI agents

Verify each finding against current code. Fix only still-valid issues, skip the
rest with a brief reason, keep changes minimal, and validate.

Inline comments:
In `@src/metadata-server.test.ts`:
- Around line 889-890: The issue is that await server.start() is called after
mutating TmuxRuntimeManager.prototype but before entering the try/finally block
that manages these prototype stubs, causing stubs to leak into later tests if
start throws an error. Move the await server.start() calls (at lines 889, 960,
and 1020) inside the try block that contains the corresponding
TmuxRuntimeManager.prototype mutations so that the finally block can properly
clean up the stubs regardless of whether start succeeds or fails.

🪄 Autofix (Beta)

Fix all unresolved CodeRabbit comments on this PR:

• Push a commit to this branch (recommended)
• Create a new PR with the fixes

---

ℹ️ Review info

⚙️ Run configuration

Configuration used: defaults

Review profile: CHILL

Plan: Pro

Run ID: d51d6719-7e97-4d03-8c4e-73a9438ba77e

📥 Commits

Reviewing files that changed from the base of the PR and between ece1b05 and 2a602de.

📒 Files selected for processing (5)

• src/fast-control.test.ts
• src/fast-control.ts
• src/metadata-server.test.ts
• src/metadata-server.ts
• src/tmux/expose-model.test.ts

[TraderSamwise]

Review loop resolutions:

• Fixed CodeRabbit summary finding in a2613e5: server.start() for the affected metadata-server prototype-stub tests now runs inside the matching try/finally cleanup block.
• Fixed sub-agent finding in d8bddec/a2613e5: fast-control and tmux-control now keep the current dead pane only for context/index calculation, while excluding dead panes from target selection.

Verification after fixes: yarn typecheck, yarn lint, yarn vitest, yarn build; PR checks are green.