test(hermes): give quit-time Hermes loads their own complete process census

[teamleaderleo]

Summary

HermesFirstClassSupportTests has been failing in "app-host unit tests (changed suites)" on unrelated PRs (#14783 twice, #14788):

• quitTimeSaveRevalidatesCachedHermesProcess at HermesFirstClassSupportTests.swift:939
• freshSynchronousLifecycleLoadDiscoversNewHermesSession at :1022

Both failures print RestorableAgentSessionIndex(entriesByPanel: [:], ..., isComplete: false, ...), which is exactly RestorableAgentSessionIndex.unavailable: ProcessDetectedResumeIndexes.loadOnWorker returns it when the process census is unavailable or incomplete.

Root cause: loadOnWorker read the whole host's process table through the app's shared ProcessSnapshotService. That census fails closed by design (DarwinProcessEnumerator and CmuxTopProcessSampler.enrich count any PID that exits or is reused between listing and reading as missing, and enumerationIsComplete goes false). On a busy CI mini with neighbouring compile jobs spawning and reaping processes, that is routine, so the Hermes assertions were really measuring host process churn.

Change

• ProcessDetectedResumeIndexes.loadOnWorker / loadFreshOnWorker take an optional processSnapshotService (nil keeps today's shared app census; no production call site changes).
• The two Hermes tests inject a complete, empty census (a private CmuxTopProcessReading that enumerates nothing). The fixture PIDs are never live, so the tests still exercise the real revalidation / fresh-discovery logic, without reading the host process table.

Other suites seen red today (different causes, not in this PR)

• WorkspaceForkConversationContextMenuTests (Prevent deep process-tree stack overflow #14785, also main run 36197594615): the four sharedForkProbe* executable-watch tests. The loader is injected there; the likely gate is the file-descriptor headroom check in SharedLiveAgentIndex+ScheduledHibernation.swift (soft RLIMIT_NOFILE minus open fds minus a 128 reserve), which depends on how many fds earlier suites left open in the shared test host.
• DeadKeyCompositionRegressionTests.testOptionDeadKeyUsesGhosttyTranslationInsteadOfStartingComposition (Keep unrelated file descriptors out of notification hooks #14789): Option-as-Alt side claim; config / keyboard state, unrelated to the process census.
• CloudTunnelLaunchGateTests: not in the failing logs inspected here.

Test plan

• CI app-host changed suites: HermesFirstClassSupportTests green

🤖 Generated with Claude Code

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Summary by cubic

Fixes two flaky HermesFirstClassSupportTests that read the whole host process table through the app's shared census, which fails closed whenever any process on the machine exits mid-scan — routine on busy CI runners.

• Adds an optional processSnapshotService to loadOnWorker/loadFreshOnWorker; nil keeps the app's shared census and no production call sites change.
• The two Hermes lifecycle tests now inject a complete, empty census so they exercise real revalidation / fresh-discovery logic without depending on live host processes.

^{Written for commit fdea334. Summary will update on new commits.}

Summary by CodeRabbit

• Tests
  • Updated process-index loading tests to use controlled snapshot data when checking cached and fresh results.
• Internal Improvements
  • Process-index loading now supports a supplied snapshot provider while retaining the existing default behavior when none is provided. No user-facing changes are noted.

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ℹ️ Recent review info

⚙️ Run configuration

Configuration used: Repository: manaflow-ai/cmux/.coderabbit.yaml

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📥 Commits

Reviewing files that changed from the base of the PR and between c07c13a and fdea334.

📒 Files selected for processing (2)

• Sources/ProcessDetectedResumeIndexes.swift
• cmuxTests/HermesFirstClassSupportTests.swift

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📝 Walkthrough

Walkthrough

Process-index loaders now accept an optional process snapshot service and pass it to cached or fresh snapshot capture. Tests use a fixture-backed service with an empty process census.

Changes

Process Snapshot Injection

Layer / File(s)	Summary
Pass the service through index loading Sources/ProcessDetectedResumeIndexes.swift	The worker loaders accept an optional snapshot service. Loading uses cached capture when a maximum snapshot age is set, and fresh capture otherwise.
Test loading with a fixture service cmuxTests/HermesFirstClassSupportTests.swift	Process-index tests pass a fixture-backed service. Its reader reports a complete, empty process listing and no process details.

Priority: ⬇️ Low

Estimated code review effort: 2 (Simple) | ~10 minutes

Change: Bug fix

Suggested reviewers: austinywang

Merge Risk: ⚪ Minimal · up to fdea3

The fixture-backed tests can use an empty process census without changing the app’s default census behavior. No actionable merge-blocking risk remains.

🚥 Pre-merge checks | ✅ 23 | ❌ 2

❌ Failed checks (2 warnings)

Check name	Status	Explanation	Resolution
Description check	⚠️ Warning	The description provides a strong problem statement and implementation summary, but it does not include the required Testing section with executed commands and results. The checklist is also missing, …	Add a Testing section that names the test command or CI lane, states what passed, and identifies anything not verified. Add the required Checklist section and mark each applicable item. Include a Demo Video section only if this change is co…
Docstring Coverage	⚠️ Warning	Docstring coverage is 14.29% which is insufficient. The required threshold is 80.00%. Docstring coverage is scoped to functions touched by this diff. Analyzed 14 functions across 2 files.	Write docstrings for the functions missing them to satisfy the coverage threshold.

✅ Passed checks (23 passed)

Check name	Status	Explanation
Title check	✅ Passed	The title clearly identifies the Hermes test change and the use of a complete process census. It does not mention the fresh-load test or optional API change, but it remains specific and related to the…
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.
Cmux Cloud Persistent Session And Early Input	✅ Passed	PASS: The pull request changes only process snapshot loading and Hermes tests. It does not change Cloud terminal creation, cmux-tui transport, manual renderer admission, input routing, authentication,…
Cmux Swift Actor Isolation	✅ Passed	PASS: The production diff only injects ProcessSnapshotService into existing worker methods and forwards it to snapshot capture. ProcessSnapshotService is an actor, and the captured types and worke…
Cmux Swift Blocking Runtime	✅ Passed	The production diff only adds an optional ProcessSnapshotService parameter and forwards it to existing snapshot capture APIs. The added lines introduce no semaphore, blocking wait, sleep, delayed disp…
Cmux Browser Automation Off-Main	✅ Passed	PASS. The PR changes only Sources/ProcessDetectedResumeIndexes.swift and cmuxTests/HermesFirstClassSupportTests.swift. It adds no browser.* socket commands and does not modify `TerminalControlle…
Cmux Expensive Synchronous Load	✅ Passed	The production diff only injects an optional process snapshot service into the existing worker loader. It does not add or move an expensive agent-history load. RestorableAgentSessionIndex.load(...) …
Cmux Cache Substitution Correctness	✅ Passed	The diff does not replace a fresh authoritative read with a cache. It adds an optional ProcessSnapshotService injection to ProcessDetectedResumeIndexes; nil preserves the existing app service an…
Cmux No Hacky Sleeps	✅ Passed	PASS. The PR changes only Swift files. The configured check covers TypeScript, JavaScript, shell, and non-Swift build/runtime scripts. The diff adds no fixed sleeps, timers, polling, or wall-clock wai…
Cmux Algorithmic Complexity	✅ Passed	The production diff only adds an optional ProcessSnapshotService parameter and forwards it to existing snapshot capture calls. It introduces no loops, scans, sorting, filtering, joins, or per-target…
Cmux Swift Concurrency	✅ Passed	The diff adds an optional process snapshot service and forwards it through existing async/await capture calls. It adds no Dispatch queues or groups, Combine state, completion-handler API, or fire-and-…
Cmux Swift @Concurrent	✅ Passed	The changed worker path keeps ProcessDetectedResumeIndexes.loadOnWorker annotated with @concurrent (with @Sendable for older compilers). The added processSnapshotService parameter only injects…
Cmux Swift Package Boundaries	✅ Passed	PASS. The production diff only adds an optional ProcessSnapshotService injection point and forwards it to existing snapshot capture paths. It does not introduce or materially expand independent doma…
Cmux Swiftpm Lockfiles	✅ Passed	The PR changes only Sources/ProcessDetectedResumeIndexes.swift and cmuxTests/HermesFirstClassSupportTests.swift. It does not change a Package.swift, Package.resolved, .gitignore, workflow, o…
Cmux Swift Logging	✅ Passed	The production diff only adds an optional process snapshot service and passes it to snapshot capture. It adds no print, debugPrint, dump, NSLog, Logger, file logging, or diagnostic output. T…
Cmux User-Facing Error Privacy	✅ Passed	PASS. The production diff only adds an optional process snapshot service and forwards it to existing capture calls. It adds no user-facing errors, alerts, command output, API bodies, or recovery copy.…
Cmux Full Internationalization	✅ Passed	The diff changes process-snapshot injection in production code and adds a test-only process census fixture. It adds no user-facing Swift text, localization keys, catalogs, web messages, or locale data…
Cmux Swiftui State Layout	✅ Passed	PASS. The PR changes process-snapshot loading and Hermes test fixtures only. The changed files contain no SwiftUI views or new ObservableObject, @Published, GeometryReader, lazy/list row store referen…
Cmux Architecture Rethink	✅ Passed	The diff does not introduce any prohibited timing, blocking, polling, lock, observer, side-channel, duplicate wiring, or UI lifecycle ownership pattern. It adds an optional process snapshot dependency…
Cmux Swift Auxiliary Window Close Shortcuts	✅ Passed	The pull request changes only process snapshot loading and Hermes test fixtures. The authoritative diff contains no NSWindow, NSPanel, NSWindowController, SwiftUI Window, or WindowGroup changes, and i…
Cmux Source Artifacts	✅ Passed	The PR changes only two existing Swift source files: Sources/ProcessDetectedResumeIndexes.swift and cmuxTests/HermesFirstClassSupportTests.swift. The additions are production source changes and a …
Cmux No Test Or Debug Seam In Production Source	✅ Passed	PASS. The production diff in Sources/ProcessDetectedResumeIndexes.swift adds optional process-service dependency injection to existing worker methods. It adds no #if DEBUG or test-build guard, no …

Full details: Description check

Explanation

The description provides a strong problem statement and implementation summary, but it does not include the required Testing section with executed commands and results. The checklist is also missing, and the test plan remains unchecked.

Resolution

Add a Testing section that names the test command or CI lane, states what passed, and identifies anything not verified. Add the required Checklist section and mark each applicable item. Include a Demo Video section only if this change is considered user-facing behavior.

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[github-actions]

Merge receipt for fdea334a92: every check was green at merge (16 verified; 14 skipped by policy). Full suite runs on main after merge.