fix(devices): keep the device list when AVD enumeration fails

[thelonewander3r]

What Changed

fetchDevices no longer returns a DeviceOperationError when emulator -list-avds exits non-zero. The failure is collected into the same detail channel the hub's own errors already use, and the devices gathered before it are returned.

Why

The hub reports per-backend problems through list.errors while still returning whatever it found, and refresh forwards those into hostStatuses[hostId].detail with the host still ready. The AVD call was the one place that escalated instead:

if (avds.code !== 0) {
  return yield* new DeviceOperationError({ operation: "list", ... });
}

That throws before publish ever runs, so a broken Android toolchain takes down the entire list — the iOS simulators already fetched are discarded, the host is marked failed, and the UI keeps showing stale devices with no indication which platform actually broke. The user-visible result is "Device list failed: The device command failed (exit code 127)" and nothing else.

Degrading keeps the working platforms listing and names Android as the part that failed.

Exit 127 gets its own message: that code comes from ProcessRunner when the spawn never happened, so there is no exit status worth showing and the stderr behind it is an internal error type. Other codes came from the emulator itself, where the first line of stderr is usually the whole explanation.

Tests

Two cases in DeviceService.test.ts: a spawn failure (127) and a real emulator failure (exit 2 with stderr). Both assert the host stays ready and the detail carries the right text. Restoring the error return makes both fail with expected 'failed' to be 'ready'.

The fixture gained one optional parameter to stub the host command result.

Related

Stands alone, but shares a symptom with #11647, which fixes the stale SDK resolution that produced the 127 in the first place. This one limits the blast radius of any such failure; that one removes this cause.

🤖 Generated with Claude Code

Summary by CodeRabbit

• Bug Fixes
  • Device status now remains available when Android emulator discovery fails.
  • Added clearer error details for missing emulator commands, including guidance on installing the Android Emulator or configuring ANDROID_HOME.
  • Device status now reports both backend and emulator-discovery failures together.

[macroscopeapp]

Approvability

Verdict: Approved at 5a311bb

Macroscope's review found this PR approvable — This narrowly scoped device-discovery fix preserves working device results when AVD enumeration fails and surfaces an actionable diagnostic instead of failing the entire host. The behavior is isolated to existing error handling and is covered by focused tests.

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[coderabbitai]

No actionable comments were generated in the recent review. 🎉

ℹ️ Recent review info

⚙️ Run configuration

Configuration used: Path: .coderabbit.yaml

Review profile: CHILL

Plan: Advanced

Run ID: 47782abf-e2ad-4f09-99c3-a41bcf43578b

📥 Commits

Reviewing files that changed from the base of the PR and between 77bca8b and 5a311bb.

📒 Files selected for processing (2)

• apps/server/src/device/DeviceService.test.ts
• apps/server/src/device/DeviceService.ts

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📝 Walkthrough

Walkthrough

DeviceService.fetchDevices now preserves device discovery when emulator -list-avds fails. It adds formatted failure details to existing backend errors. Tests cover exit 127 and exit 2 while confirming the host remains ready.

Changes

AVD failure handling

Layer / File(s)	Summary
AVD failure reporting apps/server/src/device/DeviceService.ts	The service formats AVD command failures, aggregates them with backend errors, and continues to parse successful AVD listings.
AVD failure tests apps/server/src/device/DeviceService.test.ts	The test fixture accepts custom host command results. Tests cover spawn failure and emulator failure while the host remains ready.

Priority: ⬇️ Low

Estimated code review effort: 3 (Moderate) | ~20 minutes

Change: Bug fix

Suggested reviewers: juliusmarminge

Merge Risk: ⚪ Minimal · up to 5a311

AVD enumeration failures now leave other discovered devices available and provide actionable status details. No actionable merge-blocking risk remains.

🚥 Pre-merge checks | ✅ 5

✅ Passed checks (5 passed)

Check name	Status	Explanation
Title check	✅ Passed	The title clearly and concisely describes the main change: preserving the device list when AVD enumeration fails.
Description check	✅ Passed	The description explains what changed, why the change is needed, and how it was tested. The UI Changes section is correctly omitted because the change is not a UI change. The repository checklist is m…
Docstring Coverage	✅ Passed	No functions found in the changed files to evaluate docstring coverage. Skipping docstring coverage check. Docstring coverage is scoped to functions touched by this diff. Analyzed 0 functions across 2…
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.

✨ Finishing Touches

🧪 Generate unit tests (beta)

• Create PR with unit tests

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