yellowjacket/.planning/phases/02-backend-correctness/02-VERIFICATION.md

phase, verified, status, score

phase	verified	status	score
02-backend-correctness	2026-03-03T00:30:00Z	passed	5/5 must-haves verified

Phase 2: Backend Correctness Verification Report

Phase Goal: All known error handling gaps are closed, configuration is secure, and the backend reports problems honestly instead of swallowing them Verified: 2026-03-03T00:30:00Z Status: passed Re-verification: No — initial verification

Goal Achievement

Observable Truths

#	Truth	Status	Evidence
1	The package-level startupErr variable no longer exists; startup errors are stored in a YellowJacketApp struct field	✓ VERIFIED	grep "^var startupErr" backend/app.go returns nothing; startupErr error at line 42 is a struct field; yj.startupErr used at lines 153, 154, 263, 264
2	Config files are written with 0o644 permissions	✓ VERIFIED	os.WriteFile(c.filePath, confFileData, 0o644) at line 152 of config.go; no 0o666 anywhere in the file
3	MPRIS lifecycle callback errors (Pause, Seek) appear in the application log instead of being silently discarded	✓ VERIFIED	4 yj.logger.Warn("MPRIS ... failed" calls at lines 184, 190, 198, 205 in app.go; no _ = yj.player anywhere in app.go
4	Artist credit link creation checks the actual error — only UNIQUE constraint violations are ignored, all other errors are surfaced	✓ VERIFIED	database.IsUniqueViolation(err) check at line 1127 of library.go; non-unique errors logged and sent to metrics.addWarning at lines 1128-1141; no _, _ = q.CreateArtistCreditArtist remains
5	Library.Scan() returns warnings in ScanMetrics and fatal errors in the error return	✓ VERIFIED	scanErr at line 225 only set from commitBatch fatal tx commit errors (line 391); 11 metrics.addWarning calls for walk/extraction/commit/orphan/variant paths; handleConfigUpdate at line 1365 captures scanMetrics and logs scanMetrics.Warnings count

Score: 5/5 truths verified

Required Artifacts

Artifact	Expected	Status	Details
backend/app.go	Startup error as struct field + MPRIS error logging	✓ VERIFIED	startupErr error struct field line 42; 4 MPRIS Warn log calls
backend/config/config.go	Secure config file permissions	✓ VERIFIED	0o644 at line 152
backend/database/errors.go	IsUniqueViolation helper	✓ VERIFIED	20 lines, exports IsUniqueViolation, uses sqlite3.SQLITE_CONSTRAINT_UNIQUE
backend/database/database.go	Migration 3: UNIQUE index on artist_credit_artist	✓ VERIFIED	version < 3 block at line 224; deduplicates then creates idx_artist_credit_artist_unique
backend/library/metrics.go	ScanWarning struct and addWarning method	✓ VERIFIED	ScanWarning struct (lines 58-62) with FilePath/Phase/Err; Warnings []ScanWarning field (line 54); mutex-protected addWarning method (lines 94-103)
backend/library/library.go	Reclassified error paths + updated cachedLinkArtist	✓ VERIFIED	11 metrics.addWarning calls; database.IsUniqueViolation at line 1127; handleConfigUpdate captures scan metrics

Key Link Verification

From	To	Via	Status	Details
app.go:OnStartup	app.go:OnDomReady	yj.startupErr field	✓ WIRED	Set at line 153, checked at line 263 — no package-level var involved
app.go:MPRIS callbacks	yj.logger	Warn log on Pause/Seek/Stop error	✓ WIRED	4 calls at lines 184, 190, 198, 205
library.go:cachedLinkArtist	database/errors.go:IsUniqueViolation	Error check on CreateArtistCreditArtist	✓ WIRED	database.IsUniqueViolation(err) at line 1127; import at line 22
library.go:Scan	metrics.go:addWarning	Non-fatal errors reclassified	✓ WIRED	11 calls across walk, extraction, commit, orphan, variant, FTS paths
database.go:runMigrations	artist_credit_artist table	Migration 3 UNIQUE index	✓ WIRED	idx_artist_credit_artist_unique at line 245; dedup + PRAGMA user_version = 3

Requirements Coverage

Requirement	Source Plan	Description	Status	Evidence
CORR-05	02-01	Package-level startupErr moved to struct field	✓ SATISFIED	No var startupErr in app.go; startupErr error as struct field; all references use yj.startupErr
CORR-06	02-01	Config file written with 0o644 permissions	✓ SATISFIED	0o644 at config.go:152; no 0o666 anywhere
CORR-07	02-01	MPRIS callback errors logged instead of swallowed	✓ SATISFIED	4 Warn-level log calls for Pause, PlayPause(pause), Stop, Seek; no discarded _ = yj.player
CORR-08	02-02	Artist credit link error properly checked	✓ SATISFIED	database.IsUniqueViolation check; non-unique errors become warnings; migration 3 adds UNIQUE index
CORR-09	02-02	Scan() separates warnings from fatal errors	✓ SATISFIED	scanErr only for fatal tx commits; 11 addWarning calls; handleConfigUpdate logs warning count

Orphaned requirements: None. All 5 requirement IDs (CORR-05 through CORR-09) from REQUIREMENTS.md Phase 2 are covered by plans 02-01 and 02-02.

Anti-Patterns Found

File	Line	Pattern	Severity	Impact
—	—	None found	—	—

No TODOs, FIXMEs, placeholders, or empty implementations found in any modified files. go vet ./backend/... passes. go build ./backend/... compiles cleanly.

Human Verification Required

1. MPRIS Error Logging Under Real Conditions

Test: Trigger MPRIS Pause/Stop/Seek while the player is in a state that causes failure (e.g., no audio loaded) Expected: Warn-level log lines appear with "MPRIS Pause failed" / "MPRIS Stop failed" / "MPRIS Seek failed" Why human: Requires a running Linux desktop with MPRIS-capable media key events and specific player error states

2. Config File Permissions on Disk

Test: After app writes config, run stat -c '%a' ~/.config/yellowjacket/config.toml Expected: Shows 644 Why human: Requires running the actual app to trigger config write; umask may interact

3. Scan Warning Accumulation End-to-End

Test: Scan a library with some corrupted/unreadable audio files Expected: Scan() returns non-nil ScanMetrics.Warnings with entries for failed files, while the overall error return is nil (scan completed) Why human: Requires crafted test files with specific corruption patterns

Gaps Summary

No gaps found. All 5 success criteria from the ROADMAP are verified:

1. ✓ Package-level startupErr eliminated, struct field in place
2. ✓ Config written with 0o644
3. ✓ All 4 MPRIS callbacks log errors at Warn level
4. ✓ cachedLinkArtist checks errors via IsUniqueViolation, surfaces non-unique failures
5. ✓ Scan() error return is fatal-only; warnings accumulated in ScanMetrics.Warnings; handleConfigUpdate logs warning count

All commits verified: 2a86408, 0860b2f, e6866de exist in git history.

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Verified: 2026-03-03T00:30:00Z Verifier: Claude (gsd-verifier)