The pick-a-name B2 migration script (shipped 2026-05-24 in `9abbab6`)
was authored against the @vercel/postgres return shape
`{ rows: [...], rowCount: N }` but uses @neondatabase/serverless's
`neon()` tagged template, which returns the rows array DIRECTLY. As
shipped, the first query at line 37 produced `before === undefined`
and crashed at the `before.length` check on line 44 with
`TypeError: Cannot read properties of undefined (reading 'length')`.
Verified pattern from `lib/database.js` line 33: the wrapper adapter
explicitly checks `Array.isArray(result)` because `neon()` returns
the array directly. AGENTS.md Gotcha #1 mentions @neondatabase and
@vercel/postgres run in parallel; this is exactly the kind of cross-
contamination that creates.
Fix: drop the `{ rows: x }` destructuring in all 3 sites (lines 37,
61, 73) and assign the result directly. Added a 4-line "why" comment
block above the first site so the next person to write a migration
script doesn't make the same mistake.
Hand-verified post-fix:
- node --check: exit 0
- Live run against prod Neon DB: migrated 3 users (admin id=1, alice
id=5, bob id=6) from @tcgvault.com → @deckhearth.com. Idempotent
re-run prints "Nothing to migrate."
- No data loss; the broken first attempt didn't reach the UPDATE
statement (crashed before line 54), so prod was unchanged.
Operator action satisfied by this fix:
- The `pick-a-name` PR #21 / squash `9abbab6` post-merge operator
action ("run the migration script before next admin login") is now
complete in prod. Admin login uses `admin@deckhearth.com`.
Co-authored-by: Cursor <cursoragent@cursor.com>
