Summary

Adds the five test cases requested in #10 (stopword filtering, multi-keyword ranking, tie-break ordering, explicit-id order preservation, archived-session exclusion) plus one small implementation fix that the fetchSessionsById preserves input order test surfaced.

Closes #10.

Tests

All five tests use the shared src/server/services/ai/__test_db.ts helper, not a private sqlite instance (acceptance criterion 3).

1. Stopword filtering - "is the api session healthy?" ends up scoring against api and healthy; is, the, and session are in STOPWORDS at resolver.ts:36-72. A session named api-gateway matches via api; a session named unrelated-name matches nothing.

2. Multi-keyword match - "the sourcebridge oauth session" ranks a cwd /repos/sourcebridge/oauth-provider above /repos/sourcebridge/ui because scoreSession adds +2 per token-in-haystack hit (both tokens in the first, only one in the second).

3. Stable ordering on ties - two sessions that score identically on target sort by lastActivityAt descending. Uses explicit timestamps (2020 vs 2030) to avoid racing on the default datetime('now') tick.

4. fetchSessionsById preserves input order - passing ["b", "a"] returns ["b", "a"], not the SQLite IN-clause default. See implementation fix below.

5. Archived sessions excluded - a session with status: "archived" (and isWorking: false) does not leak into the resolver pool. Inserts via db.insert(...) directly so the test exercises the resolver's WHERE clause without being restricted by the insertSession helper's narrower type union.

Test count before: 4. After: 9. bun test src/server/services/ask/resolver.test.ts runs all 9 green.

Implementation fix

fetchSessionsById at src/server/services/ask/resolver.ts:170 previously mapped the raw SQLite result:

const rows = await db.select().from(sessions).where(inArray(sessions.sessionId, ids));
return rows.map((row) => ({ ... }));

SQLite's IN clause doesn't preserve input order, so callers got back results in insertion / rowid order. The fix indexes the rows by sessionId and walks ids in the order the caller passed them:

const byId = new Map(rows.map((row) => [row.sessionId, row]));
return ids
  .map((id) => byId.get(id))
  .filter((row): row is (typeof rows)[number] => Boolean(row))
  .map((row) => ({ ... }));

This keeps "@mention"-style references in the UI stable regardless of how the sessions were inserted.

Testing

bun test src/server/services/ask/resolver.test.ts
#  9 pass
#  0 fail
#  15 expect() calls

bunx biome check src/server/services/ask/resolver.ts src/server/services/ask/resolver.test.ts
# Checked 2 files in 2ms. No fixes applied.

bunx tsc --noEmit
# (exit 0)

AI disclosure

This contribution was developed with AI assistance (Claude Code).