test: improve coverage for low-coverage modules (target 90%+ across the board) #126
Description
Several modules are below the 85% branch coverage threshold or have significant gaps. Raising coverage prevents regressions and improves confidence in refactors.
Low Coverage Modules (branches < 80%)
| Module | Statements | Branches | Functions | Lines |
|---|---|---|---|---|
| `src/index.js` | 89% | 74% | 62% | 89% |
| `src/api/server.js` | 83% | 76% | 82% | 85% |
| `src/api/routes/auth.js` | 81% | 75% | 90% | 84% |
| `src/api/routes/guilds.js` | 86% | 70% | 95% | 88% |
| `src/api/utils/redisClient.js` | 50% | 67% | 75% | 43% |
| `src/api/ws/logStream.js` | 79% | 74% | 68% | 81% |
| `src/modules/config.js` | 90% | 69% | 95% | 90% |
| `src/modules/ai.js` | 87% | 62% | 89% | 88% |
| `src/modules/rateLimit.js` | 90% | 68% | 71% | 91% |
| `src/modules/welcome.js` | 79% | 69% | 71% | 82% |
| `src/modules/triage.js` | 84% | 75% | 66% | 88% |
| `src/modules/starboard.js` | 79% | 83% | 100% | 78% |
Subtasks
- `redisClient.js` — Mock Redis connection states, test fallback behavior (43% lines → 85%+)
- `ai.js` — Test edge cases: token limits, streaming failures, thread reuse (62% branches → 85%+)
- `config.js` — Test config merge, nested key access, invalid input (69% branches → 85%+)
- `welcome.js` — Test DM failures, missing channel, disabled state (69% branches → 85%+)
- `rateLimit.js` — Test memory cap eviction, mute escalation (68% branches → 85%+)
- `guilds.js` — Test pagination, permission checks, channel listing (70% branches → 85%+)
- `logStream.js` — Test WebSocket lifecycle, auth failures, reconnection (74% branches → 85%+)
- `triage.js` — Test buffer overflow, concurrent eval, abort handling (75% branches → 85%+)
- `auth.js` — Test OAuth flow edge cases, token refresh, session expiry (75% branches → 85%+)
Acceptance Criteria
- All listed modules above 85% branch coverage
- No test relies on implementation details (test behavior, not internals)
- Tests run in <10s total (no slow network mocks)