Heuristic:Promptfoo Promptfoo Warning Deprecated Cache Migration
| Knowledge Sources | |
|---|---|
| Domains | Caching, Migration, Deprecation |
| Last Updated | 2026-02-14 12:00 GMT |
Overview
Deprecation warning: the Cache_Migration module (src/cacheMigration.ts) is scheduled for complete removal after 2026-04-01.
Description
The entire cacheMigration module has a hard-coded sunset date of 2026-04-01. After this date, the migration logic is skipped entirely and new users start with a fresh cache. The code comments explicitly state: "TODO(2026-04-01): Remove this migration code after sunset date." This means the module, and its corresponding Implementation page, will become dead code after that date.
Usage
Consult this heuristic when maintaining or referencing the Cache_Migration implementation. After 2026-04-01, the module should be removed from the codebase and the corresponding wiki pages should be archived or deleted.
The Insight (Rule of Thumb)
- Action: Do not extend or build new features on top of the cache migration module.
- Value: Sunset date is 2026-04-01T00:00:00Z.
- Trade-off: After sunset, users who never ran the migration will lose their old cache entries and start fresh.
Reasoning
The cache migration was introduced to smooth the transition from cache-manager v4 (multiple JSON files) to keyv-file v7 (single JSON file). A 4-month migration window was deemed sufficient for active users to upgrade. After the sunset date, the migration code adds unnecessary complexity with no benefit.