test-development Skill

1---2name: test-development3description: Test development. Use when adding or changing runtime Vitest coverage or Tstyche contracts for behavior, inference, assignability, or displayed public types.4---5 6Select every applicable branch before editing:7 8- **Runtime behavior:** Read [runtime.md](runtime.md).9- **Type contracts:** Read [types.md](types.md).10 11Some changes may require both branches. The task is complete when every12changed runtime behavior and type contract has focused coverage, targeted tests13pass, and applicable root checks pass or are reported as not runnable.14