Test development. Use when adding or changing runtime Vitest coverage or Tstyche contracts for behavior, inference, assignability, or displayed public types.
Inspect nearby .tst.ts files and use their imports and assertion style. Use
ordinary Tstyche assertions such as toBe for structural equality and choose a
specific assertion for the inference or assignability contract under test.
Structural equality does not verify editor quick-info rendering. For internal
aliases, unsimplified intersections, or other displayed-type regressions, read
displayed-types.md.
Run targeted pnpm test-types <filename>; the root command covers every
configured TypeScript version. For a regression fix, confirm the assertion
fails against the pre-fix type. This branch is complete when the assertion
proves the intended contract and the target passes.
