unit-test

name	unit-test
description	Applies project unit test conventions with Vitest and @solidjs/testing-library. Use when writing or editing .spec.ts files, including DOM tests, module mocking, assertions, async/error handling, and time-based tests.

Unit Test

Open and apply the reference files for the relevant section before working.

Core Rules

1. If tests already exist, verify current results first with Wallaby MCP, then Vitest if needed; fix existing failures before adding tests.
2. Use Vitest, and use @solidjs/testing-library for Solid.js DOM tests.
3. Place tests in the target directory's __tests__ folder and name files {targetFileName}.spec.ts.
4. Start test names with should, and split multi-function targets with describe blocks.
5. Do not modify the code under test by default. If the target is hard to unit test because logic is embedded in CLI, UI, I/O, or lifecycle code, ask whether to first extract the behavior into pure, importable logic functions, then test those functions and keep only smoke coverage for the wrapper.
6. For DOM tests, add /** @vitest-environment jsdom */ at the top of the file.
7. Aim for 100% coverage; when impossible, add ignore comments and document the reason.
8. Verify tests and coverage after changes, then fix lint issues.
9. See ./rules/assertion-patterns.md and ./examples/module-mocking.md for assertion and mocking examples.
10. See ./examples/async-assertion.md, ./examples/error-assertion.md, and ./examples/time-based-testing.md for specialized patterns.