Node-native tests

The Node.js runtime ships a test runner. I use it. No jest, no vitest, no @types/jest. The runner is borp (TAP reporter, parallel by default), coverage is c8.

This is a single-tool-per-job choice: the standard library covers it, so no third-party test framework earns its place in package.json. The full ait testing setup — Docker test services, c8 invocation, package-mirroring test/ directory — is documented at personal/ait/references/best-practices-testing.md.

When this skill is active

You are about to:

• Add a test file
• Configure a test runner or coverage tool
• Migrate from another test framework (only if I asked for it)
• Reach for jest.mock, vi.mock, or @types/jest

The setup