Agent skill · software engineering · secondsky
vitest-testing
Modern TypeScript/JavaScript testing with Vitest. Fast unit and integration tests, native ESM support, Vite-powered HMR, and comprehensive mocking. Use for testing TS/JS projects.
Why this skill is useful
Provides specific Vitest commands and configurations for testing JavaScript/TypeScript projects that the AI may not generate accurately on its own.
What it needs
Requires bun, npm installed locally. About 2k tokens when loaded. Last updated 2026-08-06. 204 stars on the source repository.
What this skill does
Vitest Testing Expert knowledge for testing JavaScript/TypeScript projects using Vitest - a blazingly fast testing framework powered by Vite. Quick Start Installation Configuration Running Tests Writing Tests Basic Structure Parametrized Tests Assertions Mocking Function Mocks Module Mocking Timers Coverage Integration Testing Best Practices One test file per source file: math.ts → math.test.ts Group related tests with describe() blocks Use descriptive test names Mock only external dependencies Use concurrent tests for independent async tests Share expensive fixtures with beforeAll() Aim for 80%+ coverage but don't chase 100% See Also test-quality-analysis - Detecting test smells playwright-testing - E2E testing mutation-testing - Validate test effectiveness
How to use it
Reference it in AdaL, Claude Code, Cursor or any coding agent — nothing to install:
@skills secondsky/vitest-testing