Agent skill · software engineering · sundial-org
test-gen
Generate unit tests from source files using AI. Use when adding test coverage.
Why this skill is useful
Generates meaningful unit tests for various frameworks, providing domain-specific knowledge on test generation that the AI wouldn't reliably produce on its own.
What it needs
About 1k tokens when loaded. Last updated 2026-03-07. 639 stars on the source repository.
What this skill does
Test Gen Your code has 12% test coverage and your manager is asking questions. This tool generates unit tests from your source files. Covers happy paths, edge cases, error conditions. Tests that actually test something, not just exist for coverage numbers. One command. Zero config. Just works. Quick Start What It Does Generates unit tests for your functions and classes Covers happy path, edge cases, and error conditions Creates tests for Jest, Vitest, or Mocha Mocks dependencies automatically Includes meaningful assertions, not just "expect(true).toBe(true)" Usage Examples Best Practices Review generated tests - AI tests are a starting point, not a finish line Run them immediately - Catch issues while context is fresh Add your own edge cases - You know your domain better than AI Don't trust coverage alone - Good tests test behavior, not lines When to Use This Inheriting a codebase with no tests Adding tests to a new feature quickly Hitting a coverage target for CI Learning what good tests look like for your code Part of the LXGIC Dev Toolkit This is one of 110+ free developer tools built by LXGIC Studios. No paywalls, no sign-ups, no API keys on free tiers. Just tools that work. Find more: GitHub: https://github.com/LXGIC-Studios Twitter: https://x.com/lxgicstudios Substack: https://lxgicstudios.substack.com Website: https://lxgicstudios.com Requirements No install needed. Just run with npx. Node.js 18+ recommended. How It Works The tool parses your source file, identifies testable units (functions, classes, methods), analyzes their signatures and implementations, then generates test cases that cover normal operation, edge cases, and error handling. License MIT. Free forever. Use it however you want. --- Built by LXGIC Studios GitHub: github.com/lxgicstudios/test-gen Twitter: @lxgicstudios
How to use it
Reference it in AdaL, Claude Code, Cursor or any coding agent — nothing to install:
@skills sundial-org/test-gen