# Testing

> TypeScript testing strategies and type-safe test practices

- Skill: `pluginagentmarketplace/testing-2` (Agent Skill, multi-file: 6 files)
- Install (CLI): `npx skillmds@latest add pluginagentmarketplace/testing-2`
- Raw SKILL.md: https://api.skillmd.com/api/skills/pluginagentmarketplace/testing-2/raw
- Safety review: pending
- Works with: Claude Code, Claude.ai, OpenAI Codex
- Category: Coding & Dev Tools, Integrations & APIs
- Author: pluginagentmarketplace (https://skillmd.com/u/pluginagentmarketplace)
- Updated: 2026-09-22
- Page: https://skillmd.com/skills/pluginagentmarketplace/testing-2

---


# TypeScript Testing Skill

## Overview
Master TypeScript testing including type-safe test setup, mocking with types, and testing type definitions.

## Topics Covered

### Test Setup
- Jest with ts-jest
- Vitest configuration
- ts-node for tests
- Path alias resolution
- Test coverage with types

### Type-Safe Mocking
- Typed mock functions
- jest.Mocked utility
- vi.fn() typing
- Mock implementations
- Partial mocking

### Type Testing
- tsd for type tests
- expect-type library
- Type assertion tests
- Compile-time testing
- Edge case type testing

### Testing Patterns
- Generic test utilities
- Type-safe fixtures
- Builder patterns for tests
- Custom matchers with types
- Assertion type narrowing

### Integration Testing
- API testing with types
- Database testing
- E2E type safety
- Request/response typing
- Test data factories

## Prerequisites
- TypeScript fundamentals
- JavaScript testing basics

## Learning Outcomes
- Write type-safe tests
- Test type definitions
- Create typed mocks
- Build test utilities