Agent skill · software engineering · aiskillstore
javascript-testing-patterns
Implement comprehensive testing strategies using Jest, Vitest, and Testing Library for unit tests, integration tests, and end-to-end testing with mocking, fixtures, and test-driven development. Use when writing JavaScript/TypeScript tests, setting up test infrastructure, or implementing TDD/BDD workflows.
Why this skill is useful
Provides specific Jest and Vitest configurations and testing patterns that enhance the AI's ability to implement testing strategies in JavaScript/TypeScript applications.
What it needs
Requires jest, vitest installed locally. About 8k tokens when loaded. Last updated 2026-08-07. 405 stars on the source repository.
What this skill does
JavaScript Testing Patterns Comprehensive guide for implementing robust testing strategies in JavaScript/TypeScript applications using modern testing frameworks and best practices. When to Use This Skill Setting up test infrastructure for new projects Writing unit tests for functions and classes Creating integration tests for APIs and services Implementing end-to-end tests for user flows Mocking external dependencies and APIs Testing React, Vue, or other frontend components Implementing test-driven development (TDD) Setting up continuous testing in CI/CD pipelines Testing Frameworks Jest - Full-Featured Testing Framework Setup: Vitest - Fast, Vite-Native Testing Setup: Unit Testing Patterns Pattern 1: Testing Pure Functions Pattern 2: Testing Classes Pattern 3: Testing Async Functions Mocking Patterns Pattern 1: Mocking Modules Pattern 2: Dependency Injection for Testing Pattern 3: Spying on Functions Integration Testing Pattern 1: API Integration Tests Pattern 2: Database Integration Tests Frontend Testing with Testing Library Pattern 1: React Component Testing `typescript // components/UserForm.tsx import { useState } from 'react'; interface Props { onSubmit: (user: { name: string; email: string }) => void; } export function UserForm({ onSubmit }: Props) { const [name, setName] = useState(''); const [email, setEmail] = useState(''); const handleSubmit = (e: React.FormEvent) => { e.preventDefault(); onSubmit({ name, email }); }; return ( <form onSubmit={handleSubmit}> <input type="text" placeholder="Name" value={name} onChange={(e) => setName(e.target.value)} data-testid="name-input" /> <input type="email" placeholder="Email" value={email} onChange={(e) => setEmail(e.target.value)} data-testid="email-input" /> <button type="submit">Submit</button> </form> ); } // components/UserForm.test.tsx import { render, screen, fireEvent } from '@testing-library/react'; import { describe, it, expect, vi } from 'vitest'; import { UserForm } from './UserForm'; describe('UserForm …
How to use it
Reference it in AdaL, Claude Code, Cursor or any coding agent — nothing to install:
@skills aiskillstore/javascript-testing-patterns--a2cf13