javascript-testing-patternslisted
Install: claude install-skill HermeticOrmus/claude-code-game-development
# 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:**
```typescript
// jest.config.ts
import type { Config } from 'jest';
const config: Config = {
preset: 'ts-jest',
testEnvironment: 'node',
roots: ['<rootDir>/src'],
testMatch: ['**/__tests__/**/*.ts', '**/?(*.)+(spec|test).ts'],
collectCoverageFrom: [
'src/**/*.ts',
'!src/**/*.d.ts',
'!src/**/*.interface.ts',
],
coverageThreshold: {
global: {
branches: 80,
functions: 80,
lines: 80,
statements: 80,
},
},
setupFilesAfterEnv: ['<rootDir>/src/test/setup.ts'],
};
export default config;
```
### Vitest - Fast, Vite-Native Testing
**Setup:**
```typescript
// vitest.config.ts
import { defineConfig } from 'vitest/config';
export default defineConfig({
test: {
globals: true,
environment: 'node',
coverage: {
provider: 'v8',
reporter: ['t