javascript-testing-patternslisted
Install: claude install-skill Adnova-Group/muster
# 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: [