The Ecosystem

An ecosystem of tools helps you manage dependencies, bundle code for production, test your applications, and maintain code quality.

# A typical project setup
npm init -y
npm install vite --save-dev
npm install eslint prettier --save-dev
npm install vitest --save-dev

This chapter gives an overview of the tools you will run into in real projects. You do not need to learn all of them right away. Knowing what they do and when to use them is enough to start, and it will make your work easier.

Tool Categories

Category Purpose Popular Tools
Package Management Install and manage dependencies npm, yarn, pnpm
Build Tools / Bundlers Dev server + production optimization Vite, Webpack, Rollup, esbuild
Testing Verify code correctness Jest, Vitest
Linting Catch errors and enforce style ESLint
Formatting Consistent code formatting Prettier

Why We Need These Tools

Package management manages dependencies for you, so you do not download libraries and track versions by hand.

Bundlers let browsers load applications with hundreds of modules efficiently.

Testing catches bugs during development instead of in production.

Linting and formatting keep codebases consistent and easier to maintain.

Learning Outcomes

  • Manage project dependencies with npm and alternative package managers, using semantic versioning and lock files to keep installs predictable
  • Set up a bundler, such as Vite or Webpack, and apply build optimizations to ship efficient production code
  • Write and organize unit and asynchronous tests, using mocks and best practices to build a reliable test suite
  • Enforce code quality and consistency with linting, formatting, and automated Git hooks

Sections

  1. Package Management with npm
  2. Semantic Versioning and Dependencies
  3. Alternative Package Managers
  4. Bundlers and Vite
  5. Webpack and Other Bundlers
  6. Build Optimization
  7. Testing with Jest
  8. Mocking and Async Testing
  9. Testing Best Practices
  10. Linting with ESLint
  11. Formatting with Prettier
  12. Integrating Linters, Formatters, and Git Hooks
  13. Practice Questions