Setup & tsconfig Basics

Setup & tsconfig Basics

TypeScript is installed as a development dependency. The compiler (tsc) reads a tsconfig.json file at the root of your project to understand how to compile your code.

// Install TypeScript
// npm install --save-dev typescript
// npx tsc --init   (generates tsconfig.json)

A tsconfig.json controls the compiler. The most important options live under compilerOptions. Here is a sensible baseline for modern projects.

// tsconfig.json (JSON, not TypeScript — shown here for illustration)
// {
//   "compilerOptions": {
//     "target": "ES2022",
//     "module": "NodeNext",
//     "moduleResolution": "NodeNext",
//     "strict": true,
//     "outDir": "dist",
//     "rootDir": "src",
//     "esModuleInterop": true,
//     "skipLibCheck": true
//   },
//   "include": ["src"]
// }

Key compiler options explained

• target — the JavaScript version emitted (e.g. ES2022)
• module — the module system used in output (e.g. NodeNext, ESNext, CommonJS)
• strict — enables the full suite of strict type checks
• outDir — where compiled JavaScript files are written
• rootDir — the root of your TypeScript source files
• esModuleInterop — allows default imports from CommonJS modules