TypeScript With ts-node-dev

Sample commands to init a NodeJS TypeScript project

Dependencies

yarn add typescript ts-node ts-node-dev @types/node --dev

npm i typescript ts-node ts-node-dev @types/node --save-dev

tsconfig.json

Create tsconfig.json in the root directory that will contain your typescript compiler configuration, more information in https://www.typescriptlang.org/docs/handbook/tsconfig-json.html

{
  "compilerOptions": {
    "target": "es2017", 
    "experimentalDecorators": true, 
    "emitDecoratorMetadata": true, 
    "module": "commonjs",
    "rootDir": "./src", 
    "outDir": "./dist", 
    "removeComments": true, 
    "esModuleInterop": true, 
    "forceConsistentCasingInFileNames": true, 
    "strict": true, 
    "resolveJsonModule": true,
    "skipLibCheck": true 
  }
}

According to our configuration you should write your code in src/ folder and should have an entry point file called index.ts inside.

package.json

Add dev and build scripts to your package.json file,

Dev: Uses ts-node-dev to start a dev server that automatically transpiles your .ts files to .js whenever you edit something. (More info at https://www.npmjs.com/package/ts-node-dev)
Build: Uses tsc to transpile your whole application to .js, is used when you want to deploy to production. (More info at https://www.typescriptlang.org/docs/handbook/compiler-options.html)

"scripts": {
    "build": "tsc",
    "dev": "ts-node-dev --respawn --transpile-only --ignore-watch node_modules --no-notify src/index.ts"
  }

NPM Package

If you are writing a npm package specify main and types path and add --declaration to your build script in order to generate types suggestions to who is using your package.

package.json

"main" : "dist/index.js",
"types" : "dist/index.d.ts",
"scripts": {
    "build": "tsc --declaration"
  }

Run

npm run dev

yarn dev

Build

npm run build

yarn build