Sample commands to init a NodeJS TypeScript project

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

OR

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

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.

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" }

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" }

npm run dev 

OR

yarn dev 

npm run build 

or

yarn build