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Warren Wong
Warren Wong

Posted on • Originally published at warrenwong.org on

Setting Up TypeScript for Node

#typescript #javascript #node

Today, I wanted to go over how to set up a TypeScript project for NodeJS from scratch.

It's something that I do fairly often and so it's nice to have this as a starter repo for some of my future NodeJS projects.

Let's first create a new directory for this project. I'll just call it ts-node-demo for now, but you can just rename it at a later date when you use it to start a new project.

mkdir ts-node-demo cd ts-node-demo
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Let's make this a git repository and use yarn for our package manager. It'll be a good idea not to commit any of our dependencies into our repo as well.

git init yarn init echo node_modules/ > .gitignore
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Now I'll add the most basic dependencies for our TypeScript NodeJS project. Rather than doing an explicit build step and then running the plan JavaScript file that is a result of that build, I want to use the ts-node library that will take care of that for me. I'll, of course, also add TypeScript as well as the type definitions for NodeJS.

yarn add ts-node typescript @types/node
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It'll be nice if I didn't have to restart the dev server everytime I save a file so let's add ts-node-dev. If you've ever worked with nodemon, this is pretty much the same, but for TypeScript.

yarn add -D ts-node-dev
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package.json

{ "name": "ts-node-demo", "version": "1.0.0", "main": "index.js", "author": "Warren Wong<me@warrenwong.org>", "license": "MIT", "dependencies": { "@types/node": "^12.0.4", "ts-node": "^8.2.0", "typescript": "^3.5.1" }, "devDependencies": { "ts-node-dev": "^1.0.0-pre.39" } }
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I'll update the package.json to reflect the change to using TypeScript by changing index.js to index.ts. I should go ahead and create that file as well.

touch index.ts
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Now let's add some scripts for starting the production app as well as starting the dev server. Since a service like Heroku would use yarn start or npm start to start the production server, I'll go ahead define "start" as "yarn ts-node index.ts". To start the dev server, I want to just type yarn dev, so I'll define "dev" as "yarn ts-node-dev index.ts".

package.json

{ "name": "ts-node-demo", "version": "1.0.0", "main": "index.ts", "author": "Warren Wong <me@warrenwong.org>", "license": "MIT", "dependencies": { "ts-node": "^8.2.0", "typescript": "^3.5.1" }, "devDependencies": { "@types/node": "^12.0.4", "ts-node-dev": "^1.0.0-pre.39" }, "scripts": { "start": "yarn ts-node index.ts", "dev": "yarn ts-node-dev index.ts" } }
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Now to check if everything worked out, I'll need index.ts to actually do something.

index.ts

console.log("Hello, World!");
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Okay, time to test this out.

yarn dev Using ts-node version 8.2.0, typescript version 3.5.1 Hello, World! yarn start Hello, World!
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Top comments (2)

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nickytonline profile image
Nick Taylor •

I wasn't aware of ts-node-dev. I had always used ts-node with nodemon. Thanks for sharing!

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jdforsythe profile image
Jeremy Forsythe •

If you are planning on publishing npm modules with Typescript, I have a helpful starter repo you may find useful. github.com/jdforsythe/typescript-n...