Minimal Typescript Project Setup

Published 2020-12-20

I find that setting up a Typescript project usually takes some time, as it involves doing some googling to figure out how to set up all the tools. I figured I do it enough that its worth writing a quick reference for getting set up.

mkdir myproject
cd myproject
npm init

Once that is done, lets add some dependencies

npm i -D typescript ts-node @types/node

Now lets create a tsconfig.json to store our Typescript configuration

// tsconfig.json
{
  "compilerOptions": {
    "module": "commonjs",
    "strict": true,
    "outDir": "./dist"
  },
  "include": ["src/**/*"],
  "exclude": ["node_modules", "**/*.test.ts"]
}

This is a fairly minimal tsconfig.json that can be extended if need be.

Lets create an entrypoint for our program, create a new folder called src and create a file called main.ts inside it

// src/main.ts
console.log("Hello world!")

Now we will add some scripts to the package.json

// package.json
{
  ...
  "scripts": {
    "build": "tsc",
    "dev": "ts-node src/main.ts"
  }
}

Now you should be able to run npm run dev and see "Hello world!" printed to the screen.

Setting up testing with Jest (optional)

Its always good practise to write some tests, next lets add Jest to our project and configure it

npm i -D jest ts-jest @types/jest

Now lets create configuration file for Jest

// jest.config.js
module.exports = {
  preset: "ts-jest",
  testEnvironment: "node",
}

After that, add a entry in your package.json to execute the tests

// package.json
{
  ...
  "scripts": {
    ...
    "test": "jest"
  }
}

Next create a sample test to verify that Jest works correctly

// src/example.test.ts
test("sample test", () => {
  expect(1 + 1).toEqual(2)
})

Then run npm run test

If it all works correctly, you'll see the test output and the tests passing.