Setting up a new Typescript project

15.09.2021 — nodejs, typescript, yarn — 1 min read

- by Nick Grealy

Background:

Want to setup a typescript project from scratch, using the current best practices.

Steps to deploy

1. Install Typescript in a new project

init.sh

1npm init
2echo 'console.log("hello world")' > index.ts
3npm i -D typescript tslint ts-node nodemon dotenv dotenv-cli @types/node
4./node_modules/.bin/tslint --init

2. Update start scripts

package.json

1"scripts": {
2    "build": "tsc --build",
3    "build:clean": "tsc --build --clean",
4    "start": "node dist/index.js",
5    "start:dev": "dotenv -e .env ts-node index.ts",
6    "start:watch": "dotenv -e .env nodemon index.ts",
7  }

3. Setup nodemon

nodemon.json

1{
2  "watch": ["src"],
3  "ext": "ts,js,json",
4  "ignore": ["src/**/*.spec.ts"],
5  "exec": "ts-node ./src/index.ts"
6}

4. Setup tests

Install dependencies (recommend nock for external apis).

runme.sh

1npm i -D ts-mocha mocha chai jest @types/mocha sinon supertest

Setup test scripts.

package.json

1"test": "ts-mocha --timeout 10000 --recursive './test/**/*.test.ts'",
2"test-watch": "nodemon --watch test --watch src --exec 'ts-mocha --timeout 10000 --recursive --bail'  './test/**/*.test.ts'",
3"test-wip": "nodemon --watch test --watch src --exec 'ts-mocha --timeout 10000 --recursive --grep wip'  './test/**/*.test.ts'",

An example test.

test/myfirsttest.test.ts

1const { expect } = require('chai')
2const { describe, it, beforeEach, afterEach } = require('mocha')
3const sinon = require('sinon')
4const request = require('supertest')
5const express = require('express')
6
7export { };
8
9describe.skip('SomeFeature', () => {
10  describe('SomeUserStory', () => {
11    let app = null
12
13    // before each test...
14    beforeEach(() => {
15      sinon.restore()
16      // exampe stubbing
17      sinon.stub(utils, 'writeConfigSync').returns({})
18      sinon.stub(ServiceRegistry.prototype, 'init').resolves()
19    })
20
21    // after each test...
22    afterEach(() => {
23      sinon.restore()
24    })
25
26    // errors
27
28    it('SomeUserScenario', async function () {
29      const response = await request(app).get('/status')
30        .expect('Content-Type', /json/)
31        .expect(401)
32      expect(response.body).to.eql({ message: 'Unauthorised - please provide a token.' })
33      sinon.assert.notCalled(ServiceRegistry.prototype.addService)
34    })
35
36  })
37})

5. Setup eslint

TODO - complete