From Scratch - Node.js application

CLI tools

Node Version Manager (nvm)
Node.js (node, npm, npx)

Node.js packages

Typescript (typescript, @types/node)
TS Node (ts-node)
Nodemon (nodemon)
ESLint (eslint)
Jest (jest, ts-jest, @types/jest)
Dotenv (dotenv)

Install Node Version Manager (nvm)

Read more about how to install nvm here: https://github.com/nvm-sh/nvm

This is an example of how to install nvm on MacOS:

curl -o- https://raw.githubusercontent.com/nvm-sh/nvm/v0.39.3/install.sh | bash

nvm --version

Install Node.js (node, npm, npx)

nvm install --lts
nvm ls
nvm use 18

node --version
npm --version

Configure new Node.js application

mkdir FSNodeApp
cd FSNodeAPP
npm init -y

This creates the file package.json. Edit this file to change name, version and description.

Read more aboute package.json here: https://docs.npmjs.com/cli/v9/configuring-npm/package-json

Install Node.js packages

npm install typescript --save-dev
npm install @types/node --save-dev
npm install ts-node --save-dev
npm install nodemon --save-dev
npm install eslint --save-dev
npm install jest --save-dev
npm install ts-jest --save-dev
npm install @types/jest --save-dev
npm install dotenv

Configure Typescript

npx tsc --init --rootDir src --outDir dist

This creates the file tsconfig.json.

Read more about tsconfig.json here: https://www.typescriptlang.org/docs/handbook/tsconfig-json.html

Configure ESLint

npm init @eslint/config

Answer the questions about your coding style. This creates the file .eslintrc.json.

Read more about .eslintrc.json here: https://eslint.org/docs/latest/use/configure/

Configure Jest

touch jest.config.json

Edit jest.config.json:

{
    "preset": "ts-jest",
    "testEnvironment": "node",
    "testMatch": [ "*/__tests__/**/*.ts?(x)", "**/?(*.)+(spec|test).ts?(x)" ]
}

Read more about jest.config.json here: https://jestjs.io/docs/configuration

Update package.json

...
"scripts": {
    "build": "tsc",
    "dev": "nodemon ./src/index.ts",
    "start": "ts-node ./src/index.ts",
    "lint": "eslint --ext .ts .",
    "test": "jest"
}
...

Create app source code

mkdir src
touch src/index.ts:

Edit src/index.ts:

dotenv.config();

export function getHelloMessageFromEnv(): string {
    return process.env.HELLO_MESSAGE as string;
}

export function getHelloMessage(): string {
    return 'Hello World from function!';
}
console.log('Hello World!');

Create app environment file

tounch .env

Edit .env:

HELLO_MESSAGE=Hello World from environment file!

Create tests

mkdir src/tests
touch src/tests/first.test.ts

Edit src/tests/first.test.ts:

import { getHelloMessage, getHelloMessageFromEnv } from '..';

test('gets correct hello mesage from function', () => {
    expect(getHelloMessage()).toBe('Hello World from function!');
});

test('gets correct hello mesage from .env', () => {
    expect(getHelloMessageFromEnv()).toBe('Hello World from environment file!');
});

Build, run, analyse and test

Build app:

npm run build

Run app once:

npm run start

Run app and continuously check for changes:

npm run dev

Run code analysis:

npm run lint

Run tests:

npm run lint

wmjoers/FSNodeApp