We know how to download a package and how to import it into our project. However, we will commonly need more than one package, with some specific versions. Should we memorize them to download manually each time we set up the project? No, now is the moment to create a package.json file.

This file is not only to map our dependencies; it must contain all the metadata about our project, and it serves as a quick documentation for which packages your project depends on. As minimal, the package.json should contain the following:

• Name: Project name, all lowercase with no blank spaces (you can use underscores if needed)
• Version: In the form of x.x.x

We can create this file manually, but NPM allows us to create it automatically by executing the following command:

$ npm init

The preceding command will prompt you with a bunch of questions that will be present in your package.json file. If you don't want to accept the defaults without being prompted any question, run the same command, adding a --yes flag at the end:

$ npm init --yes

Then, you will get a package.json file, as follows:

{
  "name": "my_package",
  "version": "1.0.0",
  "description": "",
  "main": "index.js",
  "scripts": {
    "test": "echo "Error: no test specified" && exit 1"
  },
  "repository": {
    "type": "git",
    "url": "https://github.com/package_owner/my_package.git"
  },
  "keywords": [],
  "author": "",
  "license": "ISC",
  "bugs": {
    "url": "https://github.com/package_owner/my_package/issues"
  },
  "homepage": "https://github.com/package_owner/my_package"
}