Week1: NPM & Package-lock.json

How to install npm

When you install nodejs you will get npm along with it
https://nodejs.org/en/download/

To check node and npm version

node -v
npm -v

NPM stands for Node Package Manager

• it is a package manager for Javascript

The uses of npm are

• It is an online repository for the publishing of open-source Node.js projects

FOR EXAMPLE:
if you want to import the testing framework you can just install it by

npm install --save-dev jest

• It is a command-line utility for package installation, version management, and dependency management.

FOR EXAMPLE:
if you have module @jest/core, you can update to the latest version by

npm install @jest/core@latest

Once you install the library, it will store in node_modules

Normally, node_modules gonna be a big folder, so you do not push it into git.

It is recommended to have package.json and package-lock.json, to help you know those libraries and their versions

To create a package.json file

npm init

Package.json - list the version of its dependencies (library we install), and also other project information such as name, version, author, script, etc.

Package-lock.json - list solely about the dependencies in depth

Now when you want to install those libraries, npm can get the info from package-lock.json

To install dependencies just run:

npm install

Also keep in mind that:

• You can have only package.json
• But you can not have only package-lock.json file

package-lock.json have to come with package.json

** And both files need to be stored in git

Reference:
https://nodejs.org/en/knowledge/getting-started/npm/what-is-npm/
https://stackoverflow.com/questions/45052520/do-i-need-both-package-lock-json-and-package-json#:~:text=No.-,The%20package.,to%20a%20specific%20version%20number.