Passport

Passport is a well known library that is popular and flexible to use. In fact, passport is flexible middleware that can be fully customized. Passport allows different ways to authenticate a user like the following:

• local strategy that allows you to authenticate a user just with it’s own data email and password in most cases.
• jwt strategy that allows you to authenticate a user by providing a token and verifying this token using jsonwebtoken. This strategy is used a lot.

Some strategies use the social network or Google in order to authenticate the user with a profile such as googleOAuth, Facebook, or even Twitter.

In order to use passport you have to install the following package: npm i passport. Before you see how to implement the authentication, you must implement the userService and the userModel.