NestJS Basics#9 - NestJS Middleware Functions

They are really useful

Welcome to the Part 9 of NestJS Basics.

In the previous post, we looked at the API Documentation using Swagger & NestJS. The main topics were as follows:

• What is Swagger?

• Initializing the Swagger module

• Setting the Proper API Tags

  • The role of generic interface

  • The catch() method

If you haven’t gone through it yet, you can check out the post on the NestJS Swagger integration below:

NestJS Basics#8 - API Documentation with Swagger

In today’s post, I’m going to cover the topic of middleware functions in NestJS.

The Plan

Here are the things we will cover in this post.

• What is a middleware function?

• How to apply a NestJS middleware function?

  • method-level

  • route wildcards

  • excluding routes

  • multiple middleware functions

• Class-based middleware to functional middleware

• Global middleware

As usual, every step will be accompanied by appropriate code examples.

Let’s begin.