Chapter 1. Introduction

Every web developer relies heavily on one web framework or another (sometimes more if their services have different requirements) and companies will rely on many frameworks, but each has its own pros and cons. These frameworks provide just that, a frame for developers to build on top of, providing the basic functionality that any web framework must provide in order to be considered as a good choice for a developer or company to use in their tech stack. In this book, we will talk about many of those parts of the framework you would expect to see in a progressive framework such as Nest. These include:

1. Dependency Injection
2. Authentication
3. ORM
4. REST API
5. Websockets
6. Microservices
7. Routing
8. Explanation of Nest specific tools
9. OpenApi (Swagger) Documentation
10. Command Query Responsibility Segregation (CQRS)
11. Testing
12. Server-side rendering with Universal and Angular.

Nest provides more of these features because it is a modern web framework built on top of a Node.js Express server. By leveraging the power of modern ES6 JavaScript for flexibility and TypeScript to enforce type safety during compile time, Nest helps bring scalable Node.js servers to a whole new level when designing and building server-side applications. Nest combines three different techniques into a winning combination that allows for highly testable, scalable, loosely coupled and maintainable applications. These are:

1. Object-Oriented Programming (OOP): A model that builds around objects instead of actions and reusability rather than niche functionality.
2. Functional Programming (FP): The designing of determinate functionality that does not rely upon global states, ie. a function f(x) returns the same result every time for some set parameters that do not change.
3. Functional Reactive Programming (FRP): An extension of FP from above and Reactive programming. Functional Reactive Programming is at its core Functional Programming that accounts for a flow across time. It is useful in applications such as UI, simulations, robotics and other applications where the exact answer for a specific time period may differ from that of another time period.