Hands-On Functional Programming with TypeScript

Working with Immer

We are going to take a look at another popular immutability library. The library is known as Immer, and it can be installed using the following npm command:

npm install immer

Immer allows us to define immutable classes using the readonly access modifier. This means that we can also create instances of our classes using a standard class constructor:

import produce from "immer";class Street {    public readonly num: number;    public readonly name: string;    public constructor(num: number, name: string) {        this.num = num;        this.name = name;    }}class Address {    public readonly city: string;    public readonly street: Street;    public constructor(city: string, street: Street) {        this.city = city;        this.street = street;    }}const address = new Address( ...