Builder design pattern javascript

builder-design-pattern-js.js

class Car {
    constructor(make, model, year, isForSale = true, isInStock = false) {
        this.make = make;
        this.model = model;
        this.year = year;
        this.isForSale = isForSale;
        this.isInStock = isInStock;
    }

    toString() {
        return console.log(JSON.stringify(this));
    }
}

class CarBuilder {
    constructor(make, model, year) {
        this.make = make;
        this.model = model;
        this.year = year;
    }

    notForSale() {
        this.isForSale = false;

        return this;
    }

    addInStock() {
        this.isInStock = true;

        return this;
    }

    build() {
        return new Car(this.make, this.model, this.year, this.isForSale, this.isInStock);
    }
}

module.exports = CarBuilder;

const CarBuilder = require('./CarBuilder');

const bmw = new CarBuilder('bmw', 'x6', 2020).addInStock().build();
const audi = new CarBuilder('audi', 'a8', 2021).notForSale().build();
const mercedes = new CarBuilder('mercedes-benz', 'c-class', 2019).build();

const bmw = new CarBuilder('bmw', 'x6', 2020, true, true);