Do Not Confuse Class and Instance Inheritance With TypeScript

ClassAndInstanceInheritance.ts

/**
 * Combined class and instance inheritance in TypeScript
 * This looks deceptively simple, but there are two layers of inheritance that's happening
 * One is the Class inheritance. Another is the actual instance inheritance that's chained
 * through the children array. The parent has its' instance based factory to generate its
 * own children either daughters of sons
 */
class person {
    constructor(name, parent = null) {
        this.name = name;
        this.parent = parent;
        this.children = [];
        // Do not instantiate subclass here. It will create a constructor loop
        // Try uncommenting the line below and see what happens
        // const s = new son("kyle", this);
    }
    create(name, kind) {
        if (kind === "daughter") {
            const c = new daughter(name, this);
            return c;
        }
        if (kind == "son") {
            const c = new son(name, this);
            return c;
        }
        return;
    }
    show() {
        return this.name;
    }
    toString() {
        return this.name ? this.name : "nobody";
    }
}
exports.person = person;
class daughter extends person {
    constructor(name, parent) {
        super(name, parent);
        parent.children.push(this);
    }
}
exports.daughter = daughter;
class son extends person {
    constructor(name, parent) {
        super(name, parent);
        parent.children.push(this);
    }
}
exports.son = son;
let p = new person("Kathy");
let d = p.create("Kim", "daughter");
let gd = d.create("Kerry", "daughter");
let s = p.create("Ken", "son");
console.log(`Parent ${p.show()} has ${p.children}`);
console.log(`Daughter ${d.show()} has ${d.children}`);
console.log(`${gd.show()}'s parent is ${gd.parent.show()}`);
console.log(`${gd.show()}'s grand parent is ${gd.parent.parent.show()}`);
console.log(`Son ${s.show()} has ${s.children.length ? s.children : "nobody"}`);