Composition & concatenative inheritance.js

-- Human.js -----------------------------------------------------
const Human = () => ({
    name:'',
    health: 100,
    energy: 100,
    hunger: 0,
    age: 30,

    changeProp: function(pair) {
        this[Object.keys(pair)[0]] = Object.values(pair)[0];
    },
    getProp: function(key) {
        return this[key];
    },
});

module.exports = Human;


-- Scientist.js -----------------------------------------------------
const Human = require('./Human');

const maxAge = 60, minAge = 19;

const scientist = name => {
    let obj = Object.assign({}, Human());
    obj.changeProp({"age": Math.round(Math.random() * (maxAge - minAge) + minAge)});
    obj.name = name;
    let scienceObj = {
        experience: 'skin cancer',
        carrying: 'cellphone',
        talk: function() {
            console.log(`Well, my mane is ${this.name}, I'm ${this.age} years old and I know about ${this.experience}${this.carrying ? `. And I'm carry my ${this.carrying}` :'' }`);
        },
    };
    return Object.assign({}, obj, scienceObj);
};

module.exports = scientist;

-- main.js -----------------------------------------------------
const scientist = require("./scientist");

const Joe = scientist('Joe Mazzini');
Joe.talk();