object appends chains

object-append-chain.js

Object.appendChain = function (oChain, oProto) {
    if (typeof oProto !== 'object' && typeof oProto !== 'string') {
        throw new TypeError('second argument must be an object or a string');
    }

    var oNewProto = oProto;
    var oReturn = o2nd = oLast = oChain instanceof this ? oChain : new oChain.constructor(oChain);

    for (var o1st = this.getPrototypeOf(o2nd); o1st !== Object.prototype && o1st !== Function.prototype; o1st = this.getPrototypeOf(o2nd)) {
        o2nd = o1st;
    }

    if (oProto.constructor === String) {
        oNewProto = Function.prototype;
        oReturn = Function.apply(null, Array.prototype.slice.call(arguments, 1));
        this.setPrototypeOf(oReturn, oLast);
    }    

    this.setPrototypeOf(o2nd, oNewProto);
    return oReturn;
};


function Mammal() {
    this.isMammal = 'yes';
}

function MammalSpecies(sMammalSpecies) {
    // Mammal.call(this);
    this.species = sMammalSpecies;
}

MammalSpecies.prototype = new Mammal();
MammalSpecies.prototype.constructor = MammalSpecies;

var oCat = new MammalSpecies('Felis');

function Animal() {
    this.breathing = 'yes';
  }

let ssss = Object.appendChain(oCat, new Animal());

console.log('cat: ', oCat.breathing);
console.log('cat: ', oCat.isMammal);

// ssss();