Здравейте, искам да попитам защо ми дава грешка, че полетата са "Read only" , когато пиша само getter-и без setter-и в клас на ES6?

Това ми е кода:

class BasePunchStarter {

    constructor(id,name,manufacturer,description,genres,targetPrice){
        if(new.target==BasePunchStarter){
            throw new TypeError("BasePunchStarter class cannot be instantiated directly!");
        }
        if(typeof id =="number") {
            //noinspection JSUnresolvedVariable
            this.id = id;
        }else throw new TypeError("ID must be a number!");
        if(typeof name=="string") {
            //noinspection JSUnresolvedVariable
            this.name = name;
        }else throw new TypeError("Name must be a string!");
        if(typeof manufacturer=="string") {
            //noinspection JSUnresolvedVariable
            this.manufacturer = manufacturer;
        }else throw new TypeError("Manufacturer must be a string!");
        if(typeof description=="string") {
            //noinspection JSUnresolvedVariable
            this.description = description;
        }else throw new TypeError("Description must be a string!");
        if(typeof genres=="Object"){
            //noinspection JSUnresolvedVariable
            this.genres=genres;
        }else new TypeError("Genres must be an Array of strings!");
        if(typeof targetPrice=="number") {
            //noinspection JSUnresolvedVariable
            this.targetPrice = targetPrice;
        }else new TypeError("Target price must be a number!");
        this.accumulatedMoney=0;
    }
    get accumulatedMoney(){
        return this._accumulatedMoney;
    }
    set accumulatedMoney(money){
        this._accumulatedMoney=money;
    }
    get id(){
        return this._id;
    }
    get name(){
        return this._name;
    }
    get manufacturer(){
        return this._manufacturer;
    }
    get description(){
        return this._description;
    }
    get genres(){
        return this._genres;
    }
    get targetPrice(){
        return this._targetPrice;
    }
}

module.exports = BasePunchStarter;
Използвам "//noinspection JSUnresolvedVariable" за да не ми пищи за грешката и няма проблем, но едва ли е най-добрият вариянт за справяне с проблема.