JSFiddle - React, Tailwind, and code Playground

JavaScript

var klass = function (obj, config_module) {
    if (config_module === 'constructor') {
        var object_public;
        if (obj.constructor) {
            object_public = obj.constructor;
            delete obj.constructor;
        }
        _.some(obj, function (val, key) {
            object_public.prototype[key] = val;
        });
        return object_public;
    }
};

var Test = klass({
    // instance, set in constructor
    A : 'instance',
    
    
    // static, not set in constructor
    B :  4,
    
    constructor: function (some_var) {
        this.A = some_var;
    },
    get: function () {
        return 2;
    },
    set: function () {
    }
}, 'constructor');


var instanceA = new Test('A');
var instanceB = new Test('B');

console.log('Start');
console.log(instanceA.A);
console.log(instanceB.A);