alternative for the deprecated __proto__

Object.getPrototypeOf

// old-way
obj.__proto__

// new-way
Object.getPrototypeOf(obj)

Why you dont use standard javascript function inheritance? For example:

function inherit(childClass, parentClass) {
    var f = function() {}; // defining temp empty function
    f.prototype = parentClass.prototype;
    f.prototype.constructor = f;

    childClass.prototype = new f;

    childClass.prototype.constructor = childClass; // restoring proper constructor for child class
    parentClass.prototype.constructor = parentClass; // restoring proper constructor for parent class
}


Employee = function Employee( /*list of constructor parameters, if needed*/ ) {}
Employee.prototype.paygrade = 1;
Employee.prototype.name = "";
Employee.prototype.dept = "general";
Employee.prototype.salary = function() {
    return this.paygrade * 30000;
}


WorkerBee = function WorkerBee( /*list of constructor parameters, if needed*/ ) {
    this.projects = ["Project1", "Project2"];
}
inherit(WorkerBee, Employee); // for this implementation of *inherit* must be placed just after defining constructor
WorkerBee.prototype.paygrade = 2;
WorkerBee.prototype.projects = null; // only literals and function-methods can properly initialized for instances with prototype


Engineer = function Engineer( /*list of constructor parameters, if needed*/ ) {}
inherit(Engineer, WorkerBee);
Engineer.prototype.dept = "Programming";
Engineer.prototype.language = "Objective-C";

var jane = new Engineer( /*Engineer parameters if needed*/ );
var jill = new Engineer( /*Engineer parameters if needed*/ );
var cow = new Employee( /*Employee parameters if needed*/ );