Recursive Object.defineProperty() getters

Question

I'm trying to recursively assign the object values from class constructor argument as a properties of the class. Can't figure out how to do a recursion - getting 'Maximum call stack size exceeded' and infinity loops most of the time. Here is the demo:

const Locale = function(rules) {    
    for (let prop in rules) {
        Object.defineProperty(this, prop, {
            get: function () {
                console.log('getter for "%s" called', prop)
                return rules[prop];
            }
        });
    }
}

const rules = {
    a: {
        b: {
            c: 'value'
        }
    }
}

const locale = new Locale(rules);

console.log(locale.a.b.c);

Now I'm getting the following console output:

getter for "a" called
value

How to assign a getter for each level of the rules object? Expected console output:

getter for "a" called
getter for "b" called
getter for "c" called
value

Answer 1

You need to create a Locale object for each nested level of the rules object:

const Locale = function(rules) {    
    for (let prop in rules) {
        Object.defineProperty(this, prop, {
            get: function () {
                console.log('getter for "%s" called', prop);

                // create new Locale if object, return value if not an object
                if( rules[prop] !== null && typeof rules[prop] === 'object' )
                    return new Locale( rules[prop] );
                else
                    return rules[prop];
            }
        });
    }
}

const rules = {
    a: {
        b: {
            c: 'value'
        }
    }
}

const locale = new Locale(rules);
console.log(locale.a.b.c);