deep delete objects (child first)

var o = {
    first: {
        a: 1,
        b: 2,
        c: {
            second: {
                a: 1,
                b: {
                    third: {
                        a: 1
                    }
                }
            }
        }
    },
    second: {
        a: 1,
        b: {
            second: {
                third: {
                    fourth: {
                        a: 1,
                        b: 2,
                        fifth: {
                            a: 1
                        }
                    }
                }
            }
        }
    }
}

function _isObject(val) {
    return typeof val == 'object';
}

function _destroyer(source,key,path) {
    delete source[key];
    console.log('destroyed ',path);
}

function deepDelete(obj, key, parent, path) {
    var p = path ? path +'.'+ key : key;

    if(!_isObject(obj)) {
        _destroyer(parent, key, p);
        return Object.keys(parent);
    }

    for(var i in obj) {
        if(obj.hasOwnProperty(i)) {
            if(!deepDelete(obj[i], i, obj, p)) {
                _destroyer(obj, i, p +'.'+ i);
            }
        }
    }

    if(key === 'ROOT') {
        return obj;
    }
}

deepDelete(o, 'ROOT');