mapToType.js

const mapToType = (parent, depth = 2) => {
	const map = (object, lvl = 0) => {
    if (object instanceof Array) object = object[0];
		const props = {};
        for (let key in object) {
            const prop = object[key];
            let type = typeof prop;

            if (type === 'object') {
		type = prop instanceof Array ? 'array' : 'object';
                if ((lvl + 1) < depth && prop !== null) {
                  	props[key] = {};
			props[key][type] = mapToType(prop, lvl + 1);
			continue;
                }
	    	props[key] = prop === null ? null : type;
            } else {
                props[key] = type;
            }
        }
        return props
	}
  return map(parent);
}