complex-traverse.js

const seen = []

function traverseObject(obj) {
  Object.keys(obj).reduce((acc, key) => {
    const value = obj[key];
    if (typeof value !== 'object) return { ...acc, [key]: value };
    
    if (Array.isArray(value) {
      return { ...acc, [key]: value.map(traverseObject) }
    }
    
    if (seen.indexOf(value) !== -1) {
      return { ...acc, [key]: 'cycle' }
    }
    
    const seenIndex = seen.push(node) - 1;
    const objValue = traverseObject(value)
    seen.splice(seenIndex, 1);
    return { ...acc, [key]: objValue }
  }, {});
}

copy van je obj, aj aj aj slooooooow!!!!! haha thanks tho