get all object keys js

get-object-keys.js

const getObjectKeys = (obj, prefix = '') => {
  return Object.entries(obj).reduce((collector, [key, val]) => {
    const newKeys = [ ...collector, prefix ? `${prefix}.${key}` : key ]
    if (Object.prototype.toString.call(val) === '[object Object]') {
      const newPrefix = prefix ? `${prefix}.${key}` : key
      const otherKeys = getObjectKeys(val, newPrefix)
      return [ ...newKeys, ...otherKeys ]
    }
    return newKeys
  }, [])
}

/*
getObjectKeys({x: 1, y: 2, z: {a: 1, b: 2, c: { d: 1, e: 2 }}})
> ["x", "y", "z", "z.a", "z.b", "z.c", "z.c.d", "z.c.e"]
*/