walkObjectRecursive.js

function walkObjectRecursive(source, mapper = (v, k) => ({ [k]: v })) {
  if (typeof source !== 'object' || source === null || source === undefined) {
    return source
  }

  if (Array.isArray(source)) {
    return source.reduce((acc, val, index) => [...acc, mapper(walkObjectRecursive(val, mapper), index)], [])
  }

  return Object.keys(source).reduce(
    (acc, key) => ({
      ...acc,
      ...mapper(walkObjectRecursive(source[key], mapper), key),
    }),
    {},
  )
}