Immutable Set

imSet.js

const imSet = (objOrArray, path, valueOrFunc) => {
  const multipath = Array.isArray(path) && path.length > 1
  const pathItem = Array.isArray(path) ? path[0] : path // unwrap single item array
  const isFunc = typeof valueOrFunc === "function"

  const value = multipath
    ? imSet(objOrArray[pathItem], path.slice(1), valueOrFunc)
    : isFunc ? valueOrFunc(objOrArray[pathItem]) : valueOrFunc

  if (Array.isArray(objOrArray)) {
    return [
      ...objOrArray.slice(0, pathItem),
      value,
      ...objOrArray.slice(pathItem + 1),
    ]
  } else {
    return {
      ...objOrArray,
      [pathItem]: value,
    }
  }
}

export default imSet