rubico/dist/x/defaultsDeep.es.js

[a]synchronous functional programming

/**
 * rubico v2.6.2
 * https://github.com/a-synchronous/rubico
 * (c) 2019-2024 Richard Tong
 * rubico may be freely distributed under the MIT license.
 */

const isArray = Array.isArray

const arrayDefaultsDeepFromArray = function (array, defaultArray) {
  const defaultArrayLength = defaultArray.length,
    result = array.slice()
  let index = -1
  while (++index < defaultArrayLength) {
    const item = array[index],
      defaultItem = defaultArray[index]
    if (isArray(item) && isArray(defaultItem)) {
      result[index] = arrayDefaultsDeepFromArray(item, defaultItem)
    } else if (item == null) {
      result[index] = defaultItem
    } else if (defaultItem == null) {
      result[index] = item
    } else if (item.constructor == Object && defaultItem.constructor == Object) {
      result[index] = objectDefaultsDeepFromObject(item, defaultItem)
    } else {
      result[index] = item
    }
  }
  return result
}

const objectDefaultsDeepFromObject = function (object, defaultObject) {
  const result = { ...object }
  for (const key in defaultObject) {
    const item = object[key],
      defaultItem = defaultObject[key]
    if (isArray(item) && isArray(defaultItem)) {
      result[key] = arrayDefaultsDeepFromArray(item, defaultItem)
    } else if (item == null) {
      result[key] = defaultItem
    } else if (defaultItem == null) {
      result[key] = item
    } else if (item.constructor == Object && defaultItem.constructor == Object) {
      result[key] = objectDefaultsDeepFromObject(item, defaultItem)
    } else {
      result[key] = item
    }
  }
  return result
}

const defaultsDeep = defaultCollection => function defaulting(value) {
  if (isArray(value) && isArray(defaultCollection)) {
    return arrayDefaultsDeepFromArray(value, defaultCollection)
  }
  if (value == null || defaultCollection == null) {
    return value
  }
  if (value.constructor == Object && defaultCollection.constructor == Object) {
    return objectDefaultsDeepFromObject(value, defaultCollection)
  }
  return value
}

export default defaultsDeep