Function replaceEqualDeep

packages/query-core/src/utils.ts:288–334

(a: any, b: any, depth = 0)

 */
export function replaceEqualDeep<T>(a: unknown, b: T, depth?: number): T
export function replaceEqualDeep(a: any, b: any, depth = 0): any {
  if (a === b) {
    return a
  }

  if (depth > 500) return b

  const array = isPlainArray(a) && isPlainArray(b)

  if (!array && !(isPlainObject(a) && isPlainObject(b))) return b

  const aItems = array ? a : Object.keys(a)
  const aSize = aItems.length
  const bItems = array ? b : Object.keys(b)
  const bSize = bItems.length
  const copy: any = array ? new Array(bSize) : {}

  let equalItems = 0

  for (let i = 0; i < bSize; i++) {
    const key: any = array ? i : bItems[i]
    const aItem = a[key]
    const bItem = b[key]

    if (aItem === bItem) {
      copy[key] = aItem
      if (array ? i < aSize : hasOwn.call(a, key)) equalItems++
      continue
    }

    if (
      aItem === null ||
      bItem === null ||
      typeof aItem !== 'object' ||
      typeof bItem !== 'object'
    ) {
      copy[key] = bItem
      continue
    }

    const v = replaceEqualDeep(aItem, bItem, depth + 1)
    copy[key] = v
    if (v === aItem) equalItems++
  }

  return aSize === bSize && equalItems === aSize ? a : copy
}

/**
 * Shallow compare objects.