根据 apollo 缓存中的键合并对象数组

如何解决根据 apollo 缓存中的键合并对象数组

我创建了一个辅助函数来使用 docs example 合并基于键的对象数组。它似乎工作正常，但我很好奇为什么默认情况下没有这样的辅助功能？也许有更简单的方法来做到这一点？

function mergeObjectsArray({
  existing,incoming,keyFieldNames,readField,mergeObjects,}: {
  existing: Record<string,string>[]
  incoming: Record<string,string>[]
  keyFieldNames: string[]
  readField: FieldFunctionoptions['readField']
  mergeObjects: FieldFunctionoptions['mergeObjects']
}) {
  if (existing.length === 0) return incoming

  // filter objects that's doens't have all keys
  const withKeys = (item: Record<string,string>) => {
    if (
      // filter if key doesn't exist = !keyFieldNames.some
      !keyFieldNames.some(key => {
        // Return false if some key doesn't exist
        if (readField(key,item)) return true

        return false
      })
    )
      return false

    return true
  }
  const e = existing.filter(withKeys)
  const i = incoming.filter(withKeys)

  // create new array
  const merged: Record<string,string>[] = e.slice(0)

  const itemsIndex: Record<string,number> = Object.create(null)

  const composeUniqueStrFromKeys = (item: Record<string,string>): string => {
    const keyFields = keyFieldNames.map(key => readField(key,item))

    return keyFields.join('_')
  }

  e.forEach((item,index) => {
    itemsIndex[composeUniqueStrFromKeys(item)] = index
  })

  i.forEach(item => {
    const composedKey = composeUniqueStrFromKeys(item)
    const index = itemsIndex[composedKey]

    if (typeof index === 'number') {
      // Merge the new item data with the existing data.
      merged[index] = mergeObjects(merged[index],item)
    } else {
      // First time we've seen this item in this array.
      itemsIndex[composedKey] = merged.length
      merged.push(item)
    }
  })

  return merged
}

const commentBookKeyFields = ['comment_uuid','book_id']

const typePolicies: InMemoryCacheConfig['typePolicies'] = {
  Query: {
    fields: {
      bookComments: {
        keyArgs: ['where','orderBy'],merge(existing = [],incoming = [],{ readField,mergeObjects }) {
          return mergeObjectsArray({ existing,keyFieldNames: commentBookKeyFields,mergeObjects })
        },},CommentBook: {
    keyFields: commentBookKeyFields,}