How to use

_pickAndConcatResults

function

in

Array

async _getChannelsById(ids: Array<string>): Promise<Array<Object>> {
  const notCachedIds = ids.filter((id: string) => !this.channelsCache[id])

  // fetch unknown channels from API
  if (notCachedIds.length) {
   const predicate = `id in ("${notCachedIds.join('", "')}")`
   const channelService = this._createService('channels')
   const uri = channelService.where(predicate).build()

   const results = ProductJsonToCsv._pickAndConcatResults(
    await this.fetchReferences(uri)
   )
   results.forEach((result: Channel) => {
    // we should keep old channels in the cache because we can resolve
    // multiple products in parallel and we don't want to fetch same channels
    // multiple times
    this.channelsCache[result.id] = result
   })
  }

  // pick only requested channels from cache
  return pick(this.channelsCache, ids)
 }

// This method decides if to get the categories from cache or API
 _getCategories(ids: Array<string>): Promise<Array<Object>> {
  const notCachedIds = []
  const cachedCategories = []
  ids.forEach((id: string) => {
   if (this.categoriesCache[id])
    cachedCategories.push(this.categoriesCache[id])
   else notCachedIds.push(id)
  })
  if (!notCachedIds.length) return Promise.resolve(cachedCategories)

  const predicate = `id in ("${notCachedIds.join('", "')}")`
  const categoriesService = this._createService('categories')
  const uri = categoriesService.where(predicate).build()
  return this.fetchReferences(uri).then(
   (res: SuccessResult[]): Array<Category> => {
    const results = ProductJsonToCsv._pickAndConcatResults(res)
    results.forEach((result: Category) => {
     cachedCategories.push(result)
     this.categoriesCache[result.id] = result
    })
    return cachedCategories
   }
  )
 }

async _getCustomerGroupsById(ids: Array<string>): Promise<Array<Object>> {
  const notCachedIds = ids.filter(
   (id: string) => !this.customerGroupsCache[id]
  )

  // fetch unknown customerGroups from API
  if (notCachedIds.length) {
   const predicate = `id in ("${notCachedIds.join('", "')}")`
   const customerGroupService = this._createService('customerGroups')
   const uri = customerGroupService.where(predicate).build()
   const results = ProductJsonToCsv._pickAndConcatResults(
    await this.fetchReferences(uri)
   )

   results.forEach((result: CustomerGroup) => {
    // we should keep old customerGroups in the cache because we can resolve
    // multiple products in parallel and we don't want to fetch same customerGroups
    // multiple times
    this.customerGroupsCache[result.id] = result
   })
  }

  // pick only requested customerGroups from cache
  return pick(this.customerGroupsCache, ids)
 }

async _getChannelsById(ids: Array<string>): Promise<Array<Object>> {
  const notCachedIds = ids.filter((id: string) => !this.channelsCache[id])

  // fetch unknown channels from API
  if (notCachedIds.length) {
   const predicate = `id in ("${notCachedIds.join('", "')}")`
   const channelService = this._createService('channels')
   const uri = channelService.where(predicate).build()

   const results = ProductJsonToCsv._pickAndConcatResults(
    await this.fetchReferences(uri)
   )
   results.forEach((result: Channel) => {
    // we should keep old channels in the cache because we can resolve
    // multiple products in parallel and we don't want to fetch same channels
    // multiple times
    this.channelsCache[result.id] = result
   })
  }

  // pick only requested channels from cache
  return pick(this.channelsCache, ids)
 }

// This method decides if to get the categories from cache or API
 _getCategories(ids: Array<string>): Promise<Array<Object>> {
  const notCachedIds = []
  const cachedCategories = []
  ids.forEach((id: string) => {
   if (this.categoriesCache[id])
    cachedCategories.push(this.categoriesCache[id])
   else notCachedIds.push(id)
  })
  if (!notCachedIds.length) return Promise.resolve(cachedCategories)

  const predicate = `id in ("${notCachedIds.join('", "')}")`
  const categoriesService = this._createService('categories')
  const uri = categoriesService.where(predicate).build()
  return this.fetchReferences(uri).then(
   (res: SuccessResult[]): Array<Category> => {
    const results = ProductJsonToCsv._pickAndConcatResults(res)
    results.forEach((result: Category) => {
     cachedCategories.push(result)
     this.categoriesCache[result.id] = result
    })
    return cachedCategories
   }
  )
 }

async _getCustomerGroupsById(ids: Array<string>): Promise<Array<Object>> {
  const notCachedIds = ids.filter(
   (id: string) => !this.customerGroupsCache[id]
  )

  // fetch unknown customerGroups from API
  if (notCachedIds.length) {
   const predicate = `id in ("${notCachedIds.join('", "')}")`
   const customerGroupService = this._createService('customerGroups')
   const uri = customerGroupService.where(predicate).build()
   const results = ProductJsonToCsv._pickAndConcatResults(
    await this.fetchReferences(uri)
   )

   results.forEach((result: CustomerGroup) => {
    // we should keep old customerGroups in the cache because we can resolve
    // multiple products in parallel and we don't want to fetch same customerGroups
    // multiple times
    this.customerGroupsCache[result.id] = result
   })
  }

  // pick only requested customerGroups from cache
  return pick(this.customerGroupsCache, ids)
 }