Function applySuccessfulResult

packages/query-db-collection/src/query.ts:1243–1338

(
      queryKey: QueryKey,
      result: QueryObserverResult<any, any>,
      persistedBaseline?: Map<
        string | number,
        {
          value: any
          owners: Set<string>
        }
      >,
    )

    type UpdateHandler = Parameters<QueryObserver[`subscribe`]>[0]

    const applySuccessfulResult = (
      queryKey: QueryKey,
      result: QueryObserverResult<any, any>,
      persistedBaseline?: Map<
        string | number,
        {
          value: any
          owners: Set<string>
        }
      >,
    ) => {
      const hashedQueryKey = hashKey(queryKey)

      if (collection.status === `cleaned-up`) {
        return
      }

      // Clear error state
      state.lastError = undefined
      state.errorCount = 0

      const rawData = result.data
      const newItemsArray = select ? select(rawData) : rawData

      if (
        !Array.isArray(newItemsArray) ||
        newItemsArray.some((item) => typeof item !== `object`)
      ) {
        const errorMessage = select
          ? `@tanstack/query-db-collection: select() must return an array of objects. Got: ${typeof newItemsArray} for queryKey ${JSON.stringify(queryKey)}`
          : `@tanstack/query-db-collection: queryFn must return an array of objects. Got: ${typeof newItemsArray} for queryKey ${JSON.stringify(queryKey)}`

        console.error(errorMessage)
        return
      }

      const currentSyncedItems: Map<string | number, any> = new Map(
        collection._state.syncedData.entries(),
      )
      const shouldUsePersistedBaseline = persistedBaseline !== undefined
      const previouslyOwnedRows = shouldUsePersistedBaseline
        ? new Set(persistedBaseline.keys())
        : getHydratedOwnedRowsForQueryBaseline(hashedQueryKey)
      const newItemsMap = new Map<string | number, any>()
      newItemsArray.forEach((item) => {
        const key = getKey(item)
        newItemsMap.set(key, item)
      })

      begin()
      if (metadata) {
        metadata.collection.delete(
          `${QUERY_COLLECTION_GC_PREFIX}${hashedQueryKey}`,
        )
      }

      previouslyOwnedRows.forEach((key) => {
        const oldItem = shouldUsePersistedBaseline