Function createLocalStorageSync

packages/db/src/local-storage.ts:691–874

* Internal function to create localStorage sync configuration * Creates a sync configuration that handles localStorage persistence and cross-tab synchronization * @param storageKey - The key used for storing data in localStorage * @param storage - The storage API to use (localStorage, sessionStor

(
  storageKey: string,
  storage: StorageApi,
  storageEventApi: StorageEventApi,
  parser: Parser,
  _getKey: (item: T) => string | number,
  lastKnownData: Map<string | number, StoredItem<T>>,
)

 * @returns Sync configuration with manual trigger capability
 */
function createLocalStorageSync<T extends object>(
  storageKey: string,
  storage: StorageApi,
  storageEventApi: StorageEventApi,
  parser: Parser,
  _getKey: (item: T) => string | number,
  lastKnownData: Map<string | number, StoredItem<T>>,
): SyncConfig<T> & {
  manualTrigger?: () => void
  collection: any
  confirmOperationsSync: (mutations: Array<any>) => void
} {
  let syncParams: Parameters<SyncConfig<T>[`sync`]>[0] | null = null
  let collection: any = null

  /**
   * Compare two Maps to find differences using version keys
   * @param oldData - The previous state of stored items
   * @param newData - The current state of stored items
   * @returns Array of changes with type, key, and value information
   */
  const findChanges = (
    oldData: Map<string | number, StoredItem<T>>,
    newData: Map<string | number, StoredItem<T>>,
  ): Array<{
    type: `insert` | `update` | `delete`
    key: string | number
    value?: T
  }> => {
    const changes: Array<{
      type: `insert` | `update` | `delete`
      key: string | number
      value?: T
    }> = []

    // Check for deletions and updates
    oldData.forEach((oldStoredItem, key) => {
      const newStoredItem = newData.get(key)
      if (!newStoredItem) {
        changes.push({ type: `delete`, key, value: oldStoredItem.data })
      } else if (oldStoredItem.versionKey !== newStoredItem.versionKey) {
        changes.push({ type: `update`, key, value: newStoredItem.data })
      }
    })

    // Check for insertions
    newData.forEach((newStoredItem, key) => {
      if (!oldData.has(key)) {
        changes.push({ type: `insert`, key, value: newStoredItem.data })
      }
    })

    return changes
  }

  /**
   * Process storage changes and update collection
   * Loads new data from storage, compares with last known state, and applies changes