Function createPersistence

packages/ai-client/tests/chat-client.test.ts:34–42

(
    storedMessages?: Array<UIMessage> | null,
  )

  }

  function createPersistence(
    storedMessages?: Array<UIMessage> | null,
  ): ChatClientPersistence {
    return {
      getItem: vi.fn(() => storedMessages),
      setItem: vi.fn(),
      removeItem: vi.fn(),
    }
  }

  function createDeferred<T>() {
    let resolve!: (value: T) => void