@statesync/persistence

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@statesync/persistence / createSharedMemoryStorage

Function: createSharedMemoryStorage()

function createSharedMemoryStorage<T>(): object;

Defined in: persistence/src/storage/memory-storage.ts:370

Creates a shared in-memory storage registry that can be used to simulate multiple components or persistence layers sharing a common storage medium.

Each call to getBackend returns a StorageBackendWithMetadata instance scoped to the given key, but all backends share the same underlying Map store. This models the behavior of browser storage APIs where multiple parts of an application can read/write to the same storage under different keys.

Useful for integration tests that verify cross-component persistence behavior, such as one component saving state and another loading it.

Type Parameters

Type Parameter	Description
T	The type of the state data stored within snapshot envelopes.

Returns

An object with methods to obtain keyed storage backends and clear all data.

clearAll()

clearAll(): void;

Clears all data across every key in the shared storage.

Useful for cleanup in test afterEach or afterAll hooks to ensure test isolation.

Returns

void

getBackend()

getBackend(key): StorageBackendWithMetadata<T>;

Returns a StorageBackendWithMetadata instance scoped to the given key.

Multiple calls with the same key return backends that share the same data, simulating shared access to a single storage entry.

Parameters

Parameter	Type	Description
key	string	A unique string key identifying this storage entry.

Returns

StorageBackendWithMetadata<T>

A storage backend instance scoped to the specified key.

Example

const shared = createSharedMemoryStorage<MyState>();

const backendA = shared.getBackend('component-a');
const backendB = shared.getBackend('component-b');

await backendA.save({ revision: '1', data: { count: 1 } });
await backendB.save({ revision: '1', data: { count: 2 } });

// Each backend has its own isolated key
const snapshotA = await backendA.load();
const snapshotB = await backendB.load();

// Clear all shared data at once
shared.clearAll();