Storage.combine

Combines multiple Storage adapters into one.

Reads return the first non-null result; writes propagate to every storage. Failures during reads or writes are isolated via Promise.allSettled so a single failing backend will not break the others.

A common use case is layering an in-memory cache in front of a persistent backend, or mirroring writes between cookies and localStorage so server-rendered code can see what the client wrote.

Usage

import { Provider, Storage } from 'accounts'
 
const provider = Provider.create({
  storage: Storage.combine(Storage.cookie(), Storage.localStorage()),
})

Parameters

storages

• Type: readonly Storage[]
• Required

The storage adapters to combine, in priority order. The first storage that returns a non-null value for getItem wins. setItem and removeItem are dispatched to every storage in parallel.

import { Provider, Storage } from 'accounts'
 
const provider = Provider.create({
  storage: Storage.combine( 
    Storage.memory(), 
    Storage.idb(), 
  ), 
})