redux-persist-state-manager v0.1.2

Redux Persist State Manager

Replacement for autoRehydrate with the following properties:

• state migrations
• hard set rehydrated values (no longer shallow merge)
• implemented as higher order reducer
• helpful log messages for common use case concerns

Usage

import stateManager from 'redux-persist-state-manager'
import _ from 'lodash'

// normal redux reducer
import rootReducer from './reducers'

const stateMigrations = {
  '1': (state) => ({}), // remove everything from stored state (fresh start)
  '2': (state) => _.pick(state, ['reducerA']), // keep only reducerA
  '3': (state) => _.omit(state, ['reducerB']), // remove reducerB from state
}

const VERSION = 3 // integer representation of the version of your state
const stateManagedReducer = stateManager(rootReducer, { version: VERSION }, stateMigrations)

How Migrations Work

Every time state manager loads it stores the current version (as defined at setup) in redux state. If the app later loads with a new version, state manager will run any migrations that are between the previously stored version and the latest version. For example:

// stored state: `{ version: 2,  counter: 100}`

const stateMigrations = {
  '1': (state) => ({}),
  '2': (state) => ({}),
  '3': (state) => { 
    state.counter = state.counter + 1
    return state
  }
}

const VERSION = 3
const stateManagedReducer = stateManager(rootReducer, { version: VERSION }, stateMigrations)

What happens:
1. redux-persist loads stored state
2. REHYDRATE action is dispatched
3. stateManager see the old version is 2 and the new version 3, and decides to run all migrations > 2 and <= 3
4. migration 3 is run which increments the counter
5. rehydrated state is now { version: 3, counter: 101 }

Injected Reducers Example

import { combineReducers } from 'redux'
import stateManager from 'redux-persist-state-manager'

const VERSION = 1
const stateMigrations = {
  '1': (state) => ({})
}
export const makeRootReducer = (asyncReducers) => {
  return stateManager(
    combineReducers(
      {
        core: coreLayoutReducer,
        ...asyncReducers
      }
    ),
    {
      version: VERSION
    },
    stateMigrations
  )
}