mathieudutour / redux-storage-decorator-migrate

Migrate decorator for redux-storage to version the storage with migration

redux-storage-decorator-migrate

Migrate decorator for redux-storage to version the storage with migration

Installation

  npm install --save redux-storage-decorator-migrate

Usage

Versioned storage with migrations.

import migrate from 'redux-storage-decorator-migrate'

engine = migrate(engine, 3);
engine.addMigration(1, (state) => { /* migration step for 1 */ return state; });
engine.addMigration(2, (state) => { /* migration step for 2 */ return state; });
engine.addMigration(3, (state) => { /* migration step for 3 */ return state; });

Usage with redux-storage-decorator-filter and other decorators

import * as storage from 'redux-storage'
import createEngine from 'redux-storage-engine-localstorage'
import filter from 'redux-storage-decorator-filter'
import debounce from 'redux-storage-decorator-debounce'
import migrate from 'redux-storage-decorator-migrate'

const reducer = storage.reducer(reducers)
const stateVersionProp = '_stateVersion'
const whitelist = [stateVersionProp] // <-- Don't forget to whitelist your state version property
const blacklist = []
const engine = migrate(
  debounce(
    filter(
      createEngine('your.storage.identifier'),
      whitelist,
      blacklist
    ), 1000
  ), 0
)

// Your first migration:
engine.addMigration(1, (state) => { /* migration step for 1 */ return state; });

Testing migrations without a store (applying against ad-hoc state)

import {buildMigrationEngine} from 'redux-storage-decorator-migrate'
const versionKey = 'redux-storage-decorators-migrate-version'
 
const someTestState = {
  [versionKey]: 0,
  myFancyStateProperty: 'A'
}

const someExampleMigration = {
  version: 1,
  migration: (state) => ({...state, myFancyStateProperty: 'B'})
}

const migrationEngine = buildMigrationEngine(1, versionKey, [someExampleMigration])

const migratedState = migrationEngine(someTestState)

console.log(migratedState.myFancyStateProperty)
// B

Advanced Usage

Handling your migration engine explicitly:

import migrate, {buildMigrationEngine} from 'redux-storage-decorator-migrate'
const versionKey = 'redux-storage-decorators-migrate-version'

const migrations = [{
  version: 1,
  migration: (state) => ({ /* migration step for 1 */ return state; })
}, {
  version: 2,
  migration: (state) => ({ /* migration step for 2 */ return state; })
}]

const migrationEngine = buildMigrationEngine(1, versionKey, migrations)

engine = migrate(engine, 3, versionKey, migrations, migrationEngine);
engine.addMigration(3, (state) => { /* migration step for 3 */ return state; }); // still possible

// Migrate redux's initialState if provided
const migratedInitialState = migrationEngine(initialState || {});

// Redux store creation
const reduxStore = createStore(reduxStorage.reducer(combineReducers(reducers)), migratedInitialState, compose(...enhancers));

License

MIT