localstorage: ngrx 4 + prod

app.module.ts

export function localStorageSyncWrapper(reducer: any) {
  return localStorageSync({keys: ['filter', 'auth']}, reducer);
}

@NgModule({
  declarations: [
    AppComponent
  ],
  imports:      [
    StoreModule.forRoot(reducers, {metaReducers: [localStorageSyncWrapper]})
  ]
})
export class AppModule {
}

index.ts

export function localStorageSync(config: LocalStorageConfig, reducer: any) {

  if (config.storage === undefined) {
    config.storage = localStorage || window.localStorage;
  }

  if (config.storageKeySerializer === undefined) {
    config.storageKeySerializer = (key) => key;
  }

  const stateKeys = validateStateKeys(config.keys);
  const rehydratedState = config.rehydrate ? rehydrateApplicationState(stateKeys, config.storage, config.storageKeySerializer) : undefined;

  return function (state = rehydratedState, action: any) {
    /*
     Handle case where state is rehydrated AND initial state is supplied.
     Any additional state supplied will override rehydrated state for the given key.
     */
    if (action.type === INIT_ACTION && rehydratedState) {
      state = Object.assign({}, state, rehydratedState);
    }
    const nextState = reducer(state, action);
    syncStateUpdate(nextState, stateKeys, config.storage, config.storageKeySerializer, config.removeOnUndefined);
    return nextState;
  };
};