Redux persist automerge with immutable state

automergeLevel2-immutable.js

/* Created a custom automerge for immutable
  Adapted from https://github.com/rt2zz/redux-persist/blob/master/src/stateReconciler/autoMergeLevel2.js
*/

export default function autoMergeLevel2Immutable( 
  inboundState,
  originalState,
  reducedState,
  { debug }
) {

  let newState = { ...reducedState }
  // only rehydrate if inboundState exists and is an object
  if (inboundState && typeof inboundState === 'object') {
    Object.keys(inboundState).forEach(key => {
      // ignore _persist data
      if (key === '_persist') return
      // if reducer modifies substate, skip auto rehydration
      if (originalState[key] !== reducedState[key]) {
        if (process.env.NODE_ENV !== 'production' && debug)
          console.log(
            'redux-persist/stateReconciler: sub state for key `%s` modified, skipping.',
            key
          )
        return
      }
      if (isPlainEnoughObject(reducedState[key].toJS())) {
        // if object is plain enough shallow merge the new values (hence "Level2")
        newState[key] = newState[key].merge(inboundState[key])
        return
      }
      // otherwise hard set
      newState[key] = inboundState[key]
    })
  }

  if (
    process.env.NODE_ENV !== 'production' &&
    debug &&
    inboundState &&
    typeof inboundState === 'object'
  )
    console.log(
      `redux-persist/stateReconciler: rehydrated keys '${Object.keys(
        inboundState
      ).join(', ')}'`
    )

  return newState
}

function isPlainEnoughObject(o) {
  return o !== null && !Array.isArray(o) && typeof o === 'object'
}

Thanks for this!

If someone is using seamless-immutable the gist will not work as it's, you will need to change line 27 to use .asMutable() instead of .toJS()