undo_redo.js

export const ({ shouldRecord, invertAction, isUndo, isRedo }) => {
  const history = []
  
  return store => next => action => {
    if (isUndo(action)) {
      const invert = invertAction(lastUndoable(history))
      history.push(invert)
      next(invert)
      return
    }

    if (isRedo(action)) {
      const invert = invertAction(lastRedoable(history))
      history.push(invert)
      next(invert)
      return
    }

    
    if (shouldRecord(action)) {
      history.push(action)
    }
    next(action)
  }
}