@atlaskit/editor-plugin-history/dist/es2019/editor-actions/reducer.js

History plugin for @atlaskit/editor-core

import { HistoryActionTypes } from './actions';
const reducer = (state, action) => {
  switch (action.type) {
    case HistoryActionTypes.UPDATE:
      return {
        canUndo: action.canUndo,
        canRedo: action.canRedo
      };
  }
  return state;
};
export default reducer;