progress-reducer.js

const initialState = {
  visible: false,
  text: ""
};

export default (state = initialState, action) => {
  switch (action.type) {
    case "SHOW_PROGRESS":
      return {
        ...state,
        visible: true,
        text: action.text
      };
    case "HIDE_PROGRESS":
      return {
        ...state,
        visible: false,
        text: ""
      };

    default:
      return state;
  }
};