text: export const ADD_ARTICLE = `ADD_ARTICLES`;
  export const CLEAR_ARTICLES = `CLEAR_ARTICLES`;
  
  export default function(state = [], {type, article } ) {
      switch(type) {
          case CLEAR_ARTICLES:
              return [];
              
          case ADD_ARTICLE:
              return [
                  ...state,
                  article
              ];
  
          default:
              return state;
      }
  }
  