topics-actions.js

import _ from 'lodash';
import * as types from './actionTypes';
import redditService from '../../services/reddit';

export function fetchTopics() {
  return async(dispatch, getState) => {
    try {
      const subredditArray = await redditService.getDefaultSubreddits();
      const topicsByUrl = _.keyBy(subredditArray, (subreddit) => subreddit.url);
      dispatch({ type: types.TOPICS_FETCHED, topicsByUrl });
    } catch (error) {
      console.error(error);
    }
  };
}

Can you explain the use of the async keyword in line 6? That doesn't look like valid syntax to me. Is it meant to be an async arrow function?

It allows us to use await in the body of the function.