Dynamically Load `hears` from External JSON File with Botkit

bot.js

const Botkit = require( 'botkit' );
const Q = require( 'q' );
const _ = require( 'lodash' );

var controller = Botkit.slackbot();

var bot = controller.spawn( {
  token: process.env.token
} ).startRTM( ( err, bot, payload ) => {
  loadHears()
  .then( ( hears ) => {
    if ( hears && _.isArray( hears ) ) {
      hears.forEach( ( h ) => {
        controller.hears( h.patterns, h.events, ( bot, message ) => {
          bot.reply( message, h.response );
        } );
      } );
    }
  } )
  .fail( ( err ) => {
    console.error( err );
  } );
} );

function loadHears() {
  var deferred = Q.defer();
  
  fs.readFile( 'hears.json', 'utf8', ( err, data ) => {
    if ( err ) {
      deferred.reject( err );
      
      return err;
    }
    
    deferred.resolve( JSON.parse( data ) );
  } );
  
  return deferred.promise;
}

hears.json

[
  {
    "patterns": [ "hi", "hello" ],
    "events": [ "ambient", "direct_message", "direct_mention" ],
    "response": "Hello!"
  },
  {
    "patterns": [ "help", "assistance" ],
    "events": [ "ambient", "direct_message", "direct_mention" ],
    "response": "For help, go to XYZ."
  }
]