Truffle configuration example that shows how to import ES6 style modules.

truffle.js

require('babel-register') // should already exist in Truffle webpack box
require('babel-polyfill') // added to appease zeppelin-solidity
require('babel-node-modules')([ // added so that we can include zeppelin-solidity test JS
  'zeppelin-solidity' // module that has ES6 style files I wish to include
])

module.exports = {
  networks: {
    development: {
      host: '127.0.0.1',
      port: 8545,
      network_id: '*' // Match any network id
    }
  }
}