truffle-config.js

require('babel-register');
require('babel-polyfill');
require('dotenv').config();
// const HDWalletProvider =  require('truffle-hdwallet-provider-privkey');
const privateKeys = process.env.PRIVATE_KEYS || ""

module.exports = {
    networks: {
        development: {
            host: "127.0.0.1",
            port: 7545,
            network_id: "*" // Match any network id
        },
        // ropsten: {
        //   provider: function() {
        //     return new HDWalletProvider(
        //       privateKeys.split(','), // Array of account private keys
        //       `https://ropsten.infura.io/v3/${process.env.INFURA_API_KEY}`// Url to an Ethereum Node
        //     )
        //   },
        //   gas: 5000000,
        //   gasPrice: 25000000000,
        //   network_id: 3
        // }
    },
    contracts_directory: './src/contracts/',
    contracts_build_directory: './src/abis/',
    compilers: {
        solc: {
            optimizer: {
                enabled: true,
                runs: 200
            }
        }
    }
}