truffle-config.js

// require('ts-node').register({ files: true })

// require('babel-register')
require('babel-polyfill')
require('dotenv').config()

const HDWalletProvider = require('@truffle/hdwallet-provider')
const privateKeys = process.env.PRIVATE_KEYS || ''

module.exports = {
    networks: {
        development: {
            host: '127.0.0.1',
            port: 7545,
            network_id: '*', // Match any network id
        },
        kovan: {
            provider: function () {
                return new HDWalletProvider(
                    privateKeys.split(','), // Array of account private keys
                    `https://kovan.infura.io/v3/${process.env.INFURA_ID}` // Url to an Ethereum Node
                )
            },
            gas: 5000000,
            gasPrice: 5000000000, // 5 gwei
            network_id: 42,
            skipDryRun: true,
        },
        rinkeby: {
            provider: function () {
                return new HDWalletProvider(
                    privateKeys.split(','), // Array of account private keys
                    `https://rinkeby.infura.io/v3/${process.env.INFURA_ID}` // Url to an Ethereum Node
                )
            },
            gas: 5000000,
            gasPrice: 5000000000, // 5 gwei
            network_id: 4,
            skipDryRun: true,
        },
        ropsten: {
            provider: function () {
                return new HDWalletProvider(
                    privateKeys.split(','), // Array of account private keys
                    `https://ropsten.infura.io/v3/${process.env.INFURA_ID}` // Url to an Ethereum Node
                )
            },
            gas: 5000000,
            gasPrice: 5000000000, // 5 gwei
            network_id: 3,
            skipDryRun: true,
        },
        main: {
            provider: function () {
                return new HDWalletProvider(
                    privateKeys.split(','), // Array of account private keys
                    `https://main.infura.io/v3/${process.env.INFURA_ID}` // Url to an Ethereum Node
                )
            },
            gas: 5000000,
            gasPrice: 5000000000, // 5 gwei
            network_id: 1,
        },
    },
    contracts_directory: './ethereum/src/contracts/',
    contracts_build_directory: './ethereum/build/',
    migrations_directory: './ethereum/migrations/',
    compilers: {
        solc: {
            version: '>=0.6.0 <0.8.0',
            optimizer: {
                enabled: true,
                runs: 200,
            },
        },
    },
}