truffle-config.js

/**
 * @dev You must create a `.env` file by following `.env.example`.
 * @param {string} network The name of the testnet
 */
function createProvider(network) {
    if (process.env.CI) {
        return {};
    }

    require("dotenv").config();
    const HDWalletProvider = require("@truffle/hdwallet-provider");

    if (!process.env.MNEMONIC) {
        console.log("Please set your MNEMONIC in a .env file");
        process.exit(1);
    }
    if (!process.env.INFURA_API_KEY) {
        console.log("Please set your INFURA_API_KEY");
        process.exit(1);
    }
    return () => {
        return new HDWalletProvider(process.env.MNEMONIC, `https://${network}.infura.io/v3/` + process.env.INFURA_API_KEY);
    };
}

module.exports = {
    compilers: {
        solc: {
            version: "0.5.16",
            settings: {
                optimizer: {
                    enabled: true,
                    runs: 200,
                },
            },
        },
    },
    mocha: {
        bail: true,
        enableTimeouts: false,
    },
    networks: {
        development: {
            host: "127.0.0.1",
            gas: "6000000",
            network_id: "*",
            port: "8545",
            skipDryRun: true,
        },
        kovan: {
            provider: createProvider("kovan"),
            gas: "6000000",
            network_id: "42",
            skipDryRun: true,
        },
        rinkeby: {
            provider: createProvider("rinkeby"),
            gas: "6000000",
            network_id: "4",
            skipDryRun: true,
        },
        ropsten: {
            provider: createProvider("ropsten"),
            gas: "6000000",
            network_id: "3",
            skipDryRun: true,
        },
        mainnet: {
            provider: createProvider("mainnet"),
            gas: "6000000",
            network_id: "1",
        },
    },
    plugins: ["solidity-coverage"],
};