hardhat.config.js

require("dotenv").config();

require('hardhat-contract-sizer');
require("@nomiclabs/hardhat-waffle");
require("solidity-coverage");
require('hardhat-gas-reporter');
require('hardhat-deploy');
require('hardhat-deploy-ethers');
require('@openzeppelin/hardhat-upgrades');
require('./tasks');

// This is a sample Hardhat task. To learn how to create your own go to
// https://hardhat.org/guides/create-task.html
task("accounts", "Prints the list of accounts", async (taskArgs, hre) => {
  const accounts = await hre.ethers.getSigners();

  for (const account of accounts) {
    console.log(account.address);
  }
});

function getMnemonic(networkName) {
  if (networkName) {
    const mnemonic = process.env['MNEMONIC_' + networkName.toUpperCase()]
    if (mnemonic && mnemonic !== '') {
      return mnemonic
    }
  }

  const mnemonic = process.env.MNEMONIC
  if (!mnemonic || mnemonic === '') {
    return 'test test test test test test test test test test test junk'
  }

  return mnemonic
}

function accounts(chainKey) {
  return { mnemonic: getMnemonic(chainKey) }
}

// You need to export an object to set up your config
// Go to https://hardhat.org/config/ to learn more

/**
 * @type import('hardhat/config').HardhatUserConfig
 */
module.exports = {

  solidity: {
    compilers: [
      {
        version: "0.8.17",
        settings: {
          optimizer: {
            enabled: true,
            runs: 200
          }
        }
      }    
    ]
  },
  contractSizer: {
    alphaSort: false,
    runOnCompile: true,
    disambiguatePaths: false,
  },

  namedAccounts: {
    deployer: {
      default: 0,    // wallet address 0, of the mnemonic in .env
    }
  },

  networks: {
    ethereum: {
      url: "https://mainnet.infura.io/v3/9aa3d95b3bc440fa88ea12eaa4456161",
      chainId: 1,
      accounts: accounts(),
    },
    arbitrum: {
      url: "https://arb1.arbitrum.io/rpc",
      chainId: 42161,
      accounts: accounts(),
    },
    optimism: {
      url: "https://mainnet.optimism.io",
      chainId: 10,
      accounts: accounts(),
    },

    "goerli-mainnet": {
      url: "https://goerli.infura.io/v3/9aa3d95b3bc440fa88ea12eaa4456161",
      chainId: 5,
      accounts: accounts(),
    }
  }
};