Código

• Crear carpeta decentralized-cupcakes
• Abrir editor de código en la carpeta
• Abrir consola
• Iniciar proyecto con hardhat

yarn add --dev hardhat

yarn hardhat init

• Elegir Create Javascript Project
• Reemplazamos el código del archivo hardhat.config.js por:

require('@nomicfoundation/hardhat-toolbox');

// NEVER record important private keys in your code - this is for demo purposes
const SEPOLIA_TESTNET_PRIVATE_KEY = '';
const ARBITRUM_MAINNET_TEMPORARY_PRIVATE_KEY = '';

/** @type import('hardhat/config').HardhatUserConfig */
module.exports = {
  solidity: '0.8.18',
  networks: {
    hardhat: {
      chainId: 1337,
    },
    arbitrumSepolia: {
      url: '<https://sepolia-rollup.arbitrum.io/rpc>',
      chainId: 421614,
      //accounts: [SEPOLIA_TESTNET_PRIVATE_KEY]
    },
    arbitrumOne: {
      url: '<https://arb1.arbitrum.io/rpc>',
      //accounts: [ARBITRUM_MAINNET_TEMPORARY_PRIVATE_KEY]
    },
  },
};

• ``Reemplazamos el código del contrato y renombramos el archivo Lock.sol por VendingMachine.sol

// SPDX-License-Identifier: UNLICENSED
pragma solidity ^0.8.9;

// Rule 2: The vending machine's rules can't be changed by anyone.
contract VendingMachine {
    // state variables = internal memory of the vending machine
    mapping(address => uint) private _cupcakeBalances;
    mapping(address => uint) private _cupcakeDistributionTimes;

    function giveCupcakeTo(address userAddress) public returns (bool) {
        // this code is unnecessary, but we're keeping it here so you can compare it to the JS implementation
        if (_cupcakeDistributionTimes[userAddress] == 0) {
            _cupcakeBalances[userAddress] = 0;
            _cupcakeDistributionTimes[userAddress] = 0;
        }

        // Rule 1: The vending machine will distribute a cupcake to anyone who hasn't recently received one.
        uint fiveSecondsFromLastDistribution = _cupcakeDistributionTimes[userAddress] + 5 seconds;
        bool userCanReceiveCupcake = fiveSecondsFromLastDistribution <= block.timestamp;
        if (userCanReceiveCupcake) {
            _cupcakeBalances[userAddress]++;
            _cupcakeDistributionTimes[userAddress] = block.timestamp;
            return true;
        } else {
            revert("HTTP 429: Too Many Cupcakes (you must wait at least 5 seconds between cupcakes)");
        }
    }

    // Getter function for the cupcake balance of a user
    function getCupcakeBalanceFor(address userAddress) public view returns (uint) {
        return _cupcakeBalances[userAddress];
    }
}

• Crear el archivo scripts/deploy.js

const hre = require('hardhat');

async function main() {
  const vendingMachine = await hre.ethers.deployContract('VendingMachine');
  await vendingMachine.waitForDeployment();
  console.log(`Cupcake vending machine deployed to ${vendingMachine.target}`);
}

main().catch((error) => {
  console.error(error);
  process.exit(1);
});

• Compilar proyecto 2 veces

yarn hardhat compile

Despliegue

• Necesitamos tener listos los fondos de prueba Sepolia ETH en la red Arbitrum Sepolia.
• Nos logueamos en Alchemy y creamos una nueva app, eligiendo a Arbitrum Sepolia como red
• Creada la app en el dashboard de alchemy, seleccionamos la url para el endpoint que nos genera y la ponemos el parametro url del campo arbitrumSepolia en el archivo da hardhat.config.js