node -v && npm -v

npx truffle unbox optimism-bridge <DIRECTORY_NAME>

npm install -g truffle
truffle unbox optimism-bridge <DIRECTORY_NAME>

cd truffle-bridge-demo

GOERLI_MNEMONIC="<your-wallet-mnemonic>"
INFURA_KEY="<your-infura-key>"

//SPDX-License-Identifier: Unlicense
// This contract runs on L1, and controls a Greeter on L2.
pragma solidity ^0.8.0;
import { ICrossDomainMessenger } from
    "@eth-optimism/contracts/libraries/bridge/ICrossDomainMessenger.sol";
contract GreeterL1 {
    address crossDomainMessengerAddr = 0x5086d1eEF304eb5284A0f6720f79403b4e9bE294;
    address greeterL2Addr = 0xC0836cCc8FBa87637e782Dde6e6572aD624fb984;
    function setGreeting(string calldata _greeting) public {
        bytes memory message;
        message = abi.encodeWithSignature("setGreeting(string)",
            _greeting);
        ICrossDomainMessenger(crossDomainMessengerAddr).sendMessage(
            greeterL2Addr,
            message,
            1000000   // within the free gas limit amount
        );
    }      // function setGreeting
}          // contract GreeterL1

var Greeter = artifacts.require("GreeterL1");
/**
 * Set L2 Greeting
 * Run this migration on L1 to update the L1 greeting.
 */
module.exports = async function (deployer) {
  console.log("Updating the L2 Greetings contract from L1!");
  const instance = await Greeter.deployed();
  const tx = await instance.setGreeting("Greetings from Truffle!");
  console.log(`Greeter txn confirmed on L1! ${tx.receipt.transactionHash}`);
  console.log(`Bridging message to L2 Greeter contract...`);
  console.log(
    `In about 1 minute, check the Greeter contract "read" function: https://goerli-optimism.etherscan.io/address/0xC0836cCc8FBa87637e782Dde6e6572aD624fb984#readContract`
  );
};

/SPDX-License-Identifier: Unlicense
// This contract runs on L2, and controls a Greeter on L1.
pragma solidity ^0.8.0;
import { ICrossDomainMessenger } from
    "@eth-optimism/contracts/libraries/bridge/ICrossDomainMessenger.sol";
contract GreeterL2 {
    address crossDomainMessengerAddr = 0x4200000000000000000000000000000000000007;
    address greeterL1Addr = 0x7fA4D972bB15B71358da2D937E4A830A9084cf2e;
    function setGreeting(string calldata _greeting) public {
        bytes memory message;
        message = abi.encodeWithSignature("setGreeting(string)",
            _greeting);
        ICrossDomainMessenger(crossDomainMessengerAddr).sendMessage(
            greeterL1Addr,
            message,
            1000000   // irrelevant here
        );
    }      // function setGreeting
}          // contract GreeterL2

require("dotenv").config();
const sdk = require("@eth-optimism/sdk");
const ethers = require("ethers");
const Greeter = artifacts.require("GreeterL2");
const goerliMnemonic = process.env["GOERLI_MNEMONIC"];
const infuraKey = process.env["INFURA_KEY"];
const sleep = (milliseconds) => {
  return new Promise((resolve) => setTimeout(resolve, milliseconds));
};
/**
 * Set L1 Greeting
 * Run this migration on L1 to update the L1 greeting.
 */
module.exports = async function (deployer) {
  const newGreeting = "Greetings from Truffle!"; //<---- CHANGE THIS VALUE TO YOUR NAME!!!
  const instance = await Greeter.deployed();
  console.log("Updating the L1 Greetings contract from L2!");
  const tx = await instance.setGreeting(newGreeting);
  const txHash = tx.receipt.transactionHash;
  console.log(`Greeter txn confirmed on L2! ${txHash}`);
  console.log(
    `Bridging message to L1 Greeter contract.\n This will take at least 1-5 min...`
  );
  // Set providers for Optimism sdk
  const l1Provider = new ethers.providers.JsonRpcProvider(
    "https://goerli.infura.io/v3/" + infuraKey
  );
  const l2Provider = new ethers.providers.JsonRpcProvider(
    "https://optimism-goerli.infura.io/v3/" + infuraKey
  );
  // Connect an L1 signer
  const wallet = ethers.Wallet.fromMnemonic(goerliMnemonic);
  const l1Signer = wallet.connect(l1Provider);
  // Initialize sdk messenger
  const crossChainMessenger = new sdk.CrossChainMessenger({
    l1ChainId: 5,
    l2ChainId: 420,
    l1SignerOrProvider: l1Signer,
    l2SignerOrProvider: l2Provider,
  });
  let statusReady = false;
  // Sleep for 1 min during L2 -> L1 bridging
  await sleep(60000); // 60 seconds
  // Poll the L1 msg status
  while (!statusReady) {
    let status = null;
    status = await crossChainMessenger.getMessageStatus(txHash);
    statusReady = status == sdk.MessageStatus.READY_FOR_RELAY;
    if (!statusReady) {
      console.log(
        "Message not yet received on L1.\n Retrying in 10 seconds..."
      );
      await sleep(10000); // 10 seconds
    }
  }
  console.log("Message received! Finalizing...");
  // Open the message on L1
  finalize = await crossChainMessenger.finalizeMessage(txHash);
  console.log(
    `Message finalized. Check the L1 Greeter contract "read" function: https://goerli.etherscan.io/address/0x7fA4D972bB15B71358da2D937E4A830A9084cf2e#readContract`
  );
};

npm run deploy