_Follow along with the video_ --- To deploy the `BagelToken` and `MerkleAirdrop` contracts, we can follow a structured approach by creating a **deployment script**. ### `deployMerkleAirdrop` Function Inside the `script` directory, we can start coding the deployment contract by importing the required libraries: ```js // SPDX-License-Identifier: MIT pragma solidity ^0.8.24; import {MerkleAirdrop} from "src/MerkleAirdrop.sol"; import {BagelToken} from "src/BagelToken.sol"; import {Script} from "forge-std/Script.sol"; import {IERC20} from "@openzeppelin/contracts/token/ERC20/IERC20.sol"; ``` Next, create the deployment function to deploy the contracts, mint tokens, and transfer them to the airdrop contract: ```js function deployMerkleAirdrop() public returns (MerkleAirdrop, BagelToken) { vm.startBroadcast(); BagelToken bagelToken = new BagelToken(); MerkleAirdrop airdrop = new MerkleAirdrop(ROOT, IERC20(bagelToken)); bagelToken.mint(bagelToken.owner(), AMOUNT_TO_TRANSFER); // amount for four claimers IERC20(bagelToken).transfer(address(airdrop), AMOUNT_TO_TRANSFER); // transfer tokens to the airdrop contract vm.stopBroadcast(); return (airdrop, bagelToken); } ``` ### Test Environment Setup To retrieve and use the last deployed contract in our `MerkleAirdrop.t.sol` file, install `foundry-devops` with the command: ```bash forge install cyfrin/foundry-devops --no-commit ``` Then, in the `setUp` function, add a check to determine if the current chain is ZKsync: ```js //.. import {ZkSyncChainChecker} from "foundry-devops/src/ZkSyncChainChecker.sol"; function setUp() public { if (!isZkSyncChain()) { //chain verification DeployMerkleAirdrop deployer = new DeployMerkleAirdrop(); (airdrop, token) = deployer.deployMerkleAirdrop(); } else { token = new BagelToken(); airdrop = new MerkleAirdrop(merkleRoot, token); token.mint(token.owner(), amountToSend); token.transfer(address(airdrop), amountToSend); } (user, userPrivKey) = makeAddrAndKey("user"); } ``` The `zkSyncChainChecker` determines if we are currently on a ZKsync chain. If we are not, we deploy the contracts using our script and proceed with testing. Otherwise, we directly deploy new instances of the `BagelToken` and `MerkleAirdrop` contracts, mint the necessary tokens to the contract owner, and transfer the required amount of tokens to the `MerkleAirdrop` contract.