forge-scripting

# Forge Script Deployment Patterns ## Basic Deployment Script ```solidity // SPDX-License-Identifier: MIT pragma solidity ^0.8.20; import {Script, console2} from "forge-std/Script.sol"; import {MyToken} from "../src/MyToken.sol"; contract DeployScript is Script { function run() external { uint256 deployerKey = vm.envUint("DEPLOYER_PRIVATE_KEY"); address deployer = vm.addr(deployerKey); console2.log("Deployer:", deployer); console2.log("Balance:", deployer.balance); vm.startBroadcast(deployerKey); MyToken token = new MyToken("My Token", "MTK", 1_000_000e18); console2.log("Token deployed at:", address(token)); vm.stopBroadcast(); } } ``` ## Running Scripts ```bash # Dry run (simulation only, no tx sent) forge script script/Deploy.s.sol --rpc-url $ETH_RPC_URL # Broadcast (send real transactions) forge script script/Deploy.s.sol --rpc-url $ETH_RPC_URL --broadcast # Broadcast + verify on Etherscan forge script script/Deploy.s.sol --rpc-url $ETH_RPC_URL \ --broadcast --verify --etherscan-api-key $ETHERSCAN_API_KEY # With specific sender forge script script/Deploy.s.sol --rpc-url $ETH_RPC_URL \ --broadcast --sender 0xDeployer # Resume failed broadcast forge script script/Deploy.s.sol --rpc-url $ETH_RPC_URL --resume # Slow mode (wait for each tx confirmation) forge script script/Deploy.s.sol --rpc-url $ETH_RPC_URL --broadcast --slow ``` ## Deployment Script Template ```solidity // SPDX-License-Identifier: MIT pragma solidity ^0.8.20; import {Script, console2} from "forge-std/Script.sol"; import {ERC1967Proxy} from "@openzeppelin/contracts/proxy/ERC1967/ERC1967Proxy.sol"; import {MyProtocol} from "../src/MyProtocol.sol"; import {Treasury} from "../src/Treasury.sol"; contract DeployProtocol is Script { struct DeployConfig { address admin; address treasury; uint256 feeRate; address weth; } function getConfig() internal view returns (DeployConfig memory) { if (block.chainid == 1) { return DeployConfig({ admin: vm.envAddress("MAINNET_ADMIN"), treasury: vm.envAddress("MAINNET_TREASURY"), feeRate: 30, // 0.3% weth: 0xC02aaA39b223FE8D0A0e5C4F27eAD9083C756Cc2 }); } else if (block.chainid == 8453) { return DeployConfig({ admin: vm.envAddress("BASE_ADMIN"), treasury: vm.envAddress("BASE_TREASURY"), feeRate: 30, weth: 0x4200000000000000000000000000000000000006 }); } else if (block.chainid == 11155111) { return DeployConfig({ admin: msg.sender, treasury: msg.sender, feeRate: 100, weth: address(0) }); } else { revert("Unsupported chain"); } } function run() external { DeployConfig memory cfg = getConfig(); uint256 deployerKey = vm.envUint("DEPLOYER_PRIVATE_KEY"); vm.startBroadcast(deployerKey); // Deploy implementation MyProtocol impl = new MyProtocol(); console2.log("Implementation:", address(impl)); // Deploy proxy bytes memory initData = abi.encodeCall( MyProtocol.initialize, (cfg.admin, cfg.treasury, cfg.feeRate, cfg.weth) ); ERC1967Proxy proxy = new ERC1967Proxy(address(impl), initData); console2.log("Proxy:", address(proxy)); // Deploy treasury Treasury treasury = new Treasury(address(proxy)); console2.log("Treasury:", address(treasury)); // Post-deploy configuration MyProtocol(address(proxy)).setTreasury(address(treasury)); vm.stopBroadcast(); // Verify deployment (runs after broadcast) _verify(address(proxy), cfg); } function _verify(address proxy, DeployConfig memory cfg) internal view { MyProtocol protocol = MyProtocol(proxy); require(protocol.admin() == cfg.admin, "Admin mismatch"); require(protocol.feeRate() == cfg.feeRate, "Fee mismatch"); console2.log("Verification passed"); } } ``` ## Multi-Chain Deployment ```solidity contract MultiChainDeploy is Script { function deployToChain(string memory rpcAlias) internal { vm.createSelectFork(rpcAlias); uint256 deployerKey = vm.envUint("DEPLOYER_PRIVATE_KEY"); vm.startBroadcast(deployerKey); MyContract c = new MyContract(); console2.log("Chain", block.chainid, "deployed at:", address(c)); vm.stopBroadcast(); } function run() external { deployToChain("mainnet"); deployToChain("base"); deployToChain("optimism"); } } ``` ```bash # Deploy to multiple chains forge script script/MultiChainDeploy.s.sol --broadcast \ --multi --verify --etherscan-api-key $ETHERSCAN_API_KEY ``` ## Cheatcodes in Scripts ```solidity // Environment variables uint256 key = vm.envUint("PRIVATE_KEY"); address addr = vm.envAddress("ADMIN_ADDRESS"); string memory rpc = vm.envString("RPC_URL"); bool isProd = vm.envBool("IS_PRODUCTION"); uint256 optionalVal = vm.envOr("OPTIONAL_VAL", uint256(42)); // Broadcasting vm.startBroadcast(key); // All subsequent calls are real txs vm.stopBroadcast(); vm.broadcast(key); // Only next call is a real tx // File I/O string memory json = vm.readFile("config.json"); vm.writeFile("output.json", data); // JSON parsing bytes memory raw = vm.parseJson(json, ".deploy.address"); address deployed = abi.decode(raw, (address)); // Compute CREATE2 address address predicted = vm.computeCreate2Address( salt, keccak256(type(MyContract).creationCode), factory ); ``` ## Broadcast Artifacts After `--broadcast`, Foundry saves transaction data to: ``` broadcast/ └── Deploy.s.sol/ ├── 1/ # Chain ID │ ├── run-latest.json # Latest broadcast │ └── run-1234567.json # Timestamped └── 8453/ └── run-latest.json ``` Each file contains: - Transaction hashes - Contract addresses - Gas used - Constructor arguments ## Verification in Scripts ```bash # Auto-verify during broadcast forge script script/Deploy.s.sol --broadcast --verify \ --etherscan-api-key $ETHERSCAN_API_KEY # Verify after deployment forge verify-contract 0xContractAddress MyContract \ --chain-id 1 --etherscan-api-key $ETHERSCAN_API_KEY \ --constructor-args $(cast abi-encode "constructor(address,uint256)" 0xAdmin 100) ``` ## Script Best Practices 1. **Always dry-run first**: Run without `--broadcast` to simulate 2. **Pin dependencies**: Use exact compiler and dependency versions 3. **Chain-specific config**: Use `block.chainid` for per-chain settings 4. **Post-deploy verification**: Assert critical state after deployment 5. **Idempotent scripts**: Check if contracts exist before deploying 6. **Save addresses**: Write deployed addresses to a registry file 7. **Use `--slow` for mainnet**: Wait for confirmations on high-value deploys ```solidity // Idempotent deploy pattern function run() external { address existing = vm.envOr("EXISTING_CONTRACT", address(0)); if (existing != address(0) && existing.code.length > 0) { console2.log("Already deployed at:", existing); return; } // ... deploy } ``` ## Gas Estimation ```bash # Estimate gas without broadcasting forge script script/Deploy.s.sol --rpc-url $ETH_RPC_URL -vvvv # The -vvvv output shows gas used per transaction ```