evm-foundry

# Foundry Development for EVM Chains This skill covers Foundry setup and development for EVM-compatible chains with emphasis on Celo. ## When to Use - Setting up a new Foundry project - Writing and compiling Solidity smart contracts with forge - Testing contracts with forge test - Deploying contracts to Celo or other EVM chains - Verifying contracts on block explorers - Interacting with contracts using cast ## Foundry Tools | Tool | Purpose | |------|---------| | forge | Build, test, debug, deploy, and verify smart contracts | | cast | Interact with contracts and retrieve chain data from CLI | | anvil | Run a local Ethereum development node with forking support | | chisel | Fast Solidity REPL for interactive development | ## Installation ```bash # Install Foundryup (the Foundry installer) curl -L https://foundry.paradigm.xyz | bash # Install Foundry tools foundryup ``` For Windows, use Git BASH or WSL (Foundryup doesn't support PowerShell or Command Prompt). ## Quick Start ### Initialize Project ```bash forge init my-project cd my-project ``` ### Project Structure ``` my-project/ ├── foundry.toml # Configuration ├── src/ # Contract source files │ └── Counter.sol ├── test/ # Test files │ └── Counter.t.sol ├── script/ # Deployment scripts │ └── Counter.s.sol └── lib/ # Dependencies ``` ## Celo Network Information | Network | Chain ID | RPC Endpoint | |---------|----------|--------------| | Celo Mainnet | 42220 | https://forno.celo.org | | Celo Sepolia | 11142220 | https://forno.celo-sepolia.celo-testnet.org | ## Configuration ### foundry.toml for Celo ```toml [profile.default] src = "src" out = "out" libs = ["lib"] solc = "0.8.28" optimizer = true optimizer_runs = 200 [rpc_endpoints] celo = "https://forno.celo.org" celo_sepolia = "https://forno.celo-sepolia.celo-testnet.org" localhost = "http://127.0.0.1:8545" [etherscan] celo = { key = "${CELOSCAN_API_KEY}", chain = 42220, url = "https://api.celoscan.io/api" } celo_sepolia = { key = "${CELOSCAN_API_KEY}", chain = 11142220, url = "https://api.etherscan.io/v2/api" } ``` ### Environment Variables (.env) ```bash PRIVATE_KEY=your_private_key_here CELOSCAN_API_KEY=your_celoscan_api_key_here ``` Load environment variables: ```bash source .env ``` ## Writing Contracts ### Basic Contract ```solidity // src/MyContract.sol // SPDX-License-Identifier: MIT pragma solidity ^0.8.28; contract MyContract { string public name; address public owner; event NameChanged(string oldName, string newName); modifier onlyOwner() { require(msg.sender == owner, "Not owner"); _; } constructor(string memory _name) { name = _name; owner = msg.sender; } function setName(string memory _newName) external onlyOwner { string memory oldName = name; name = _newName; emit NameChanged(oldName, _newName); } } ``` ### Using OpenZeppelin ```bash forge install OpenZeppelin/openzeppelin-contracts ``` Add to `remappings.txt`: ``` @openzeppelin/contracts/=lib/openzeppelin-contracts/contracts/ ``` ```solidity // src/MyToken.sol // SPDX-License-Identifier: MIT pragma solidity ^0.8.28; import "@openzeppelin/contracts/token/ERC20/ERC20.sol"; import "@openzeppelin/contracts/access/Ownable.sol"; contract MyToken is ERC20, Ownable { constructor() ERC20("MyToken", "MTK") Ownable(msg.sender) { _mint(msg.sender, 1000000 * 10 ** decimals()); } function mint(address to, uint256 amount) external onlyOwner { _mint(to, amount); } } ``` ## Compilation ```bash # Compile all contracts forge build # Clean and rebuild forge clean && forge build # Check contract sizes forge build --sizes ``` ## Testing ### Test File Structure ```solidity // test/MyContract.t.sol // SPDX-License-Identifier: MIT pragma solidity ^0.8.28; import {Test, console} from "forge-std/Test.sol"; import {MyContract} from "../src/MyContract.sol"; contract MyContractTest is Test { MyContract public myContract; address public owner; address public user; function setUp() public { owner = address(this); user = makeAddr("user"); myContract = new MyContract("Initial Name"); } function test_InitialName() public view { assertEq(myContract.name(), "Initial Name"); } function test_Owner() public view { assertEq(myContract.owner(), owner); } function test_SetName() public { myContract.setName("New Name"); assertEq(myContract.name(), "New Name"); } function test_SetNameEmitsEvent() public { vm.expectEmit(true, true, true, true); emit MyContract.NameChanged("Initial Name", "New Name"); myContract.setName("New Name"); } function test_RevertWhen_NonOwnerSetsName() public { vm.prank(user); vm.expectRevert("Not owner"); myContract.setName("Hacked"); } function testFuzz_SetName(string memory newName) public { myContract.setName(newName); assertEq(myContract.name(), newName); } } ``` ### Running Tests ```bash # Run all tests forge test # Run with verbosity (show logs) forge test -vvv # Run specific test forge test --match-test test_SetName # Run specific contract forge test --match-contract MyContractTest # Run with gas reporting forge test --gas-report # Run with coverage forge coverage # Fork testing against Celo mainnet forge test --fork-url https://forno.celo.org ``` ## Deployment ### Deployment Script ```solidity // script/Deploy.s.sol // SPDX-License-Identifier: MIT pragma solidity ^0.8.28; import {Script, console} from "forge-std/Script.sol"; import {MyContract} from "../src/MyContract.sol"; contract DeployScript is Script { function setUp() public {} function run() public { uint256 deployerPrivateKey = vm.envUint("PRIVATE_KEY"); vm.startBroadcast(deployerPrivateKey); MyContract myContract = new MyContract("My Contract Name"); console.log("Contract deployed to:", address(myContract)); vm.stopBroadcast(); } } ``` ### Deploy Commands ```bash # Deploy to local Anvil forge script script/Deploy.s.sol --rpc-url http://127.0.0.1:8545 --broadcast # Deploy to Celo Sepolia forge script script/Deploy.s.sol --rpc-url https://forno.celo-sepolia.celo-testnet.org --broadcast --private-key $PRIVATE_KEY # Deploy to Celo Mainnet forge script script/Deploy.s.sol --rpc-url https://forno.celo.org --broadcast --private-key $PRIVATE_KEY # Deploy with verification forge script script/Deploy.s.sol --rpc-url https://forno.celo-sepolia.celo-testnet.org --broadcast --verify --private-key $PRIVATE_KEY ``` ### Quick Deploy with forge create ```bash # Deploy to Celo Sepolia forge create src/MyContract.sol:MyContract \ --rpc-url https://forno.celo-sepolia.celo-testnet.org \ --private-key $PRIVATE_KEY \ --constructor-args "My Contract Name" # Deploy with verification forge create src/MyContract.sol:MyContract \ --rpc-url https://forno.celo-sepolia.celo-testnet.org \ --private-key $PRIVATE_KEY \ --constructor-args "My Contract Name" \ --verify \ --etherscan-api-key $CELOSCAN_API_KEY ``` ## Verification ### Verify Existing Contract ```bash # Verify on Celo Sepolia forge verify-contract \ --chain-id 11142220 \ <CONTRACT_ADDRESS> \ src/MyContract.sol:MyContract \ --etherscan-api-key $CELOSCAN_API_KEY \ --watch # Verify on Celo Mainnet forge verify-contract \ --chain-id 42220 \ <CONTRACT_ADDRESS> \ src/MyContract.sol:MyContract \ --etherscan-api-key $CELOSCAN_API_KEY \ --watch # With constructor arguments forge verify-contract \ --chain-id 11142220 \ <CONTRACT_ADDRESS> \ src/MyContract.sol:MyContract \ --etherscan-api-key $CELOSCAN_API_KEY \ --constructor-args $(cast abi-encode "constructor(string)" "My Contract Name") \ --watch ``` ## Cast Commands ### Reading Data ```bash # Get balance cast balance <ADDRESS> --rpc-url https://forno.celo.org # Call view function cast call <CONTRACT_ADDRESS> "name()(string)" --rpc-url https://forno.celo.org # Get storage slot cast storage <CONTRACT_ADDRESS> 0 --rpc-url https://forno.celo.org # Get block number cast block-number --rpc-url https://forno.celo.org ``` ### Writing Data ```bash # Send transaction cast send <CONTRACT_ADDRESS> "setName(string)" "New Name" \ --rpc-url https://forno.celo.org \ --private-key $PRIVATE_KEY # Transfer CELO cast send <TO_ADDRESS> --value 1ether \ --rpc-url https://forno.celo.org \ --private-key $PRIVATE_KEY ``` ### Utility Commands ```bash # Encode function call cast calldata "setName(string)" "New Name" # Decode function call cast 4byte-decode <CALLDATA> # Convert units cast to-wei 1 ether cast from-wei 1000000000000000000 # Get ABI-encoded constructor args cast abi-encode "constructor(string)" "My Contract Name" ``` ## Anvil (Local Node) ```bash # Start local node anvil # Start with fork of Celo mainnet anvil --fork-url https://forno.celo.org # Start with specific block anvil --fork-url https://forno.celo.org --fork-block-number 12345678 ``` ## Block Explorers - **Celo Mainnet:** https://celoscan.io - **Celo Sepolia:** https://sepolia.celoscan.io ## Additional Resources - [foundry-config.md](references/foundry-config.md) - Detailed configuration options - [testing-patterns.md](references/testing-patterns.md) - Advanced testing patterns - [security-checklist.md](rules/security-checklist.md) - Security best practices