Deploy a smart contract to an arbitrary address

This is one of the beauties of foundry framework, the ability to deploy a smart contract on any address. web3 developers gain alot from this because it aids you in experimenting with address with smart contract without having to go through hassle of getting an address deployed on the testnet or mainnet with code.

getCode

Signature

function getCode(string calldata) external returns (bytes memory);

Description

Returns the creation bytecode for a contract in the project given the path to the contract.

The calldata parameter can either be in the form ContractFile.sol (if the filename and contract name are the same),ContractFile.sol:ContractName, or the path to an artifact, relative to the root of your project.

ℹ️ Note

getCode requires read permission for the output directory, see file cheatcodes.

To grant read access set fs_permissions = [{ access = "read", path = "./out"}] in your foundry.toml.

Examples

MyContract myContract = new MyContract(arg1, arg2);

// Let's do the same thing with `getCode`
bytes memory args = abi.encode(arg1, arg2);
bytes memory bytecode = abi.encodePacked(vm.getCode("MyContract.sol:MyContract"), args);
address anotherAddress;
assembly {
    anotherAddress := create(0, add(bytecode, 0x20), mload(bytecode))
}

assertEq0(address(myContract).code, anotherAddress.code); // [PASS]

Deploy a contract to an arbitrary address by combining getCode and etch

// Deploy

bytes memory args = abi.encode(arg1, arg2);
bytes memory bytecode = abi.encodePacked(vm.getCode("MyContract.sol:MyContract"), args);
address deployed;
assembly {
deployed := create(0, add(bytecode, 0x20), mload(bytecode))
}

// Set the bytecode of an arbitrary address
vm.etch(targetAddr, deployed.code);

for more info check https://book.getfoundry.sh/cheatcodes/get-code?highlight=etch#examples