Foundry x Huff

A foundry library for working with huff contracts. Take a look at our project template to see an example project that uses this library.

Installing

First, install the huff compiler by running:

curl -L get.huff.sh | bash

Then, install this library with forge:

forge install huff-language/foundry-huff

Usage

The HuffDeployer is a Solidity library that takes a filename and deploys the corresponding Huff contract, returning the address that the bytecode was deployed to. To use it, simply import it into your file by doing:

import {HuffDeployer} from "foundry-huff/HuffDeployer.sol";

To compile contracts, you can use HuffDeployer.deploy(string fileName), which takes in a single string representing the filename's path relative to the src directory. Note that the file ending, i.e. .huff, must be omitted. Here is an example deployment (where the contract is located in src/test/contracts/Number.huff):

// SPDX-License-Identifier: Apache-2.0
pragma solidity >=0.7.0 <0.9.0;

import {HuffDeployer} from "foundry-huff/HuffDeployer";

interface Number {
  function setNumber(uint256) external;
  function getNumber() external returns (uint256);
}

contract HuffDeployerExample {
  function deploy() public {
    // Deploy a new instance of src/test/contracts/Number.huff
    address addr = HuffDeployer.deploy("test/contracts/Number");

    // To call a function on the deployed contract, create an interface and wrap the address like so
    Number number = Number(addr);
  }
}

To deploy a Huff contract with constructor arguments, you can chain commands onto the HuffDeployer.

For example, to deploy the contract src/test/contracts/Constructor.huff with arguments (uint256(0x420), uint256(0x420)), you are encouraged to follow the logic defined in the deploy function of the HuffDeployerArguments contract below.

// SPDX-License-Identifier: Apache-2.0
pragma solidity >=0.7.0 <0.9.0;

import {HuffDeployer} from "foundry-huff/HuffDeployer";

interface Constructor {
  function getArgOne() external returns (address);
  function getArgTwo() external returns (uint256);
}

contract HuffDeployerArguments {
  function deploy() public {
    // Deploy the contract with arguments
    address addr = HuffDeployer
      .config()
      .with_args(bytes.concat(abi.encode(uint256(0x420)), abi.encode(uint256(0x420))))
      .deploy("test/contracts/Constructor");

    // To call a function on the deployed contract, create an interface and wrap the address
    Constructor construct = Constructor(addr);

    // Validate we deployed the Constructor with the correct arguments
    assert(construct.getArgOne() == address(0x420));
    assert(construct.getArgTwo() == uint256(0x420));
  }

  function depreciated_deploy() public {
    address addr = HuffDeployer.deploy_with_args(
      "test/contracts/Constructor",
      bytes.concat(abi.encode(uint256(0x420)), abi.encode(uint256(0x420)))
    );

    // ...
  }
}

HuffDeployer also enables you to instantiate contracts, from the test file, even if they have no constructor macro!

This is possible by using Foundry's ffi cheatcode.

NOTE: It is highly recommended that you read the foundry book, or at least familiarize yourself with foundry, before using this library to avoid easily susceptible footguns.

Let's use the huff contract src/test/contracts/NoConstructor.huff, which has no defined constructor macro. The inline-instantiation defined in the deploy function of the HuffDeployerCode contract below is recommended.

// SPDX-License-Identifier: Apache-2.0
pragma solidity >=0.7.0 <0.9.0;

import {HuffDeployer} from "foundry-huff/HuffDeployer";

interface Constructor {
  function getArgOne() external returns (address);
  function getArgTwo() external returns (uint256);
}

contract HuffDeployerCode {

  function deploy() public {
    // Define a new constructor macro as a string
    string memory constructor_macro = "#define macro CONSTRUCTOR() = takes(0) returns (0) {"
      "    // Copy the first argument into memory \n"
      "    0x20                        // [size] - byte size to copy \n"
      "    0x40 codesize sub           // [offset, size] - offset in the code to copy from\n "
      "    0x00                        // [mem, offset, size] - offset in memory to copy to \n"
      "    codecopy                    // [] \n"
      "    // Store the first argument in storage\n"
      "    0x00 mload                  // [arg] \n"
      "    [CONSTRUCTOR_ARG_ONE]       // [CONSTRUCTOR_ARG_ONE, arg] \n"
      "    sstore                      // [] \n"
      "    // Copy the second argument into memory \n"
      "    0x20                        // [size] - byte size to copy \n"
      "    0x20 codesize sub           // [offset, size] - offset in the code to copy from \n"
      "    0x00                        // [mem, offset, size] - offset in memory to copy to \n"
      "    codecopy                    // [] \n"
      "    // Store the second argument in storage \n"
      "    0x00 mload                  // [arg] \n"
      "    [CONSTRUCTOR_ARG_TWO]       // [CONSTRUCTOR_ARG_TWO, arg] \n"
      "    sstore                      // [] \n"
      "}";

    // Deploy the contract with arguments
    address addr = HuffDeployer
      .config()
      .with_args(bytes.concat(abi.encode(uint256(0x420)), abi.encode(uint256(0x420))))
      .with_code(constructor_macro)
      .deploy("test/contracts/NoConstructor");

    // To call a function on the deployed contract, create an interface and wrap the address
    Constructor construct = Constructor(addr);

    // Validate we deployed the Constructor with the correct arguments
    assert(construct.getArgOne() == address(0x420));
    assert(construct.getArgTwo() == uint256(0x420));
  }

  function depreciated_deploy_with_code() public {
    address addr = HuffDeployer.deploy_with_code(
      "test/contracts/Constructor",
      constructor_macro
    );

    // ...
  }
}