LZ Kit

This package was created with the aim of boosting productivity for developers who are building innovative projects on LayerZero.

Getting Started

Prerequisites

Hardhat

LZ Kit was designed for a hardhat project so if you didn't setup hardhat, follow this tutorial first.

Hardhat Deploy

You also need to install hardhat-deploy plugin to run lz-kit test. Follow this link for details.

Install

npm install -g @lz-kit/cli

yarn global add @lz-kit/cli

You need to import @lz-kit/cli/hardhat in your hardhat.config.js or hardhat.config.ts:

import "@lz-kit/cli/hardhat";

require("@lz-kit/cli/hardhat");

Usage

Write a cross chain contract e.g. MyLzApp:

// contracts/MyLzApp.sol

pragma solidity ^0.8.0;

import "@layerzerolabs/solidity-examples/contracts/lzApp/LzApp.sol";

contract MyLzApp {
  constructor(address _lzEndpoint) LzApp(_lzEndpoint) {}

  // ... send and receive functions
}

Write a deployment script to deploy MyLzApp:

// deploy/00_MyLzApp.ts

import { constants } from "ethers";
import { endpoint } from "../constants/layerzero.json";

export default async ({ getNamedAccounts, deployments, network }) => {
  const { deploy } = deployments;
  const { deployer } = await getNamedAccounts();

  await deploy("MyLzApp", {
    from: deployer,
    args: [endpoint[network.name]],
    log: true,
  });
};

Write a sample test script:

// test/MyLzApp.test.ts

import { utils } from "ethers";
import { getChain } from "hardhat";
import { getChainId } from "./ethers";

describe("MyLzApp", function () {
  it("should test", async function () {
    const ethereum = await getChain("ethereum-fork");
    const arbitrum = await getChain("arbitrum-fork");
    const optimism = await getChain("optimism-fork");

    // your testing code
  });
});

Set environment variables for reuse:

INFURA_API_KEY=<your infura api key>
MNEMONIC=<your seed phrase>

Bootstrap ethereum, optimism and arbitrum in the background (fork networks and spin up relayers between them):

lz-kit bootstrap -k "$INFURA_API_KEY" --mnemonic "$MNEMONIC" --balance 10000 --accounts 3 ethereum optimism arbitrum &

Deploy contracts, configure trusted remotes and run tests:

lz-kit test -s ethereum-fork -d arbitrum-fork --mnemonic "$MNEMONIC" --deploy --config MyLzApp

or you can break it down into two steps:

lz-kit deploy --networks ethereum-fork arbitrum-fork --mnemonic "$MNEMONIC" --config MyLzApp &&
lz-kit test --networks ethereum-fork arbitrum-fork --mnemonic "$MNEMONIC"

Reference

lz-kit fork

It runs a hardhat node that forks a network at http://127.0.0.1:<port>. Default port is 8000 + (e.g. ethereum-fork: 8001, arbitrum-fork: 50161) but you can specify option port to override it.

An example to fork ethereum and arbitrum:

lz-kit fork ethereum -k "$INFURA_API_KEY" &&
lz-kit fork optimism -k "$INFURA_API_KEY" &&
lz-kit fork arbitrum -k "$INFURA_API_KEY"

After forking, you'll see new config files under hardhat-configs/. We recommend you to add below to your .gitignore:

hardhat-configs/

As long as you keep those config files under hardhat-configs/, you have three additional hardhat networks ethereum-fork, optimism-fork and arbitrum-fork that you can use for testing, even if you didn't specify in your hardhat.config.js or hardhat.config.ts.

lz-kit relayer

It runs a relayer that read events from <source network> and calls lzReceive() of UA contracts on the destination networks.

An example to run relayers on three forked networks in the background:

lz-kit relayer ethereum-fork --dest arbitrum-fork optimism-fork &
lz-kit relayer optimism-fork --dest ethereum-fork arbitrum-fork &
lz-kit relayer arbitrum-fork --dest ethereum-fork optimism-fork &

Option --dest needs to be placed at the end of the command because it accepts variable number of networks.

lz-bootstrap

It first lz-kit fork networks, lz-kit relayer for them and sets balance for the first account of each network if needed.

An example to bootstrap all networks, set balance of three accounts of each network to 10000 ETH:

lz-kit bootstrap -k "$INFURA_API_KEY" --mnemonic "$MNEMONIC" --balance 10000 --accounts 3 ethereum optimism arbitrum

Network names need to be placed at the end of the command because it accepts variable number of networks.

lz-kit config

It sets trusted remotes for all combinations for given networks. The target contract must be a subclass of LzApp.

An example to config all forked networks:

lz-kit config --mnemonic "$MNEMONIC" ethereum-fork optimism-fork arbitrum-fork

Option --mnemonic specifies which account to be used when calling setTrustedRemoteAddress().

lz-kit test

It deploys and configures contracts if needed and run hardhat test with additional HRE objects srcChain and destChain.

It has dependency on hardhat-deploy plugin. Also you need to import @lz-kit/cli/hardhat in your hardhat.config.js or hardhat.config.js.

An example to test cross chain contract on all combinations of forked networks:

lz-kit test --networks ethereum-fork arbitrum-fork optimism-fork --mnemonic "$MNEMONIC" --deploy --config MyLzApp

In your test script, you can access getChain() in the HRE object. For example:

import { utils } from "ethers";
import { getChain } from "hardhat";

describe("MyLzApp", function () {
  it("should test", async function () {
    const ethereum = await getChain("ethereum-fork");
    const [deployer, alice, bob, carol] = await ethereum.getSigners();
  });
});

Chain object is defined as below:

export interface SignerWithAddress extends Signer {
  address: string;
}

export interface Snapshot {
  restore: () => Promise<void>;
  id: string;
}

export interface Chain {
  name: string;
  config: HttpNetworkConfig;
  provider: providers.JsonRpcProvider;
  snapshot: Snapshot;
  takeSnapshot: () => Promise<Snapshot>;
  getSigners: () => Promise<Array<SignerWithAddress>>;
  getSigner: (address: string) => Promise<SignerWithAddress>;
  getImpersonatedSigner: (
    address: string,
    balance?: BigNumberish
  ) => Promise<SignerWithAddress>;
  getContract: <T extends Contract>(
    name: string,
    signer?: Signer
  ) => Promise<T>;
  getContractAt: <T extends Contract>(
    nameOrAbi: string | unknown[],
    address: string,
    signer?: Signer
  ) => Promise<T>;
}

obscureozy/layer_zero-cli