hardhat

What is hardhat?

Hardhat is a development environment to compile, deploy, test, and debug your Ethereum software. It helps developers manage and automate the recurring tasks that are inherent to the process of building smart contracts and dApps, as well as easily introducing more functionality around this workflow.

What are hardhat's main functionalities?

Compiling Smart Contracts

Hardhat can compile your smart contracts using the Solidity compiler. You can specify the version of Solidity you want to use in the configuration file.

module.exports = {
  solidity: "0.8.4",
};

Running Tests

Hardhat allows you to write tests for your smart contracts using popular testing frameworks like Mocha and Chai. This example shows a simple test for a token contract.

const { expect } = require("chai");

describe("Token contract", function () {
  it("Deployment should assign the total supply of tokens to the owner", async function () {
    const [owner] = await ethers.getSigners();
    const Token = await ethers.getContractFactory("Token");
    const hardhatToken = await Token.deploy();
    const ownerBalance = await hardhatToken.balanceOf(owner.address);
    expect(await hardhatToken.totalSupply()).to.equal(ownerBalance);
  });
});

Deploying Contracts

Hardhat makes it easy to deploy your smart contracts to the Ethereum network. This script deploys a token contract and logs the address to which it was deployed.

async function main() {
  const [deployer] = await ethers.getSigners();
  console.log("Deploying contracts with the account:", deployer.address);
  const Token = await ethers.getContractFactory("Token");
  const token = await Token.deploy();
  console.log("Token deployed to:", token.address);
}

main()
  .then(() => process.exit(0))
  .catch((error) => {
    console.error(error);
    process.exit(1);
  });

Debugging

Hardhat provides a powerful debugging tool that allows you to inspect the state of your contracts at any point in time. This example shows a custom task that prints the list of accounts.

const { task } = require("hardhat/config");

task("accounts", "Prints the list of accounts", async (taskArgs, hre) => {
  const accounts = await hre.ethers.getSigners();
  for (const account of accounts) {
    console.log(account.address);
  }
});

Other packages similar to hardhat

truffle

Truffle is a development environment, testing framework, and asset pipeline for Ethereum, aiming to make life as an Ethereum developer easier. It offers similar functionalities to Hardhat, such as compiling, deploying, and testing smart contracts. However, Hardhat is often praised for its flexibility and the ease of integrating with other tools.

embark

Embark is a framework for serverless Decentralized Applications using Ethereum, IPFS, and other platforms. It allows for easy development and deployment of smart contracts and dApps. Compared to Hardhat, Embark offers more out-of-the-box integrations with decentralized storage and communication protocols.

brownie

Brownie is a Python-based development and testing framework for smart contracts targeting the Ethereum Virtual Machine. It is similar to Hardhat in terms of functionalities but is more suited for developers who prefer Python over JavaScript.

README

Hardhat 3 Alpha

Hardhat 3 is a major overhaul with exciting new features:

• 🧪 Solidity tests as a first-class testing option
• 🌐 Multichain support for today's rollup-centric world
• ⚡ Rust-powered runtime for faster execution
• 🧱 Revamped build system with full npm compatibility and build profiles
• 🚀 Hardhat Ignition for streamlined contract deployments

It's currently in alpha state, but you can try it out and give us feedback!

Getting started

To install Hardhat 3, run the following commands in an empty directory:

npm init -y
npm install --save-dev hardhat@next
npx hardhat --init

This will take you through an interactive setup process to get started using Hardhat 3.

Learn more

To learn more about Hardhat 3, check out the Hardhat 3 Alpha documentation.

Feedback and help

If you have any questions, feedback, or need help, join the Hardhat 3 Alpha Telegram group.

Since this is still an alpha release, things will change, and your feedback can make a big difference. Let us know what you think and need!