Hardhat vs Foundry

You can read the full article for this project in the Chainstack blog

This repository contains two similar projects built with Hardhat and Foundry.

Differences

	Foundry	Hardhat
Installation	via CLI curl command	not required with NPX, or via NPM
CLI tools	forge to manage the project (build/compile) & cast to interact with smart contracts	hardhat manage the project (build/compile/run scripts)
Build & test performance	💨💨💨💨💨	🐢🐢
Configuration file	foundry.toml	hardhat.config.js
Allows project folder configuration	Yes, in foundry.toml file	Yes, in hardhat.config.js file
Dependency management	GitHub submodules (any repository)	NPM packages
Dependencies file	.gitmodules	package.json
Files included in sample project	empty smart contract and basic test	Greeter smart contract (with set/get methods), test files and script to run locally
Test file format	Solidity contracts	JavaScript test files
Test assertion library (default)	ds-test	Mocha
Allows to alter blockchain status (time, block) in tests	Yes via cheatcodes	Limited, via mainnet forking.
Allows run specific tests?	Yes via --match-test --match-contract	Yes via "only" or "skip" in test files
Contract deployments	Via forge CLI or Bash scripts (new solutions in progress)	Via JS scripts
Blockchain / contracts interaction	via Cast CLI tool	N/A

Default project structure vs Hardhat

Files	Foundry	Hardhat
Contract files	/src	/contracts
Test files	/src/test	/test
Output	/out	/artifacts
Dependencies	/lib	/node_modules

Testing with Foundry

Pros	Cons	Neither
No async/await	Test names not as descriptive as in JS tests	tests writen in solidity
Tests require less code	Cheats are difficult to understand at first
Tests run super fast	expectRevert assertion is weird
Auto-generated gas report	testFail only tests if the test fails, not if the error is what we expect