Overview
Foundry is a Rust-based Ethereum development toolkit where tests are written in Solidity itself — no JavaScript needed. It's 10-100x faster than Hardhat for test execution and has first-class fuzz testing and invariant testing. Quickly becoming the industry standard for serious protocol development.
Pricing
✅ When to use
- Production-grade smart contracts requiring thorough testing and security analysis
- Fuzz testing and invariant testing to catch edge-case vulnerabilities automatically
- Teams who prefer writing tests in Solidity rather than switching to JavaScript
- CI pipelines where test execution speed matters — Foundry is dramatically faster
❌ When NOT to use
- Teams with strong TypeScript skills who prefer Hardhat's JS/TS ecosystem
- Projects needing Hardhat's specific plugin ecosystem (hardhat-deploy, typechain)
- Quick prototyping where Remix's browser IDE lets you start in under a minute
💡 Personal Tips
Foundry's fuzz testing has caught more bugs for me than all manual tests combined — add `function testFuzz_myFunc(uint256 amount) public` and Foundry automatically throws thousands of random inputs at it. The `forge test --match-test myTest -vvvv` flag gives a full execution trace for debugging. Anvil (the built-in local node) is faster and more configurable than Hardhat Network. The `cast` CLI tool is underrated: quick on-chain data queries, calling contract functions, sending transactions — all without writing scripts.