Test like money depends on it

Frameworks like Foundry and Hardhat let you write tests that deploy contracts to a local chain, call functions, and assert results. Foundry tests are written in Solidity itself and run extremely fast.

Fuzz testing feeds thousands of random inputs into your functions to find edge cases you never imagined. Fork testing runs your contract against a copy of real mainnet state, so you can test integrations with live protocols safely.