hardhat

Define a module with buildModule() that calls m.contract() with constructor args, then run npx hardhat ignition deploy with the module path and --network flag. Ignition resolves dependencies, tracks state in ignition/deployments/, and supports verification via npx hardhat ignition verify.

Use Hardhat when TypeScript integration, complex deployment orchestration, or the plugin ecosystem matters. Use Foundry when compilation speed, fuzz testing, or Solidity-native tooling is the priority. Both can coexist via the hardhat-foundry plugin.

Set forking.url and a pinned blockNumber in the hardhat network config, using an archive-tier RPC like Alchemy Growth. Use impersonateAccount and setBalance from network-helpers to act as whale accounts, and loadFixture to cache fork snapshots.

Verification fails when constructor arguments, compiler version, or optimizer settings differ from the original deployment. Pass exact args via a --constructor-args file and confirm the solidity settings in hardhat.config.ts match the deployed build.

No. The current hardhat-toolbox bundles ethers v6, where parseEther is a standalone import, BigNumber is replaced by native bigint, and ethers.utils is removed. Code using BigNumber.from() or ethers.utils.* must be migrated.

Common causes are missing RPC environment variables for fork tests, short Mocha timeouts on slower CI machines, and state leakage between tests. Guard fork tests behind an env check, raise mocha.timeout, and use loadFixture for isolation.