Build the Audit Harness

Why this matters

Capstone of M1: every project you audit needs a harness — a Foundry repo that imports the target, sets up fork tests against real liquidity, exposes test helpers (named accounts, oracle mocks, time travel). The harness is reusable; once built for a protocol family (Uniswap forks, Aave forks), audits of new instances are 10× faster.

Demo

Harness contents: forge.toml with fork config, BaseTest.t.sol with shared setUp (deal accounts, deploy mocks, configure roles), MyProtocol.invariants.t.sol with property tests, helper libs for common assertions. Total: ~500 lines you write once, reuse forever.

Try it yourself

1. REPRODUCE — clone an open-source protocol you don't know. Stand up a Foundry project that forks mainnet at its deployment block. Write one trivial test that calls one function.
2. PATCH — add 5 invariants you'd want from the protocol. Run them; record findings.
3. VERIFY — abstract the harness into reusable helpers; spin up a second audit on a similar protocol in <1 hour.

References

• Foundry — Fork Testing
• Spearbit reports (modern audit examples)