Invariant testing

fuzz testinginvariant fuzzing

Property-based testing where a fuzzer hammers contract entry points and asserts user-defined invariants hold throughout.

Distinct from unit tests, which assert specific input/output pairs. Invariant testing (Foundry, Echidna) shines at exposing emergent state corruption — the kind of bug formal proofs catch but unit tests miss. A standard component of mature protocol CI pipelines.

Related terms

Formal verificationMathematical proof that a smart contract satisfies stated invariants under all reachable program states.
Audit reportA security firm's written review of smart-contract code, classifying findings by severity and tracking issuer responses.