lez-fuzzing/targets_coverage.md

The project contains 9 distinct fuzz targets covering all four required categories:

Transaction decoding / instruction parsing

• fuzz_transaction_decoding.rs — raw &[u8] fed to the Borsh parser for NSSATransaction, Block, and HashableBlockData; checks no-panic and encode/decode round-trip identity.
• fuzz_encoding_roundtrip.rs — structured Arbitrary inputs through the custom to_bytes/from_bytes codec for PublicTransaction and ProgramDeploymentTransaction; different codec, different types, different invariant.

Stateless verification checks

• fuzz_stateless_verification.rs — calls the application-level transaction_stateless_check() and verifies idempotency (a passing check must pass a second time).
• fuzz_signature_verification.rs — directly exercises the cryptographic primitive layer (Signature::new / is_valid_for): correctness for the signing key, no-panic on garbage bytes, no-panic on cross-key mismatch.

State transition / execution engine

• fuzz_state_transition.rs — multi-transaction sequences with monotonically increasing block context; asserts that a rejected transaction leaves all genesis account balances unchanged.
• fuzz_replay_prevention.rs — applies the same transaction twice and asserts rejection on the second application (nonce consumed after first acceptance).
• fuzz_state_diff_computation.rs — exercises ValidatedStateDiff::from_public_transaction and verifies diff containment: only accounts declared in affected_public_account_ids() may appear in the diff.
• fuzz_validate_execute_consistency.rs — runs validate_on_state (read-only) and execute_check_on_state (mutating) on cloned state and checks bidirectional agreement: same success/failure verdict, and the diff matches the actual mutations in both directions.

Block verification / replayer logic

• fuzz_block_verification.rs — the only block-level target; decodes raw bytes as Block / HashableBlockData and verifies that block_hash() never panics and is deterministic.

Each target differs in entry-point API, input shape, types under test, and the specific invariant asserted, making all nine genuinely distinct.