feat(fuzz): keep observed calls out of corpus#15817
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decofe
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stevencartavia
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July 18, 2026 13:45
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TBD if this is desired 46180e7 I think also mutating immediately upon selecting an observed call remains |
Initialize the isolated coverage snapshots in the test-trace seeding path where they are consumed. Remove a stale test variable so the branch remains warning-free.
…entaur/observed-call-dictionary-1784381979
mablr
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Jul 23, 2026
| self.push_observed_sequence(tx_seq) | ||
| let mut added = 0; | ||
| for call in calls { | ||
| if !self.observed_call_pool.iter().any(|existing| { |
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This pool is unbounded and each insertion scans/compares every retained call, making distinct observed calls O(N^2) time plus unbounded calldata memory. We could use a dedupe set with a bounded reservoir/LRU.
| pub fn new_tx(&self, test_runner: &mut TestRunner) -> Result<BasicTxDetails> { | ||
| // Keep synthesizing fresh calls, but regularly use coverage-winning observed shapes as | ||
| // generation seeds. They are deliberately separate from corpus selection and persistence. | ||
| if !self.observed_call_pool.is_empty() && test_runner.rng().random_ratio(1, 2) { |
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Calls to run-local created contracts remain in this pool after those targets are cleared, so this fixed 50% path can increasingly select dead addresses. We could prune/tag dynamic-target entries at run end (and consider making this rate weighted rather than fixed).
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Stacked on #15816.
Keep coverage-winning observed calls in a separate, deduplicated generation dictionary, analogous to Echidna
GenDict.wholeCalls. Sibling zero-input tests contribute direct observed calls only when their execution adds coverage; they are never persisted or counted as corpus entries. A later fuzz execution must gain coverage before normal corpus promotion.Validation:
cargo +nightly fmtandgit diff --checkpass. Focusedfoundry-evmtests are blocked before compilation because Cargo cannot fetch the pinnedfoundry-rs/optimismGit dependency (HTTP 401).Prompted by: @0xalpharush