foundry_evm/executors/invariant/

mod.rs

use crate::{
    executors::{
        DURATION_BETWEEN_METRICS_REPORT, EarlyExit, EvmError, Executor, RawCallResult,
        campaign::{
            CampaignCallKind, CampaignControl, CampaignEvent, CampaignSequenceOutcome,
            FuzzCampaign, FuzzCampaignMode,
        },
        corpus::{
            CorpusInsertionMode, DynamicTargetCtx, ReplayTarget, WorkerCorpus, WorkerCorpusSeed,
            persist_campaign_optimization,
        },
        fuzz::{
            FuzzBranchFrontier, FuzzFrontierRecorder, StatefulFuzzBranchFrontierArtifact,
            merge_frontiers, write_frontier_artifact,
        },
        worker_seed,
    },
    inspectors::Fuzzer,
};
use alloy_dyn_abi::{DynSolValue, JsonAbiExt};
use alloy_json_abi::{Function, StateMutability};
use alloy_primitives::{
    Address, Bytes, FixedBytes, I256, Selector, U256,
    map::{AddressMap, AddressSet, HashMap, hash_map::Entry as AddressMapEntry},
};
use alloy_sol_types::{SolCall, sol};
use campaign::{
    InvariantCampaignAggregator, InvariantCampaignSpec, InvariantCampaignState,
    InvariantWorkerOutput, InvariantWorkerPlan,
};
use eyre::{ContextCompat, Result, eyre};
use foundry_common::{
    TestFunctionExt,
    contracts::{ContractsByAddress, ContractsByArtifact},
    sh_eprintln, sh_println,
};
use foundry_config::{FuzzCorpusConfig, InvariantConfig, InvariantDepthMode, InvariantWorkers};
use foundry_evm_core::{
    constants::{
        CALLER, CHEATCODE_ADDRESS, DEFAULT_CREATE2_DEPLOYER, HARDHAT_CONSOLE_ADDRESS, MAGIC_ASSUME,
    },
    evm::FoundryEvmNetwork,
    precompiles::PRECOMPILES,
};
use foundry_evm_coverage::HitMaps;
use foundry_evm_fuzz::{
    BasicTxDetails, FuzzCase, FuzzFixtures, ObservedCall,
    invariant::{
        ArtifactFilters, FuzzRunIdentifiedContracts, InvariantContract, RandomCallGenerator,
        SenderFilters, TargetedContract, TargetedContracts,
    },
    strategies::{EvmFuzzState, FuzzState, TxGenerator, override_call_strat},
};
use foundry_evm_traces::{CallTraceArena, SparsedTraceArena};
use indicatif::ProgressBar;
use parking_lot::RwLock;
use proptest::{
    prelude::Rng,
    test_runner::{RngAlgorithm, TestRng, TestRunner},
};
use rayon::iter::{IntoParallelIterator, ParallelIterator};
use result::{assert_after_invariant, can_continue, invariant_preflight_check};
use revm::state::Account;
use serde::{Deserialize, Serialize};
use serde_json::{Value, json};
use std::{
    collections::{HashMap as Map, HashSet, btree_map::Entry},
    sync::Arc,
    time::{Duration, Instant, SystemTime, UNIX_EPOCH},
};

mod error;
pub(crate) use error::snapshot_edge_fingerprint;
pub use error::{
    FailureKey, HandlerAssertionFailure, InvariantFailures, InvariantFuzzError,
    handler_edge_fingerprint, handler_site_already_minimal,
};
mod campaign;

mod replay;
pub use replay::{ReplayErrorResult, replay_error, replay_run};

mod result;
pub use result::{InvariantFuzzTestResult, did_fail_on_assert};

mod shrink;
pub use shrink::{
    CheckSequenceFailureSite, CheckSequenceOptions, CheckSequenceOutcome, HandlerReplayOutcome,
    SequenceShrink, ShrinkCandidateKeys, ShrinkRun, ShrinkRunStats, check_sequence,
    check_sequence_value, replay_handler_failure_sequence, shrink_sequence_by_removing,
};

/// Minimum number of logical runs assigned to each auto invariant worker at the default invariant
/// depth.
///
/// Keeps short campaigns single-threaded and avoids producing many small rayon jobs.
const MIN_RUNS_PER_INVARIANT_WORKER: u32 = 10_000;
/// Baseline depth used to preserve the previous default-depth worker heuristic.
const DEFAULT_DEPTH_FOR_INVARIANT_WORKER_CAP: u32 = 500;
/// Minimum estimated handler calls assigned to each auto invariant worker.
const MIN_ESTIMATED_CALLS_PER_INVARIANT_WORKER: u64 =
    MIN_RUNS_PER_INVARIANT_WORKER as u64 * DEFAULT_DEPTH_FOR_INVARIANT_WORKER_CAP as u64;
/// Share of parallel workers reserved for selector focus mode.
const INVARIANT_FOCUS_WORKER_DIVISOR: usize = 8;

sol! {
    interface IInvariantTest {
        #[derive(Default)]
        struct FuzzSelector {
            address addr;
            bytes4[] selectors;
        }

        #[derive(Default)]
        struct FuzzArtifactSelector {
            string artifact;
            bytes4[] selectors;
        }

        #[derive(Default)]
        struct FuzzInterface {
            address addr;
            string[] artifacts;
        }

        function afterInvariant() external;

        #[derive(Default)]
        function excludeArtifacts() public view returns (string[] memory excludedArtifacts);

        #[derive(Default)]
        function excludeContracts() public view returns (address[] memory excludedContracts);

        #[derive(Default)]
        function excludeSelectors() public view returns (FuzzSelector[] memory excludedSelectors);

        #[derive(Default)]
        function excludeSenders() public view returns (address[] memory excludedSenders);

        #[derive(Default)]
        function targetArtifacts() public view returns (string[] memory targetedArtifacts);

        #[derive(Default)]
        function targetArtifactSelectors() public view returns (FuzzArtifactSelector[] memory targetedArtifactSelectors);

        #[derive(Default)]
        function targetContracts() public view returns (address[] memory targetedContracts);

        #[derive(Default)]
        function targetSelectors() public view returns (FuzzSelector[] memory targetedSelectors);

        #[derive(Default)]
        function targetSenders() public view returns (address[] memory targetedSenders);

        #[derive(Default)]
        function targetInterfaces() public view returns (FuzzInterface[] memory targetedInterfaces);
    }
}

/// Contains invariant metrics for a single fuzzed selector.
#[derive(Default, Debug, Clone, Deserialize, Serialize, PartialEq, Eq)]
pub struct InvariantMetrics {
    // Count of fuzzed selector calls.
    pub calls: usize,
    // Count of fuzzed selector reverts.
    pub reverts: usize,
    // Count of fuzzed selector discards (through assume cheatcodes).
    pub discards: usize,
}

impl InvariantMetrics {
    const fn record_call(&mut self, reverted: bool, discarded: bool) {
        self.calls += 1;
        if discarded {
            self.discards += 1;
        } else if reverted {
            self.reverts += 1;
        }
    }
}

/// Campaign-level throughput metrics for invariant progress reporting.
#[derive(Debug, Default, Clone, Copy, PartialEq, Eq)]
struct InvariantThroughputMetrics {
    total_txs: u64,
    total_gas: u64,
}

impl InvariantThroughputMetrics {
    fn tps(self, elapsed: Duration) -> f64 {
        round_rate_for_progress(rate_per_sec(self.total_txs as f64, elapsed))
    }

    fn gps(self, elapsed: Duration) -> f64 {
        round_rate_for_progress(rate_per_sec(self.total_gas as f64, elapsed))
    }
}

fn max_invariant_workers_for_campaign(runs: u32, depth: u32) -> usize {
    let estimated_calls = u64::from(runs) * u64::from(depth.max(1));
    usize::try_from((estimated_calls / MIN_ESTIMATED_CALLS_PER_INVARIANT_WORKER).max(1))
        .unwrap_or(usize::MAX)
}

fn invariant_run_depth(config: &InvariantConfig, runner: &mut TestRunner) -> u32 {
    match config.depth_mode {
        InvariantDepthMode::Fixed => config.depth,
        InvariantDepthMode::Random => {
            let min_depth = config.min_depth.max(1);
            if config.depth <= min_depth {
                config.depth.max(1)
            } else {
                runner.rng().random_range(min_depth..=config.depth)
            }
        }
    }
}

fn auto_invariant_worker_count(
    available_threads: usize,
    invariant_campaign_anchors: usize,
) -> usize {
    (available_threads.max(1) / invariant_campaign_anchors.max(1)).max(1)
}

fn invariant_worker_count_with_threads(
    config: &InvariantConfig,
    available_threads: usize,
    invariant_campaign_anchors: usize,
) -> usize {
    match config.workers {
        InvariantWorkers::Fixed(workers) => workers.get(),
        InvariantWorkers::Auto => {
            let requested =
                auto_invariant_worker_count(available_threads, invariant_campaign_anchors);
            if config.timeout.is_some() {
                requested
            } else {
                requested.min(max_invariant_workers_for_campaign(config.runs, config.depth))
            }
        }
    }
}

const fn invariant_worker_config(
    mut config: InvariantConfig,
    worker_id: u32,
    worker_count: usize,
) -> InvariantConfig {
    // Keep one- and two-worker campaigns on the stable default, but let one extra worker explore
    // the broader fresh-input setting once the user has enough workers to keep the exploratory
    // share below half of the campaign. The last worker does not receive remainder runs from
    // campaign sharding, so this keeps exposure bounded to one worker shard.
    let exploratory_worker_id = worker_count.saturating_sub(1) as u32;
    if worker_count > 2
        && worker_id == exploratory_worker_id
        && !config.corpus_random_sequence_weight_configured
        && config.corpus.corpus_random_sequence_weight
            == FuzzCorpusConfig::DEFAULT_CORPUS_RANDOM_SEQUENCE_WEIGHT
    {
        config.corpus.corpus_random_sequence_weight =
            FuzzCorpusConfig::ENSEMBLE_CORPUS_RANDOM_SEQUENCE_WEIGHT;
    }
    config
}

fn gas_report_samples_for_worker(total_samples: u32, worker_id: u32, worker_count: usize) -> usize {
    let total_samples = total_samples as usize;
    let worker_count = worker_count.max(1);
    total_samples / worker_count + usize::from((worker_id as usize) < total_samples % worker_count)
}

fn invariant_worker_collects_evm_cmp_log(
    config: &InvariantConfig,
    worker_id: u32,
    worker_count: usize,
) -> bool {
    config.corpus.collect_evm_cmp_log() && (worker_count <= 1 || worker_id == 0)
}

fn invariant_focus_worker_count(worker_count: usize) -> usize {
    if worker_count <= 1 {
        0
    } else {
        let max_focus_workers = if worker_count > 2 { worker_count - 2 } else { worker_count - 1 };
        (worker_count / INVARIANT_FOCUS_WORKER_DIVISOR).max(1).min(max_focus_workers)
    }
}

fn invariant_focus_worker_index(worker_id: u32, worker_count: usize) -> Option<usize> {
    let worker_id = worker_id as usize;
    let focus_workers = invariant_focus_worker_count(worker_count);
    if focus_workers == 0 || worker_id >= worker_count {
        return None;
    }

    let focus_worker_end = if worker_count > 2 { worker_count - 1 } else { worker_count };
    let first_focus_worker = focus_worker_end - focus_workers;
    (worker_id >= first_focus_worker && worker_id < focus_worker_end)
        .then(|| worker_id - first_focus_worker)
}

fn focused_campaign_seed_for_worker(
    campaign_seed: &InvariantCampaignSeed,
    plan: InvariantWorkerPlan,
    worker_count: usize,
    focus_seed: Option<U256>,
) -> Option<InvariantCampaignSeed> {
    let focus_index = invariant_focus_worker_index(plan.worker_id, worker_count)?;
    let targeted_contracts =
        focused_targeted_contracts(&campaign_seed.targeted_contracts, focus_index, focus_seed)?;

    Some(InvariantCampaignSeed {
        targeted_contracts,
        targets_are_updatable: false,
        ..campaign_seed.clone()
    })
}

fn campaign_seed_and_corpus_seed_for_worker(
    campaign_seed: &InvariantCampaignSeed,
    corpus_seed: &WorkerCorpusSeed,
    plan: InvariantWorkerPlan,
    worker_count: usize,
    include_cmp_seq: bool,
    focus_seed: Option<U256>,
) -> (InvariantCampaignSeed, WorkerCorpusSeed) {
    let worker_corpus_seed =
        corpus_seed.clone_for_worker(plan.worker_id as usize, worker_count, include_cmp_seq);
    let Some(worker_campaign_seed) =
        focused_campaign_seed_for_worker(campaign_seed, plan, worker_count, focus_seed)
    else {
        return (campaign_seed.clone(), worker_corpus_seed);
    };

    let mut worker_corpus_seed = worker_corpus_seed;
    worker_corpus_seed.retain_replayable(&worker_campaign_seed.targeted_contracts);
    (worker_campaign_seed, worker_corpus_seed)
}

fn focused_targeted_contracts(
    targeted_contracts: &TargetedContracts,
    focus_index: usize,
    focus_seed: Option<U256>,
) -> Option<TargetedContracts> {
    let mut seen = HashSet::new();
    let mut candidates = Vec::new();
    for (address, contract) in targeted_contracts.iter() {
        // Build from the effective selector set so user target/exclude config stays authoritative.
        for function in contract.abi_fuzzed_functions() {
            if seen.insert((*address, function.selector())) {
                candidates.push((*address, function.clone()));
            }
        }
    }
    if candidates.len() <= 1 {
        return None;
    }

    let seed_offset = focus_seed
        .map(|seed| (seed % U256::from(candidates.len())).to::<usize>())
        .unwrap_or_default();
    let candidate_index = (focus_index % candidates.len() + seed_offset) % candidates.len();
    let (address, function) = candidates[candidate_index].clone();
    let mut contract = targeted_contracts.get(&address)?.clone();
    contract.targeted_functions = vec![function];

    let mut focused = TargetedContracts::new();
    focused.insert(address, contract);
    Some(focused)
}

fn should_continue_invariant_worker(
    campaign_state: &InvariantCampaignState,
    runs: u32,
    plan: InvariantWorkerPlan,
) -> bool {
    if campaign_state.should_stop() {
        return false;
    }

    campaign_state.is_timed_campaign() || runs < plan.runs
}

fn invariant_worker_runner(
    runner: &mut TestRunner,
    worker_id: u32,
    seed: Option<U256>,
) -> TestRunner {
    if let Some(seed) = seed {
        let worker_seed = worker_seed(seed, worker_id);
        trace!(target: "forge::test", ?worker_seed, "deterministic seed for invariant worker {worker_id}");
        let rng = TestRng::from_seed(RngAlgorithm::ChaCha, &worker_seed.to_be_bytes::<32>());
        TestRunner::new_with_rng(runner.config().clone(), rng)
    } else if worker_id == 0 {
        runner.clone()
    } else {
        TestRunner::new_with_rng(runner.config().clone(), runner.new_rng())
    }
}

fn invariant_focus_seed(
    runner: &mut TestRunner,
    configured_seed: Option<U256>,
    worker_count: usize,
) -> Option<U256> {
    if invariant_focus_worker_count(worker_count) == 0 {
        return None;
    }
    configured_seed.or_else(|| {
        let mut rng = runner.new_rng();
        Some(U256::from_be_bytes(rng.random::<[u8; 32]>()))
    })
}

/// Converts a cumulative campaign total into an average per-second rate.
///
/// Returns `0.0` during the initial zero-elapsed startup window to avoid
/// dividing by zero while progress reporting is warming up.
fn rate_per_sec(total: f64, elapsed: Duration) -> f64 {
    let elapsed_secs = elapsed.as_secs_f64();
    if elapsed_secs > 0.0 { total / elapsed_secs } else { 0.0 }
}

fn round_rate_for_progress(rate: f64) -> f64 {
    (rate * 100.0).round() / 100.0
}

/// Tracks invariant failure counts during a campaign.
#[derive(Clone, Debug, Default)]
struct InvariantFailureMetrics {
    failures: u64,
    unique_failures: HashSet<String>,
    /// Unique handler-side assertion bugs found so far.
    broken_handlers: usize,
}

impl InvariantFailureMetrics {
    /// Records a failure and emits a structured JSON `"failure"` event.
    fn record_failure(&mut self, invariant_name: &str, target: &str, reason: &str) {
        self.failures += 1;
        self.unique_failures.insert(invariant_name.to_string());

        let timestamp =
            SystemTime::now().duration_since(UNIX_EPOCH).map(|d| d.as_secs()).unwrap_or(0);
        let event = json!({
            "timestamp": timestamp,
            "event": "failure",
            "invariant": invariant_name,
            "target": target,
            "reason": reason,
        });
        let _ = sh_eprintln!("{}", serde_json::to_string(&event).unwrap_or_default());
    }

    /// Records a handler assertion and emits a structured JSON `"failure"` event.
    fn record_handler_failure(&mut self, target: Address, selector: Selector, reason: &str) {
        self.broken_handlers += 1;

        let timestamp =
            SystemTime::now().duration_since(UNIX_EPOCH).map(|d| d.as_secs()).unwrap_or(0);
        let event = build_handler_failure_event(timestamp, target, selector, reason);
        let _ = sh_eprintln!("{}", serde_json::to_string(&event).unwrap_or_default());
    }
}

fn build_handler_failure_event(
    timestamp_secs: u64,
    target: Address,
    selector: Selector,
    reason: &str,
) -> Value {
    json!({
        "timestamp": timestamp_secs,
        "event": "failure",
        "failure_type": "handler_assertion",
        "target": target,
        "selector": selector,
        "reason": reason,
    })
}

/// Bridges newly-recorded invariant breaks from `failures.errors` into the pulse
/// `failure_metrics` so the live progress stream reflects breaks as they happen.
/// Iterates in declaration order so the emitted "failure" events are deterministic.
fn record_new_invariant_failures(
    campaign_state: &InvariantCampaignState,
    invariant_contract: &InvariantContract<'_>,
    failures: &InvariantFailures,
) {
    for (f, _) in &invariant_contract.invariant_fns {
        if let Some(failure) = failures.get_failure(f) {
            let reason = failure.revert_reason().unwrap_or_default();
            campaign_state.record_invariant_failure(&f.name, invariant_contract.name, &reason);
        }
    }
}

struct InvariantProgressContext<'a> {
    timestamp_secs: u64,
    contract_name: &'a str,
    optimization_best: Option<I256>,
    throughput: InvariantThroughputMetrics,
    elapsed: Duration,
    worker_id: u32,
    worker_count: usize,
    /// Time since this worker last saw a new edge, or `None` if it has not seen one yet.
    time_since_new_edge: Option<Duration>,
}

/// Builds the machine-readable invariant progress payload emitted during a
/// campaign.
///
/// This keeps the existing corpus progress metrics together with cumulative and
/// derived throughput fields so downstream benchmark tooling can consume a
/// single JSON event shape.
fn build_invariant_progress_json<M: Serialize>(
    context: InvariantProgressContext<'_>,
    corpus_metrics: &M,
    failure_metrics: &InvariantFailureMetrics,
) -> serde_json::Value {
    let mut metrics = serde_json::to_value(corpus_metrics).unwrap_or_default();
    if let Some(obj) = metrics.as_object_mut() {
        obj.insert("broken_invariants".to_string(), json!(failure_metrics.unique_failures.len()));
        obj.insert("broken_assertions".to_string(), json!(failure_metrics.broken_handlers));
    }

    let mut payload = json!({
        "timestamp": context.timestamp_secs,
        "event": "pulse",
        "contract": context.contract_name,
        "metrics": metrics,
        "total_txs": context.throughput.total_txs,
        "total_gas": context.throughput.total_gas,
        "tps": context.throughput.tps(context.elapsed),
        "gps": context.throughput.gps(context.elapsed),
        "worker": {
            "id": context.worker_id,
            "count": context.worker_count,
            // `null` until this worker sees its first edge.
            "secs_since_new_edge": context
                .time_since_new_edge
                .map(|d| d.as_secs_f64()),
        },
    });

    if let Some(best) = context.optimization_best {
        payload["optimization_best"] = json!(best.to_string());
    }

    payload
}

/// Contains data collected during invariant test runs.
struct InvariantTestData {
    // Number of completed invariant runs.
    runs: usize,
    // Number of completed fuzzed calls across all invariant runs.
    calls: usize,
    // Data related to reverts or failed assertions of the test.
    failures: InvariantFailures,
    // Calldata in the last invariant run.
    last_run_inputs: Vec<BasicTxDetails>,
    // Additional traces for gas report.
    gas_report_traces: Vec<Vec<CallTraceArena>>,
    // Line coverage information collected from all fuzzed calls.
    line_coverage: Option<HitMaps>,
    // Metrics for each fuzzed selector.
    metrics: HashMap<String, InvariantMetrics>,
    // Cache from fuzzed (target, selector) to its metric key. Only resolved keys are cached and
    // they are invalidated when targets change (see `invalidate_metric_key_cache`).
    metric_key_cache: HashMap<(Address, Selector), String>,

    // Proptest runner to query for random values.
    // The strategy only comes with the first `input`. We fill the rest of the `inputs`
    // until the desired `depth` so we can use the evolving fuzz dictionary
    // during the run.
    branch_runner: TestRunner,

    // Optimization mode state: tracks the best (maximum) value and the sequence that produced it.
    // Only used when invariant function returns int256.
    optimization_best_value: Option<I256>,
    optimization_best_sequence: Vec<BasicTxDetails>,
}

/// Contains invariant test data.
struct InvariantTest {
    // Fuzz state of invariant test.
    fuzz_state: FuzzState,
    // Contracts fuzzed by the invariant test.
    targeted_contracts: FuzzRunIdentifiedContracts,
    // Data collected during invariant runs.
    test_data: InvariantTestData,
}

impl InvariantTest {
    /// Instantiates an invariant test.
    fn new(
        fuzz_state: FuzzState,
        targeted_contracts: FuzzRunIdentifiedContracts,
        failures: InvariantFailures,
        branch_runner: TestRunner,
    ) -> Self {
        let test_data = InvariantTestData {
            runs: 0,
            calls: 0,
            failures,
            last_run_inputs: vec![],
            gas_report_traces: vec![],
            line_coverage: None,
            metrics: HashMap::default(),
            metric_key_cache: HashMap::default(),
            branch_runner,
            optimization_best_value: None,
            optimization_best_sequence: vec![],
        };
        Self { fuzz_state, targeted_contracts, test_data }
    }

    /// Returns number of invariant test reverts.
    const fn reverts(&self) -> usize {
        self.test_data.failures.reverts
    }

    /// Set invariant test error.
    fn set_error(&mut self, invariant: &Function, error: InvariantFuzzError) {
        self.test_data.failures.record_failure(invariant, error);
    }

    /// Set last invariant run call sequence.
    fn set_last_run_inputs(&mut self, inputs: &Vec<BasicTxDetails>) {
        self.test_data.last_run_inputs.clone_from(inputs);
    }

    /// Merge current collected line coverage with the new coverage from last fuzzed call.
    fn merge_line_coverage(&mut self, new_coverage: Option<HitMaps>) {
        HitMaps::merge_opt(&mut self.test_data.line_coverage, new_coverage);
    }

    /// Update metrics for a fuzzed selector, extracted from tx details.
    /// Always increments number of calls; discarded runs (through assume cheatcodes) are tracked
    /// separated from reverts.
    fn record_metrics(&mut self, tx_details: &BasicTxDetails, reverted: bool, discarded: bool) {
        let Some(selector) = tx_details
            .call_details
            .calldata
            .get(..4)
            .and_then(|selector| <[u8; 4]>::try_from(selector).ok())
            .map(Selector::from)
        else {
            return;
        };
        let cache_key = (tx_details.call_details.target, selector);

        if let Some(metric_key) = self.test_data.metric_key_cache.get(&cache_key) {
            if let Some(invariant_metrics) = self.test_data.metrics.get_mut(metric_key) {
                invariant_metrics.record_call(reverted, discarded);
            } else {
                self.test_data
                    .metrics
                    .entry(metric_key.to_owned())
                    .or_default()
                    .record_call(reverted, discarded);
            }
            return;
        }

        // Not cached: resolve from the current target set. Unresolved keys aren't cached so a tx
        // whose target isn't known yet is re-resolved once that target is added.
        let Some(metric_key) = self
            .targeted_contracts
            .targets()
            .fuzzed_metric_key_for_selector(tx_details.call_details.target, selector)
        else {
            return;
        };
        self.test_data.metric_key_cache.insert(cache_key, metric_key.clone());
        self.test_data.metrics.entry(metric_key).or_default().record_call(reverted, discarded);
    }

    /// Drops cached metric keys for the given addresses, keeping the cache coherent when targets
    /// are added or removed (an address can be reused for a different artifact across runs).
    fn invalidate_metric_key_cache(&mut self, addresses: &[Address]) {
        if addresses.is_empty() {
            return;
        }
        self.test_data.metric_key_cache.retain(|(addr, _), _| !addresses.contains(addr));
    }

    /// End invariant test run by collecting results, cleaning collected artifacts and reverting
    /// created fuzz state.
    fn end_run<FEN: FoundryEvmNetwork>(&mut self, run: InvariantTestRun<FEN>, gas_samples: usize) {
        // Clear contracts created during this run, dropping their cached metric keys so a reused
        // address can't resolve to a stale contract in a later run.
        self.invalidate_metric_key_cache(&run.created_contracts);
        self.targeted_contracts.clear_created_contracts(run.created_contracts);

        if self.test_data.gas_report_traces.len() < gas_samples {
            self.test_data
                .gas_report_traces
                .push(run.run_traces.into_iter().map(|arena| arena.arena).collect());
        }
        self.test_data.runs += 1;
        self.test_data.calls += run.fuzz_runs.len();

        // Revert state to not persist values between runs.
        self.fuzz_state.revert();
    }

    /// Updates the optimization state if the new value is better (higher) than the current best.
    fn update_optimization_value(&mut self, value: I256, sequence: &[BasicTxDetails]) {
        if self.test_data.optimization_best_value.is_none_or(|best| value > best) {
            self.test_data.optimization_best_value = Some(value);
            self.test_data.optimization_best_sequence = sequence.to_vec();
        }
    }
}

/// Contains data for an invariant test run.
struct InvariantTestRun<FEN: FoundryEvmNetwork> {
    // Invariant run call sequence.
    inputs: Vec<BasicTxDetails>,
    // Per-call EVM comparison operands (parallel to `inputs`), captured for I2S corpus mutation.
    cmp_seq: Vec<Vec<crate::inspectors::CmpOperands>>,
    // Current invariant run executor.
    executor: Executor<FEN>,
    // Invariant run stat reports (eg. gas usage).
    fuzz_runs: Vec<FuzzCase>,
    // Contracts created during current invariant run.
    created_contracts: Vec<Address>,
    // Traces of each call of the invariant run call sequence.
    run_traces: Vec<SparsedTraceArena>,
    // Current depth of invariant run.
    depth: u32,
    // Current assume rejects of the invariant run.
    rejects: u32,
    // Whether new coverage was discovered during this run.
    new_coverage: bool,
    // Line coverage staged until the run is accepted.
    line_coverage: Option<HitMaps>,
    // Whether this run's inputs should become the reported last run.
    save_last_run_inputs: bool,
    // For optimization mode: the best value found during this run (if any).
    optimization_value: Option<I256>,
    // For optimization mode: the length of the input prefix that produced the best value.
    optimization_prefix_len: usize,
}

/// Recorded call sequence used by corpus feedback and frontier recording.
struct RecordedCallSequence {
    inputs: Vec<BasicTxDetails>,
    cmp_seq: Vec<Vec<crate::inspectors::CmpOperands>>,
}

/// Immutable state selected once for a logical invariant campaign and cloned into each worker.
#[derive(Clone)]
struct InvariantCampaignSeed {
    artifact_filters: ArtifactFilters,
    sender_filters: SenderFilters,
    targeted_contracts: TargetedContracts,
    targets_are_updatable: bool,
    initial_handler_failures: Map<(Address, Selector), InvariantFuzzError>,
}

impl<FEN: FoundryEvmNetwork> InvariantTestRun<FEN> {
    /// Instantiates an invariant test run.
    fn new(first_input: BasicTxDetails, executor: Executor<FEN>, depth: usize) -> Self {
        let mut inputs = Vec::with_capacity(depth.saturating_add(1));
        inputs.push(first_input);
        Self {
            inputs,
            cmp_seq: Vec::with_capacity(depth),
            executor,
            fuzz_runs: Vec::with_capacity(depth),
            created_contracts: vec![],
            run_traces: vec![],
            depth: 0,
            rejects: 0,
            new_coverage: false,
            line_coverage: None,
            save_last_run_inputs: false,
            optimization_value: None,
            optimization_prefix_len: 0,
        }
    }

    /// Releases per-run corpus payloads once the worker corpus manager has consumed them.
    ///
    /// Successful runs only need `fuzz_runs`, traces, and created-contract bookkeeping for final
    /// reporting. Counterexample inputs are copied into `InvariantTestData::last_run_inputs`
    /// before this point, so retaining the full per-run input/cmp buffers until `end_run` only
    /// extends peak memory in long invariant campaigns.
    fn drop_corpus_payloads(&mut self) {
        self.inputs.clear();
        self.inputs.shrink_to_fit();
        self.cmp_seq.clear();
        self.cmp_seq.shrink_to_fit();
    }
}

/// Wrapper around any [`Executor`] implementer which provides fuzzing support using [`proptest`].
///
/// After instantiation, calling `invariant_fuzz` will proceed to hammer the deployed smart
/// contracts with inputs, until it finds a counterexample sequence. The provided [`TestRunner`]
/// contains all the configuration which can be overridden via [environment
/// variables](proptest::test_runner::Config)
pub struct InvariantExecutor<'a, FEN: FoundryEvmNetwork> {
    pub executor: Executor<FEN>,
    /// Proptest runner.
    runner: TestRunner,
    /// Configured fuzz seed used to derive deterministic invariant worker runners.
    fuzz_seed: Option<U256>,
    /// The invariant configuration
    config: InvariantConfig,
    /// Contracts deployed with `setUp()`
    setup_contracts: &'a ContractsByAddress,
    /// Contracts that are part of the project but have not been deployed yet. We need the bytecode
    /// to identify them from the stateset changes.
    project_contracts: &'a ContractsByArtifact,
    /// Filters contracts to be fuzzed through their artifact identifiers.
    artifact_filters: ArtifactFilters,
    /// Number of matching invariant campaign anchors in the current test pass.
    invariant_campaign_anchors: usize,
}

impl<'a, FEN: FoundryEvmNetwork> InvariantExecutor<'a, FEN> {
    /// Instantiates an invariant executor with the configured fuzz seed for deterministic worker
    /// runner derivation.
    pub fn new_with_fuzz_seed(
        executor: Executor<FEN>,
        runner: TestRunner,
        fuzz_seed: Option<U256>,
        config: InvariantConfig,
        setup_contracts: &'a ContractsByAddress,
        project_contracts: &'a ContractsByArtifact,
        invariant_campaign_anchors: usize,
    ) -> Self {
        Self {
            executor,
            runner,
            fuzz_seed,
            config,
            setup_contracts,
            project_contracts,
            artifact_filters: ArtifactFilters::default(),
            invariant_campaign_anchors,
        }
    }

    pub fn config(&self) -> InvariantConfig {
        self.config.clone()
    }

    /// Retains corpus replay and result aggregation without starting fresh invariant runs.
    pub const fn skip_fresh_runs(&mut self) {
        self.config.runs = 0;
        self.config.timeout = None;
    }

    /// Refs for tracking contracts deployed mid-sequence during corpus replay.
    pub const fn dynamic_target_ctx(&self) -> DynamicTargetCtx<'_> {
        DynamicTargetCtx {
            project_contracts: self.project_contracts,
            setup_contracts: self.setup_contracts,
            artifact_filters: &self.artifact_filters,
        }
    }

    /// Fuzzes any deployed contract and checks any broken invariant at `invariant_address`.
    ///
    /// `initial_handler_failures` pre-seeds the campaign's `broken_handlers` map with bugs
    /// recovered from disk by the runner's persisted-failure replay step, so the live
    /// progress bar and JSON pulse stream surface them from the first emission instead of
    /// jumping at the final report.
    pub fn invariant_fuzz(
        &mut self,
        invariant_contract: InvariantContract<'_>,
        fuzz_fixtures: &FuzzFixtures,
        fuzz_state: EvmFuzzState,
        progress: Option<&ProgressBar>,
        early_exit: &EarlyExit,
        initial_handler_failures: std::collections::HashMap<
            (Address, Selector),
            InvariantFuzzError,
        >,
    ) -> Result<InvariantFuzzTestResult> {
        let campaign_spec = InvariantCampaignSpec::new(self.config.runs);
        let worker_plans = campaign_spec.worker_plans(invariant_worker_count_with_threads(
            &self.config,
            rayon::current_num_threads(),
            self.invariant_campaign_anchors,
        ))?;
        let actual_worker_count = worker_plans.len();
        let campaign_seed =
            self.prepare_campaign_seed(&invariant_contract, initial_handler_failures)?;
        let replay_targets = FuzzRunIdentifiedContracts::new(
            campaign_seed.targeted_contracts.clone(),
            campaign_seed.targets_are_updatable,
        );
        let mut corpus_replay_executor = self.executor.clone();
        corpus_replay_executor.inspector_mut().collect_evm_cmp_log(
            invariant_worker_collects_evm_cmp_log(&self.config, 0, actual_worker_count),
        );
        let dynamic = self.dynamic_target_ctx();
        let mut corpus_seed = WorkerCorpusSeed::load_from_disk(
            &self.config.corpus,
            None,
            Some(&corpus_replay_executor),
            ReplayTarget {
                stateless: None,
                fuzzed_contracts: Some(&replay_targets),
                dynamic: Some(&dynamic),
                senders: Some(&campaign_seed.sender_filters),
            },
        )?;
        if invariant_contract.is_optimization()
            && let Some(best_value) = corpus_seed.optimization_best_value
        {
            let sequence = (0..corpus_seed.optimization_best_sequence.len()).collect::<Vec<_>>();
            let replayed = check_sequence_value(
                self.executor.clone(),
                &corpus_seed.optimization_best_sequence,
                &sequence,
                invariant_contract.address,
                invariant_contract.anchor_calldata(),
                self.config.fail_on_revert,
                &campaign_seed.targeted_contracts.keys().copied().collect::<Vec<_>>(),
            );
            if !matches!(replayed, Ok(Some(value)) if value == best_value) {
                // Keep the sequence in the mutation corpus, but do not report its stale value.
                corpus_seed.optimization_best_value = None;
                corpus_seed.optimization_best_sequence.clear();
            }
        }
        let mut runner = self.runner.clone();
        let config = self.config.clone();
        let setup_contracts = self.setup_contracts;
        let project_contracts = self.project_contracts;
        let base_executor = self.executor.clone();
        let focus_seed = invariant_focus_seed(&mut runner, self.fuzz_seed, actual_worker_count);
        let campaign_state =
            Arc::new(InvariantCampaignState::new(early_exit.clone(), self.config.timeout));

        let frontier_test = self
            .config
            .corpus
            .capture_branch_frontiers()
            .then(|| invariant_contract.anchor().clone());
        let mut worker_outputs = if actual_worker_count > 1 {
            let worker_jobs = worker_plans
                .into_iter()
                .map(|worker_plan| {
                    let worker_runner =
                        invariant_worker_runner(&mut runner, worker_plan.worker_id, self.fuzz_seed);
                    let gas_report_samples = gas_report_samples_for_worker(
                        config.gas_report_samples,
                        worker_plan.worker_id,
                        actual_worker_count,
                    );
                    let collect_cmp_log = invariant_worker_collects_evm_cmp_log(
                        &config,
                        worker_plan.worker_id,
                        actual_worker_count,
                    );
                    (worker_plan, worker_runner, gas_report_samples, collect_cmp_log)
                })
                .collect::<Vec<_>>();
            worker_jobs
                .into_par_iter()
                .map(|(worker_plan, worker_runner, gas_report_samples, collect_cmp_log)| {
                    let _guard =
                        info_span!("invariant_worker", id = worker_plan.worker_id).entered();
                    let timer = Instant::now();
                    let (worker_campaign_seed, worker_corpus_seed) =
                        campaign_seed_and_corpus_seed_for_worker(
                            &campaign_seed,
                            &corpus_seed,
                            worker_plan,
                            actual_worker_count,
                            collect_cmp_log,
                            focus_seed,
                        );
                    let output = Self::run_invariant_worker(
                        base_executor.clone(),
                        worker_runner,
                        config.clone(),
                        setup_contracts,
                        project_contracts,
                        worker_plan,
                        invariant_contract.clone(),
                        fuzz_fixtures,
                        fuzz_state.fork(),
                        progress,
                        &campaign_state,
                        worker_campaign_seed,
                        worker_corpus_seed,
                        actual_worker_count,
                        gas_report_samples,
                    );
                    if output.is_err() {
                        campaign_state.request_terminal_stop();
                    }
                    debug!("finished in {:?}", timer.elapsed());
                    output
                })
                .collect::<Result<Vec<_>>>()?
        } else {
            let worker_plan = worker_plans[0];
            let runner =
                invariant_worker_runner(&mut runner, worker_plan.worker_id, self.fuzz_seed);
            let gas_report_samples = config.gas_report_samples as usize;
            let collect_cmp_log = invariant_worker_collects_evm_cmp_log(
                &config,
                worker_plan.worker_id,
                actual_worker_count,
            );
            let (worker_campaign_seed, worker_corpus_seed) =
                campaign_seed_and_corpus_seed_for_worker(
                    &campaign_seed,
                    &corpus_seed,
                    worker_plan,
                    actual_worker_count,
                    collect_cmp_log,
                    focus_seed,
                );
            vec![Self::run_invariant_worker(
                base_executor,
                runner,
                config,
                setup_contracts,
                project_contracts,
                worker_plan,
                invariant_contract,
                fuzz_fixtures,
                fuzz_state,
                progress,
                &campaign_state,
                worker_campaign_seed,
                worker_corpus_seed,
                actual_worker_count,
                gas_report_samples,
            )?]
        };

        let frontier_limit = self.config.corpus.frontier_limit;
        if let (Some(frontier_dir), Some(frontier_test)) =
            (&self.config.corpus.frontier_dir, frontier_test.as_ref())
        {
            let frontiers = merge_frontiers(
                frontier_limit,
                worker_outputs.iter_mut().flat_map(|(_, frontiers)| frontiers.drain(..)),
            );
            if !frontiers.is_empty() {
                let artifact = StatefulFuzzBranchFrontierArtifact::new(
                    frontier_test,
                    frontier_limit,
                    frontiers,
                );
                if let Err(err) = write_frontier_artifact(frontier_dir, &artifact) {
                    warn!(%err, path = ?frontier_dir, "failed to write fuzz branch frontier artifact");
                }
            }
        }

        let mut aggregator = InvariantCampaignAggregator::new(campaign_spec);
        for (worker_output, _) in worker_outputs {
            aggregator.push(worker_output);
        }
        let mut result = if campaign_state.is_timed_campaign() {
            aggregator.finish_partial()?
        } else {
            aggregator.finish_campaign()?
        };
        result.interrupted = campaign_state.interrupted(result.runs, self.config.runs);
        persist_campaign_optimization(
            &self.config.corpus,
            result.optimization_best_value,
            &result.optimization_best_sequence,
        );
        Ok(result)
    }

    /// Runs one worker-local slice of an invariant campaign.
    #[allow(clippy::too_many_arguments)]
    fn run_invariant_worker(
        mut executor: Executor<FEN>,
        runner: TestRunner,
        config: InvariantConfig,
        setup_contracts: &'a ContractsByAddress,
        project_contracts: &'a ContractsByArtifact,
        plan: InvariantWorkerPlan,
        invariant_contract: InvariantContract<'_>,
        fuzz_fixtures: &FuzzFixtures,
        fuzz_state: EvmFuzzState,
        progress: Option<&ProgressBar>,
        campaign_state: &InvariantCampaignState,
        campaign_seed: InvariantCampaignSeed,
        corpus_seed: WorkerCorpusSeed,
        worker_count: usize,
        gas_report_samples: usize,
    ) -> Result<(InvariantWorkerOutput, Vec<FuzzBranchFrontier>)> {
        // Note: invariant function signatures (no inputs) are validated upstream in the
        // suite runner so parameterized `invariant_*` functions are rejected with a per-test
        // failure entry before any campaign runs.
        let config = invariant_worker_config(config, plan.worker_id, worker_count);
        let frontier_limit = if config.corpus.capture_branch_frontiers()
            && invariant_worker_collects_evm_cmp_log(&config, plan.worker_id, worker_count)
        {
            config.corpus.frontier_limit
        } else {
            0
        };
        let mut frontier_recorder = FuzzFrontierRecorder::new(frontier_limit);
        executor.inspector_mut().set_execution_cancellation(campaign_state.cancellation().clone());

        let (mut invariant_test, mut corpus_manager) = Self::prepare_worker(
            &mut executor,
            plan,
            worker_count,
            &invariant_contract,
            fuzz_fixtures,
            fuzz_state,
            &runner,
            &config,
            &campaign_seed,
            corpus_seed,
        )?;
        let mut runs = 0;
        // Where the next view harvesting window starts; kept across runs so it keeps rotating.
        let mut view_cursor = 0;
        campaign_state.sync_handler_failures(&invariant_test.test_data.failures);
        // Report invariants that already fail in the initial state. Later runs only report
        // failures that they add.
        record_new_invariant_failures(
            campaign_state,
            &invariant_contract,
            &invariant_test.test_data.failures,
        );

        // Invariant runs with edge coverage if corpus dir is set or showing edge coverage.
        let edge_coverage_enabled = config.corpus.collect_edge_coverage();

        'stop: while should_continue_invariant_worker(campaign_state, runs, plan) {
            // Per-run failure count snapshot used to gate `afterInvariant` below.
            let failures_before_run = invariant_test.test_data.failures.invariant_count();
            let failures_checkpoint = invariant_test.test_data.failures.clone();
            let failures_revision = failures_checkpoint.revision();
            let mut stop_after_run = false;
            let mut run_cancelled = false;
            let mut observed_call_entries = Vec::<(Vec<ObservedCall>, BasicTxDetails)>::new();

            let call_campaign = FuzzCampaign::new(FuzzCampaignMode::Invariant {
                check_interval: config.check_interval,
                optimization: invariant_contract.is_optimization(),
            });

            let sequence_plan =
                corpus_manager.new_sequence(&mut invariant_test.test_data.branch_runner)?;
            let initial_seq = sequence_plan.initial();

            let run_depth =
                invariant_run_depth(&config, &mut invariant_test.test_data.branch_runner);

            let mut corpus_run = Option::<RecordedCallSequence>::None;
            let mut frontier_run = (frontier_limit > 0).then(|| RecordedCallSequence {
                inputs: Vec::with_capacity(run_depth as usize),
                cmp_seq: Vec::with_capacity(run_depth as usize),
            });

            // Create current invariant run data.
            let mut current_run = InvariantTestRun::new(
                initial_seq[0].clone(),
                // Before each run, we must reset the backend state.
                executor.clone(),
                run_depth as usize,
            );

            // We stop the run immediately if we have reverted, and `fail_on_revert` is set.
            if config.fail_on_revert && invariant_test.reverts() > 0 {
                campaign_state.request_terminal_stop();
                return Err(eyre!("call reverted"));
            }

            let mut call_cmp_values = Vec::new();
            let mut call_new_coverage = false;
            let mut coverage_prefix_len = 0;
            let mut assertion_failure = false;
            let mut pre_merge_edges_hash = None;
            let mut handler = None;
            let mut abort_campaign = false;
            let sequence_outcome = call_campaign.run_sequence(
                &mut current_run,
                run_depth,
                |run| {
                    let tx = run.inputs.last_mut().expect("campaign always has a current input");
                    (&mut run.executor, tx)
                },
                |run| run.depth,
                |_| campaign_state.should_stop(),
                |current_run, event| {
                    match event {
                        CampaignEvent::Feedback(call_result) => {
                            let current_tx = current_run.inputs.last().ok_or_else(|| {
                                eyre!("no input generated to call fuzzed target.")
                            })?;
                            let sel_bytes: [u8; 4] = current_tx
                                .call_details
                                .calldata
                                .get(..4)
                                .and_then(|selector| selector.try_into().ok())
                                .unwrap_or_default();
                            handler =
                                Some((current_tx.call_details.target, Selector::from(sel_bytes)));
                            if let Some(fuzzer) =
                                current_run.executor.inspector_mut().fuzzer.as_mut()
                            {
                                invariant_test.fuzz_state.collect_fuzzer_values(fuzzer);
                            }
                            call_cmp_values = call_result.evm_cmp_values.take().unwrap_or_default();
                            let discarded = call_result.result.as_ref() == MAGIC_ASSUME;
                            if config.show_metrics {
                                invariant_test.record_metrics(
                                    current_tx,
                                    call_result.reverted,
                                    discarded,
                                );
                            }
                            HitMaps::merge_opt(
                                &mut current_run.line_coverage,
                                call_result.line_coverage.take(),
                            );
                            assertion_failure = !discarded
                                && did_fail_on_assert(call_result, &call_result.state_changeset);
                            pre_merge_edges_hash = assertion_failure
                                .then(|| error::snapshot_edge_fingerprint(call_result))
                                .flatten();
                            call_new_coverage = corpus_manager.merge_edge_coverage(call_result);
                            if call_new_coverage {
                                current_run.new_coverage = true;
                            }
                            let observed_calls = std::mem::take(&mut call_result.observed_calls);
                            if call_new_coverage && !observed_calls.is_empty() {
                                observed_call_entries.push((observed_calls, current_tx.clone()));
                            }
                        }
                        CampaignEvent::Check { result, kind, should_check } => {
                            let mut result =
                                result.take().expect("campaign check result is available");
                            if kind == CampaignCallKind::AssumptionRejected {
                                current_run.inputs.pop();
                                current_run.rejects += 1;
                                if current_run.rejects > config.max_assume_rejects {
                                    invariant_test.set_error(
                                        invariant_contract.anchor(),
                                        InvariantFuzzError::MaxAssumeRejects(
                                            config.max_assume_rejects,
                                        ),
                                    );
                                    campaign_state.request_terminal_stop();
                                    abort_campaign = true;
                                    return Ok(CampaignControl::Stop);
                                }
                                return Ok(CampaignControl::Continue);
                            }
                            debug_assert_eq!(kind, CampaignCallKind::Accepted);
                            if let Some(frontier_run) = &mut frontier_run {
                                frontier_run.inputs.push(
                                    current_run
                                        .inputs
                                        .last()
                                        .expect("accepted call has a campaign input")
                                        .clone(),
                                );
                                frontier_run.cmp_seq.push(call_cmp_values.clone());
                            }
                            if config.corpus.is_coverage_guided() {
                                let preserve_revert =
                                    invariant_contract.is_optimization() || config.has_delay();
                                let retain_for_corpus =
                                    !result.reverted || preserve_revert || call_new_coverage;
                                if let Some(corpus_run) = &mut corpus_run {
                                    if retain_for_corpus {
                                        corpus_run.inputs.push(
                                            current_run
                                                .inputs
                                                .last()
                                                .expect("accepted call has a campaign input")
                                                .clone(),
                                        );
                                        corpus_run
                                            .cmp_seq
                                            .push(std::mem::take(&mut call_cmp_values));
                                    }
                                } else if result.reverted && !preserve_revert && call_new_coverage {
                                    let mut cmp_seq = std::mem::take(&mut current_run.cmp_seq);
                                    cmp_seq.push(std::mem::take(&mut call_cmp_values));
                                    corpus_run = Some(RecordedCallSequence {
                                        inputs: current_run.inputs.clone(),
                                        cmp_seq,
                                    });
                                } else if !result.reverted || preserve_revert {
                                    current_run.cmp_seq.push(std::mem::take(&mut call_cmp_values));
                                }
                                if call_new_coverage {
                                    coverage_prefix_len = corpus_run
                                        .as_ref()
                                        .map_or(current_run.inputs.len(), |history| {
                                            history.inputs.len()
                                        });
                                }
                            }
                            let (handler_target, handler_selector) =
                                handler.take().expect("feedback precedes campaign checks");
                            let mut state_changeset = std::mem::take(&mut result.state_changeset);
                            if !result.reverted {
                                let mapping_slots = current_run
                                    .executor
                                    .inspector()
                                    .fuzzer
                                    .as_ref()
                                    .and_then(|fuzzer| fuzzer.mapping_slots.as_ref());
                                collect_data(
                                    &invariant_test,
                                    &mut state_changeset,
                                    current_run.inputs.last().expect("checked above"),
                                    &result,
                                    run_depth,
                                    mapping_slots,
                                );
                                if config.dictionary.include_view_values {
                                    collect_view_values(
                                        &invariant_test,
                                        &current_run.executor,
                                        &state_changeset,
                                        current_run.inputs.last().expect("checked above"),
                                        run_depth,
                                        &mut view_cursor,
                                    );
                                }
                            }

                            let created_before = current_run.created_contracts.len();
                            if let Err(error) =
                                &invariant_test.targeted_contracts.collect_created_contracts(
                                    &state_changeset,
                                    project_contracts,
                                    setup_contracts,
                                    &campaign_seed.artifact_filters,
                                    &mut current_run.created_contracts,
                                )
                            {
                                warn!(target: "forge::test", "{error}");
                            }
                            invariant_test.invalidate_metric_key_cache(
                                &current_run.created_contracts[created_before..],
                            );
                            current_run
                                .fuzz_runs
                                .push(FuzzCase { gas: result.gas_used, stipend: result.stipend });

                            let continues = if should_check {
                                let outcome = can_continue(
                                    &invariant_contract,
                                    &mut invariant_test,
                                    current_run,
                                    &config,
                                    result,
                                    &state_changeset,
                                    handler_target,
                                    handler_selector,
                                    assertion_failure,
                                    pre_merge_edges_hash,
                                )
                                .map_err(|error| eyre!(error.to_string()))?;
                                run_cancelled = outcome.cancelled;
                                outcome.continues
                            } else {
                                if result.reverted {
                                    invariant_test.test_data.failures.reverts += 1;
                                }
                                if assertion_failure {
                                    let call_reverted = result.reverted;
                                    error::record_handler_assertion_bug(
                                        &invariant_contract,
                                        &config,
                                        &invariant_test.targeted_contracts,
                                        &mut invariant_test.test_data.failures,
                                        &mut current_run.inputs,
                                        handler_target,
                                        handler_selector,
                                        pre_merge_edges_hash,
                                        result,
                                        call_reverted,
                                        invariant_contract.is_optimization(),
                                    );
                                    true
                                } else if result.reverted && config.fail_on_revert {
                                    let anchor = invariant_contract.anchor();
                                    let case_data = error::InvariantRunCtx {
                                        contract: &invariant_contract,
                                        config: &config,
                                        targeted_contracts: &invariant_test.targeted_contracts,
                                        calldata: &current_run.inputs,
                                    }
                                    .failed_case(anchor, config.fail_on_revert, false, result, &[]);
                                    invariant_test.test_data.failures.record_failure(
                                        anchor,
                                        InvariantFuzzError::Revert(case_data),
                                    );
                                    false
                                } else {
                                    if result.reverted
                                        && !invariant_contract.is_optimization()
                                        && !config.has_delay()
                                    {
                                        current_run.inputs.pop();
                                    }
                                    true
                                }
                            };

                            if run_cancelled {
                                return Ok(CampaignControl::Stop);
                            }
                            if !continues || current_run.depth == run_depth - 1 {
                                current_run.save_last_run_inputs = true;
                            }
                            if !continues {
                                if invariant_contract.invariant_fns.len() == 1
                                    || config.fail_on_revert
                                {
                                    campaign_state.request_terminal_stop();
                                    stop_after_run = true;
                                }
                                return Ok(CampaignControl::Stop);
                            }
                        }
                        CampaignEvent::Advance => current_run.depth += 1,
                        CampaignEvent::Next { discarded, depth } => {
                            current_run.inputs.push(sequence_plan.next(
                                &mut invariant_test.test_data.branch_runner,
                                discarded,
                                depth as usize,
                            )?);
                        }
                        CampaignEvent::PostCheck => {
                            // Multi-predicate campaigns keep running after earlier failures, but
                            // the hook must still execute on subsequent clean runs.
                            if !abort_campaign
                                && !run_cancelled
                                && invariant_contract.call_after_invariant
                                && invariant_test.test_data.failures.invariant_count()
                                    == failures_before_run
                            {
                                let (broken, hook_cancelled) = assert_after_invariant(
                                    &invariant_contract,
                                    &mut invariant_test,
                                    current_run,
                                    &config,
                                )
                                .map_err(|_| eyre!("Failed to call afterInvariant"))?;
                                if hook_cancelled {
                                    run_cancelled = true;
                                } else if broken.is_some() {
                                    current_run.save_last_run_inputs = true;
                                }
                            }
                        }
                    }
                    Ok(CampaignControl::Continue)
                },
            )?;
            if sequence_outcome == CampaignSequenceOutcome::Cancelled {
                // A timed-out partial run remains successful, matching the previous worker
                // behavior, but it must not be persisted or counted.
                run_cancelled = true;
            }
            if abort_campaign {
                break 'stop;
            }

            // The worker which requested a terminal stop for its own failure still owns a
            // complete failing run. All other campaign stops discard the partial run before any
            // corpus persistence or accounting.
            if campaign_state.should_stop() && !stop_after_run {
                run_cancelled = true;
            }

            if run_cancelled {
                let completed_finding =
                    invariant_test.test_data.failures.revision() != failures_revision;
                if completed_finding {
                    record_new_invariant_failures(
                        campaign_state,
                        &invariant_contract,
                        &invariant_test.test_data.failures,
                    );
                    campaign_state.sync_handler_failures(&invariant_test.test_data.failures);
                } else {
                    invariant_test.test_data.failures.clone_from(&failures_checkpoint);
                }
                break 'stop;
            }

            if invariant_test.test_data.failures.invariant_count() > failures_before_run {
                record_new_invariant_failures(
                    campaign_state,
                    &invariant_contract,
                    &invariant_test.test_data.failures,
                );
            }
            if invariant_test.test_data.failures.handler_count()
                > failures_checkpoint.handler_count()
            {
                campaign_state.sync_handler_failures(&invariant_test.test_data.failures);
            }

            for (observed_calls, parent_tx) in observed_call_entries {
                corpus_manager.hoist_observed_calls(
                    &observed_calls,
                    &parent_tx,
                    &invariant_test.targeted_contracts,
                    &campaign_seed.sender_filters,
                    CorpusInsertionMode::Live,
                );
            }

            // Extend corpus only after the run and its optional hook have completed.
            if let Some(frontier_run) = &frontier_run {
                frontier_recorder.capture_sequence(&frontier_run.inputs, &frontier_run.cmp_seq);
            }
            let optimization = current_run.optimization_value.map(|v| {
                let prefix = current_run.inputs[..current_run.optimization_prefix_len].to_vec();
                (v, prefix)
            });
            let mut corpus_inputs = corpus_run
                .as_ref()
                .map_or(current_run.inputs.as_slice(), |history| history.inputs.as_slice());
            let mut corpus_cmp_seq = corpus_run
                .as_ref()
                .map_or(current_run.cmp_seq.as_slice(), |history| history.cmp_seq.as_slice());
            if current_run.new_coverage && !invariant_contract.is_optimization() {
                corpus_inputs = &corpus_inputs[..coverage_prefix_len];
                corpus_cmp_seq = &corpus_cmp_seq[..coverage_prefix_len];
            }
            if worker_count > 1 {
                corpus_manager.process_inputs_for_campaign(
                    corpus_inputs,
                    corpus_cmp_seq,
                    current_run.new_coverage,
                    optimization,
                );
            } else {
                corpus_manager.process_inputs(
                    corpus_inputs,
                    corpus_cmp_seq,
                    current_run.new_coverage,
                    optimization,
                );
            }

            // End current invariant test run.
            if current_run.save_last_run_inputs {
                invariant_test.set_last_run_inputs(&current_run.inputs);
            }
            if let Some(value) = current_run.optimization_value {
                invariant_test.update_optimization_value(
                    value,
                    &current_run.inputs[..current_run.optimization_prefix_len],
                );
            }
            invariant_test.merge_line_coverage(current_run.line_coverage.take());
            for fuzz_run in &current_run.fuzz_runs {
                campaign_state.record_call(fuzz_run.gas);
            }
            current_run.drop_corpus_payloads();
            invariant_test.end_run(current_run, gas_report_samples);
            runs += 1;
            let total_runs = campaign_state.increment_runs();
            debug_assert!(
                campaign_state.is_timed_campaign() || total_runs <= config.runs,
                "worker runs were not distributed correctly"
            );
            if let Some(progress) = progress {
                progress.inc(1);
                campaign_state.sync_handler_failures(&invariant_test.test_data.failures);
                // Display current best value, corpus metrics, and failure counts.
                let best = invariant_test.test_data.optimization_best_value;
                let failure_metrics = campaign_state.failure_metrics();
                let broken = failure_metrics.unique_failures.len();
                let handler_bugs = failure_metrics.broken_handlers;
                let total_invariants = invariant_contract.invariant_fns.len();
                if edge_coverage_enabled || best.is_some() || broken > 0 || handler_bugs > 0 {
                    let mut msg = String::new();
                    if let Some(best) = best {
                        msg.push_str(&format!("best: {best}"));
                    }
                    if edge_coverage_enabled {
                        if !msg.is_empty() {
                            msg.push_str(", ");
                        }
                        msg.push_str(&format!("{}", corpus_manager.metrics));
                        match corpus_manager.time_since_new_edge() {
                            Some(elapsed) => msg.push_str(&format!(
                                "\n        - time since new edge: {:.1}s",
                                elapsed.as_secs_f64()
                            )),
                            None => msg.push_str("\n        - time since new edge: never"),
                        }
                    }
                    if broken > 0 {
                        if !msg.is_empty() {
                            msg.push_str(", ");
                        }
                        msg.push_str(&format!("❌ {broken}/{total_invariants} broken"));
                    }
                    if handler_bugs > 0 {
                        if !msg.is_empty() {
                            msg.push_str(", ");
                        }
                        msg.push_str(&format!("⚠ {handler_bugs} handler bug(s)"));
                    }
                    let msg =
                        if worker_count > 1 { format!("[w{}] {msg}", plan.worker_id) } else { msg };
                    progress.set_message(msg);
                }
            } else if edge_coverage_enabled
                && campaign_state.should_emit_metrics_report(DURATION_BETWEEN_METRICS_REPORT)
            {
                campaign_state.sync_handler_failures(&invariant_test.test_data.failures);
                let failure_metrics = campaign_state.failure_metrics();
                let (total_txs, total_gas) = campaign_state.throughput_totals();
                let throughput = InvariantThroughputMetrics { total_txs, total_gas };
                // Display corpus metrics inline as JSON.
                let metrics = build_invariant_progress_json(
                    InvariantProgressContext {
                        timestamp_secs: SystemTime::now().duration_since(UNIX_EPOCH)?.as_secs(),
                        contract_name: invariant_contract.name,
                        optimization_best: invariant_test.test_data.optimization_best_value,
                        throughput,
                        elapsed: campaign_state.elapsed(),
                        worker_id: plan.worker_id,
                        worker_count,
                        time_since_new_edge: corpus_manager.time_since_new_edge(),
                    },
                    &corpus_manager.metrics,
                    &failure_metrics,
                );
                let _ = sh_println!("{}", serde_json::to_string(&metrics)?);
            }

            if stop_after_run {
                break 'stop;
            }
        }

        trace!(?fuzz_fixtures);
        invariant_test.fuzz_state.log_stats();

        // Campaign-local terminal stops and deadlines must not suppress post-campaign shrinking.
        executor.inspector_mut().set_early_exit(campaign_state.early_exit().clone());
        Self::shrink_handler_failures(
            &config,
            &executor,
            &mut invariant_test.test_data,
            progress,
            campaign_state.early_exit(),
        );

        // Move out the final test data and drop worker-local fuzz state before returning this
        // worker's aggregate output. Long invariant campaigns can leave large dictionaries and
        // target state behind; once shrinking is complete, only `test_data` is needed.
        let InvariantTest { fuzz_state: _, targeted_contracts: _, test_data: result } =
            invariant_test;
        let reverts = result.failures.reverts;
        let (errors, handler_errors) = result.failures.partition();
        let worker_result = InvariantFuzzTestResult::new(
            errors,
            handler_errors,
            result.runs,
            result.calls,
            reverts,
            result.last_run_inputs,
            result.gas_report_traces,
            result.line_coverage,
            result.metrics.into_iter().collect(),
            if plan.worker_id == 0 { corpus_manager.failed_replays } else { 0 },
            1,
            result.optimization_best_value,
            result.optimization_best_sequence,
        );
        drop(corpus_manager);
        let reported_plan = if campaign_state.is_timed_campaign() {
            InvariantWorkerPlan { runs, ..plan }
        } else {
            // Sharded campaigns must report the original assigned range. Early worker exit changes
            // the number of executed runs, but it must not shrink `plan.runs`: following workers'
            // `first_global_run` offsets were computed from the original partition.
            plan
        };
        Ok((
            InvariantWorkerOutput { plan: reported_plan, result: worker_result },
            frontier_recorder.into_frontiers(),
        ))
    }

    fn shrink_handler_failures(
        config: &InvariantConfig,
        executor: &Executor<FEN>,
        result: &mut InvariantTestData,
        progress: Option<&ProgressBar>,
        early_exit: &EarlyExit,
    ) {
        let total = result.failures.handler_count();
        if total == 0 {
            return;
        }

        for (idx, error) in result.failures.handler_failures_mut().enumerate() {
            if early_exit.should_stop() {
                break;
            }
            let Some(failure) = error.as_handler_assertion_mut() else {
                continue;
            };
            let shrink_progress = shrink::ShrinkProgress::new(
                config,
                progress,
                &format!("handler {:#x}::{}", failure.reverter, failure.selector),
                Some((idx + 1, total)),
                None,
                false,
            );
            match shrink::shrink_handler_sequence(
                config,
                &failure.call_sequence,
                failure.edge_fingerprint,
                executor,
                &shrink_progress,
                early_exit,
            ) {
                Ok(shrunk) if !shrunk.is_empty() => {
                    failure.call_sequence = shrunk;
                }
                Ok(_) => {}
                Err(e) => trace!(target: "forge::test", "handler shrink failed: {e}"),
            }
        }
    }

    fn prepare_campaign_seed(
        &mut self,
        invariant_contract: &InvariantContract<'_>,
        initial_handler_failures: std::collections::HashMap<
            (Address, Selector),
            InvariantFuzzError,
        >,
    ) -> Result<InvariantCampaignSeed> {
        self.select_contract_artifacts(invariant_contract.address)?;
        let (sender_filters, targeted_contracts) =
            self.select_contracts_and_senders(invariant_contract.address)?;
        let targets_are_updatable = targeted_contracts.is_updatable;
        let targeted_contracts = targeted_contracts.targets().clone();

        Ok(InvariantCampaignSeed {
            artifact_filters: self.artifact_filters.clone(),
            sender_filters,
            targeted_contracts,
            targets_are_updatable,
            initial_handler_failures,
        })
    }

    /// Prepares worker-local structures to execute an invariant campaign slice.
    #[allow(clippy::too_many_arguments)]
    fn prepare_worker(
        executor: &mut Executor<FEN>,
        plan: InvariantWorkerPlan,
        worker_count: usize,
        invariant_contract: &InvariantContract<'_>,
        fuzz_fixtures: &FuzzFixtures,
        fuzz_state: EvmFuzzState,
        runner: &TestRunner,
        config: &InvariantConfig,
        campaign_seed: &InvariantCampaignSeed,
        corpus_seed: WorkerCorpusSeed,
    ) -> Result<(InvariantTest, WorkerCorpus)> {
        let fuzz_state = fuzz_state.into_invariant();
        let targeted_contracts = FuzzRunIdentifiedContracts::new(
            campaign_seed.targeted_contracts.clone(),
            campaign_seed.targets_are_updatable,
        );
        executor.inspector_mut().collect_evm_cmp_log(invariant_worker_collects_evm_cmp_log(
            config,
            plan.worker_id,
            worker_count,
        ));

        // Creates the invariant strategy.
        let generator = TxGenerator::invariant(
            fuzz_state.clone(),
            campaign_seed.sender_filters.clone(),
            targeted_contracts.clone(),
            config.clone(),
            fuzz_fixtures.clone(),
        );

        // If any of the targeted contracts have the storage layout enabled then we can sample
        // mapping values. To accomplish, we need to record the mapping storage slots and keys.
        let mapping_slots = targeted_contracts
            .targets()
            .iter()
            .any(|(_, t)| t.storage_layout.is_some())
            .then(AddressMap::default);

        // Set up fuzzer WITHOUT call_generator initially.
        // We defer call_override until after the initial invariant check to avoid
        // injecting random calls during setup which would break the invariant assertion.
        let extra_cheatcode_addresses = executor.inspector().extra_cheatcode_addresses();
        executor.inspector_mut().set_fuzzer(
            Fuzzer::new(config.dictionary.max_fuzz_dictionary_values, mapping_slots)
                .with_extra_cheatcode_addresses(extra_cheatcode_addresses)
                .with_call_recording(config.corpus.is_coverage_guided()),
        );

        // Let's make sure the invariant is sound before actually starting the run:
        // We'll assert the invariant in its initial state, and if it fails, we'll
        // already know if we can early exit the invariant run.
        // This does not count as a fuzz run. It will just register the revert.
        let mut failures = InvariantFailures::new();
        // Seed disk-recovered handler bugs so live counters reflect them from tick 0.
        for (&(addr, sel), err) in &campaign_seed.initial_handler_failures {
            failures.seed_handler_failure(addr, sel, err.clone());
        }
        invariant_preflight_check(
            invariant_contract,
            config,
            &targeted_contracts,
            executor,
            &[],
            &mut failures,
        )?;
        if let Some(fuzzer) = executor.inspector_mut().fuzzer.as_mut() {
            fuzz_state.collect_fuzzer_values(fuzzer);
            let _ = fuzzer.take_observed_calls();
        }
        let generator = foundry_evm_fuzz::sequence::SequenceGenerator::invariant_with_fixtures(
            generator,
            fuzz_state.clone(),
            fuzz_fixtures.clone(),
            targeted_contracts.clone(),
            &config.corpus,
        )?;
        let mut worker = WorkerCorpus::from_seed(
            plan.worker_id as usize,
            config.corpus.clone(),
            generator,
            corpus_seed,
        )?;

        if let Err(err) = worker.seed_from_test_traces(
            invariant_contract,
            &targeted_contracts,
            &campaign_seed.sender_filters,
            executor,
        ) {
            debug!(target: "corpus", %err, "failed to seed corpus from test traces");
        }

        // NOW enable call_override after the initial invariant check and corpus trace seeding have
        // passed. This allows `override_call_strat` to inject calls during actual fuzz runs for
        // reentrancy vulnerability detection.
        if config.call_override {
            let target_contract_ref = Arc::new(RwLock::new(Address::ZERO));

            // Collect handler addresses - these are the contracts we want to inject
            // reentrancy into (simulating malicious receive() functions).
            let handler_addresses: AddressSet =
                targeted_contracts.targets().keys().copied().collect();
            let override_targets = targeted_contracts
                .targets()
                .iter()
                .filter_map(|(address, contract)| {
                    let functions = contract.abi_fuzzed_functions().cloned().collect::<Vec<_>>();
                    (!functions.is_empty()).then_some((*address, functions))
                })
                .collect::<Vec<_>>();

            let call_generator = RandomCallGenerator::new(
                invariant_contract.address,
                handler_addresses,
                runner.clone(),
                override_call_strat(
                    fuzz_state.snapshot(),
                    override_targets,
                    target_contract_ref.clone(),
                    fuzz_fixtures.clone(),
                    config.dictionary.dictionary_weight,
                    config.corpus.payable_value_weight,
                ),
                target_contract_ref,
            );

            if let Some(fuzzer) = executor.inspector_mut().fuzzer.as_mut() {
                fuzzer.call_generator = Some(call_generator);
            }
        }

        let mut invariant_test =
            InvariantTest::new(fuzz_state, targeted_contracts, failures, runner.clone());

        // Seed invariant test with previously persisted optimization state,
        // but only if the current invariant is in optimization mode. Persisted optimization state
        // is a master-worker artifact loaded with the initial corpus.
        if invariant_contract.is_optimization() {
            let (opt_best_value, opt_best_sequence) = worker.optimization_initial_state();
            if let Some(value) = opt_best_value {
                invariant_test.update_optimization_value(value, &opt_best_sequence);
            }
        }

        Ok((invariant_test, worker))
    }

    /// Fills the `InvariantExecutor` with the artifact identifier filters (in `path:name` string
    /// format). They will be used to filter contracts after the `setUp`, and more importantly,
    /// during the runs.
    ///
    /// Also excludes any contract without any mutable functions.
    ///
    /// Priority:
    ///
    /// targetArtifactSelectors > excludeArtifacts > targetArtifacts
    pub fn select_contract_artifacts(&mut self, invariant_address: Address) -> Result<()> {
        let targeted_artifact_selectors = self
            .executor
            .call_sol_default(invariant_address, &IInvariantTest::targetArtifactSelectorsCall {});

        // Insert them into the executor `targeted_abi`.
        for IInvariantTest::FuzzArtifactSelector { artifact, selectors } in
            targeted_artifact_selectors
        {
            let identifier = self.validate_selected_contract(artifact, &selectors)?;
            self.artifact_filters.targeted.entry(identifier).or_default().extend(selectors);
        }

        let targeted_artifacts = self
            .executor
            .call_sol_default(invariant_address, &IInvariantTest::targetArtifactsCall {});
        let excluded_artifacts = self
            .executor
            .call_sol_default(invariant_address, &IInvariantTest::excludeArtifactsCall {});

        // Insert `excludeArtifacts` into the executor `excluded_abi`.
        for contract in excluded_artifacts {
            let identifier = self.validate_selected_contract(contract, &[])?;

            if !self.artifact_filters.excluded.contains(&identifier) {
                self.artifact_filters.excluded.push(identifier);
            }
        }

        // Exclude any artifact without mutable functions.
        for (artifact, contract) in self.project_contracts.iter() {
            if contract
                .abi
                .functions()
                .filter(|func| {
                    !matches!(
                        func.state_mutability,
                        alloy_json_abi::StateMutability::Pure
                            | alloy_json_abi::StateMutability::View
                    )
                })
                .count()
                == 0
                && !self.artifact_filters.excluded.contains(&artifact.identifier())
            {
                self.artifact_filters.excluded.push(artifact.identifier());
            }
        }

        // Insert `targetArtifacts` into the executor `targeted_abi`, if they have not been seen
        // before.
        for contract in targeted_artifacts {
            let identifier = self.validate_selected_contract(contract, &[])?;

            if !self.artifact_filters.targeted.contains_key(&identifier)
                && !self.artifact_filters.excluded.contains(&identifier)
            {
                self.artifact_filters.targeted.insert(identifier, vec![]);
            }
        }
        Ok(())
    }

    /// Makes sure that the contract exists in the project. If so, it returns its artifact
    /// identifier.
    fn validate_selected_contract(
        &mut self,
        contract: String,
        selectors: &[FixedBytes<4>],
    ) -> Result<String> {
        if let Some((artifact, contract_data)) =
            self.project_contracts.find_by_name_or_identifier(&contract)?
        {
            // Check that the selectors really exist for this contract.
            for selector in selectors {
                contract_data
                    .abi
                    .functions()
                    .find(|func| func.selector().as_slice() == selector.as_slice())
                    .wrap_err(format!("{contract} does not have the selector {selector:?}"))?;
            }

            return Ok(artifact.identifier());
        }
        eyre::bail!(
            "{contract} not found in the project. Allowed format: `contract_name` or `contract_path:contract_name`."
        );
    }

    /// Selects senders and contracts based on the contract methods `targetSenders() -> address[]`,
    /// `targetContracts() -> address[]` and `excludeContracts() -> address[]`.
    pub fn select_contracts_and_senders(
        &self,
        to: Address,
    ) -> Result<(SenderFilters, FuzzRunIdentifiedContracts)> {
        let targeted_senders =
            self.executor.call_sol_default(to, &IInvariantTest::targetSendersCall {});
        let mut excluded_senders =
            self.executor.call_sol_default(to, &IInvariantTest::excludeSendersCall {});
        // Extend with default excluded addresses - https://github.com/foundry-rs/foundry/issues/4163
        excluded_senders.extend([
            CHEATCODE_ADDRESS,
            HARDHAT_CONSOLE_ADDRESS,
            DEFAULT_CREATE2_DEPLOYER,
        ]);
        // Extend with precompiles - https://github.com/foundry-rs/foundry/issues/4287
        excluded_senders.extend(PRECOMPILES);
        let sender_filters = SenderFilters::new(targeted_senders, excluded_senders);

        let selected = self.executor.call_sol_default(to, &IInvariantTest::targetContractsCall {});
        let excluded = self.executor.call_sol_default(to, &IInvariantTest::excludeContractsCall {});

        let contracts = self
            .setup_contracts
            .iter()
            .filter(|&(addr, (identifier, _))| {
                // Include to address if explicitly set as target.
                if *addr == to && selected.contains(&to) {
                    return true;
                }

                *addr != to
                    && *addr != CHEATCODE_ADDRESS
                    && *addr != HARDHAT_CONSOLE_ADDRESS
                    && (selected.is_empty() || selected.contains(addr))
                    && (excluded.is_empty() || !excluded.contains(addr))
                    && self.artifact_filters.matches(identifier)
            })
            .map(|(addr, (identifier, abi))| {
                (
                    *addr,
                    TargetedContract::new(identifier.clone(), abi.clone())
                        .with_project_contracts(self.project_contracts),
                )
            })
            .collect();
        let mut contracts = TargetedContracts { inner: contracts };

        self.target_interfaces(to, &mut contracts)?;

        self.select_selectors(to, &mut contracts)?;
        self.exclude_default_storage_hook_callbacks(&mut contracts)?;

        // There should be at least one contract identified as target for fuzz runs.
        if contracts.is_empty() {
            eyre::bail!("No contracts to fuzz.");
        }
        if contracts.fuzzed_functions().next().is_none() {
            eyre::bail!("No functions to fuzz.");
        }

        Ok((sender_filters, FuzzRunIdentifiedContracts::new(contracts, selected.is_empty())))
    }

    /// Excludes registered storage-hook callbacks from implicit invariant targets.
    ///
    /// Explicit selector filters take precedence, so users can still target a callback
    /// intentionally.
    fn exclude_default_storage_hook_callbacks(
        &self,
        targeted_contracts: &mut TargetedContracts,
    ) -> Result<()> {
        let Some(cheatcodes) = self.executor.inspector().cheatcodes.as_deref() else {
            return Ok(());
        };
        let callbacks =
            cheatcodes
                .storage_load_hooks()
                .chain(cheatcodes.storage_store_hooks())
                .map(|(_, hook)| (hook.callback_target, Selector::from(hook.callback_selector)))
                .chain(cheatcodes.mapping_storage_store_hooks().map(|(_, _, hook)| {
                    (hook.callback_target, Selector::from(hook.callback_selector))
                }))
                .collect::<HashSet<_>>();

        for (target, selector) in callbacks {
            let Some(contract) = targeted_contracts.get_mut(&target) else { continue };
            if !contract.targeted_functions.is_empty()
                || contract.function_by_selector(selector).is_none()
            {
                continue;
            }
            contract.add_selectors([selector], true)?;
        }
        Ok(())
    }

    /// Extends the contracts and selectors to fuzz with the addresses and ABIs specified in
    /// `targetInterfaces() -> (address, string[])[]`. Enables targeting of addresses that are
    /// not deployed during `setUp` such as when fuzzing in a forked environment. Also enables
    /// targeting of delegate proxies and contracts deployed with `create` or `create2`.
    pub fn target_interfaces(
        &self,
        invariant_address: Address,
        targeted_contracts: &mut TargetedContracts,
    ) -> Result<()> {
        let interfaces = self
            .executor
            .call_sol_default(invariant_address, &IInvariantTest::targetInterfacesCall {});

        // Since `targetInterfaces` returns a tuple array there is no guarantee
        // that the addresses are unique this map is used to merge functions of
        // the specified interfaces for the same address. For example:
        // `[(addr1, ["IERC20", "IOwnable"])]` and `[(addr1, ["IERC20"]), (addr1, ("IOwnable"))]`
        // should be equivalent.
        let mut combined = TargetedContracts::new();

        // Loop through each address and its associated artifact identifiers.
        // We're borrowing here to avoid taking full ownership.
        for IInvariantTest::FuzzInterface { addr, artifacts } in &interfaces {
            // Identifiers are specified as an array, so we loop through them.
            for identifier in artifacts {
                // Try to find the contract by name or identifier in the project's contracts.
                if let Some((_, contract_data)) =
                    self.project_contracts.iter().find(|(artifact, _)| {
                        &artifact.name == identifier || &artifact.identifier() == identifier
                    })
                {
                    let abi = &contract_data.abi;
                    combined
                        // Check if there's an entry for the given key in the 'combined' map.
                        .entry(*addr)
                        // If the entry exists, extends its ABI with the function list.
                        .and_modify(|entry| {
                            // Extend the ABI's function list with the new functions.
                            entry.abi.functions.extend(abi.functions.clone());
                            entry.rebuild_function_lookups();
                        })
                        // Otherwise insert it into the map.
                        .or_insert_with(|| {
                            let mut contract =
                                TargetedContract::new(identifier.clone(), abi.clone());
                            contract.storage_layout =
                                contract_data.storage_layout.as_ref().map(Arc::clone);
                            contract
                        });
                }
            }
        }

        targeted_contracts.extend(combined.inner);

        Ok(())
    }

    /// Selects the functions to fuzz based on the contract method `targetSelectors()` and
    /// `targetArtifactSelectors()`.
    pub fn select_selectors(
        &self,
        address: Address,
        targeted_contracts: &mut TargetedContracts,
    ) -> Result<()> {
        for (address, (identifier, _)) in self.setup_contracts {
            if let Some(selectors) = self.artifact_filters.targeted.get(identifier) {
                self.add_address_with_functions(*address, selectors, false, targeted_contracts)?;
            }
        }

        let mut target_test_selectors = vec![];
        let mut excluded_test_selectors = vec![];

        // Collect contract functions marked as target for fuzzing campaign.
        let selectors =
            self.executor.call_sol_default(address, &IInvariantTest::targetSelectorsCall {});
        for IInvariantTest::FuzzSelector { addr, selectors } in selectors {
            if addr == address {
                target_test_selectors = selectors.clone();
            }
            self.add_address_with_functions(addr, &selectors, false, targeted_contracts)?;
        }

        // Collect contract functions excluded from fuzzing campaign.
        let excluded_selectors =
            self.executor.call_sol_default(address, &IInvariantTest::excludeSelectorsCall {});
        for IInvariantTest::FuzzSelector { addr, selectors } in excluded_selectors {
            if addr == address {
                // If fuzz selector address is the test contract, then record selectors to be
                // later excluded if needed.
                excluded_test_selectors = selectors.clone();
            }
            self.add_address_with_functions(addr, &selectors, true, targeted_contracts)?;
        }

        if target_test_selectors.is_empty()
            && let Some(target) = targeted_contracts.get(&address)
        {
            // If test contract is marked as a target and no target selector explicitly set, then
            // include only state-changing functions that are not reserved and selectors that are
            // not explicitly excluded.
            let selectors: Vec<_> = target
                .abi
                .functions()
                .filter_map(|func| {
                    if matches!(
                        func.state_mutability,
                        alloy_json_abi::StateMutability::Pure
                            | alloy_json_abi::StateMutability::View
                    ) || func.is_reserved()
                        || excluded_test_selectors.contains(&func.selector())
                    {
                        None
                    } else {
                        Some(func.selector())
                    }
                })
                .collect();
            self.add_address_with_functions(address, &selectors, false, targeted_contracts)?;
        }

        Ok(())
    }

    /// Adds the address and fuzzed or excluded functions to `TargetedContracts`.
    fn add_address_with_functions(
        &self,
        address: Address,
        selectors: &[Selector],
        should_exclude: bool,
        targeted_contracts: &mut TargetedContracts,
    ) -> eyre::Result<()> {
        // Do not add address in target contracts if no function selected.
        if selectors.is_empty() {
            return Ok(());
        }

        let contract = match targeted_contracts.entry(address) {
            Entry::Occupied(entry) => entry.into_mut(),
            Entry::Vacant(entry) => {
                let (identifier, abi) = self.setup_contracts.get(&address).ok_or_else(|| {
                    eyre::eyre!(
                        "[{}] address does not have an associated contract: {}",
                        if should_exclude { "excludeSelectors" } else { "targetSelectors" },
                        address
                    )
                })?;
                entry.insert(
                    TargetedContract::new(identifier.clone(), abi.clone())
                        .with_project_contracts(self.project_contracts),
                )
            }
        };
        contract.add_selectors(selectors.iter().copied(), should_exclude)?;
        Ok(())
    }
}

/// Collects data from call for fuzzing. However, it first verifies that the sender is not an EOA
/// before inserting it into the dictionary. Otherwise, we flood the dictionary with
/// randomly generated addresses.
fn collect_data<FEN: FoundryEvmNetwork>(
    invariant_test: &InvariantTest,
    state_changeset: &mut AddressMap<Account>,
    tx: &BasicTxDetails,
    call_result: &RawCallResult<FEN>,
    run_depth: u32,
    mapping_slots: Option<&AddressMap<foundry_common::mapping_slots::MappingSlots>>,
) {
    // We keep the nonce changes to apply later.
    let sender_changeset = match state_changeset.entry(tx.sender) {
        AddressMapEntry::Occupied(entry) => entry
            .get()
            .info
            .code
            .as_ref()
            .is_none_or(|code| code.is_empty())
            .then(|| entry.remove()),
        AddressMapEntry::Vacant(_) => None,
    };

    // Collect values from fuzzed call result and add them to fuzz dictionary.
    invariant_test.fuzz_state.collect_values_from_call(
        &invariant_test.targeted_contracts,
        tx,
        &call_result.result,
        &call_result.logs,
        &*state_changeset,
        run_depth,
        mapping_slots,
    );

    // Inject typed sancov trace-cmp operands into the fuzz dictionary.
    if let Some(cmp_values) = &call_result.sancov_cmp_values {
        invariant_test.fuzz_state.collect_typed_cmp_values(
            cmp_values.iter().map(|s| (s.width, alloy_primitives::B256::from(s.value))),
        );
    }
    // Re-add changes
    if let Some(changed) = sender_changeset {
        state_changeset.insert(tx.sender, changed);
    }
}

/// Maximum number of view calls made to harvest dictionary values after one invariant call.
const MAX_VIEW_CALLS_PER_TX: usize = 32;

/// Calls the view functions of targeted contracts that the successful call accessed (read or
/// written), and adds their decoded results to the fuzz dictionary, whole structs included.
///
/// Eligible views take no inputs or only addresses, which are bound to the call's sender, so
/// values such as `balanceOf(sender)` or a getter's struct describe the state the next calls
/// act on. Calls run against the committed state without changing it; reverted calls are ignored.
///
/// At most [`MAX_VIEW_CALLS_PER_TX`] views are called. When more are eligible, `view_cursor`
/// starts each call's window where the previous one ended, so views past the first window are
/// reached too; with a stable set of eligible views, every one is called in turn.
fn collect_view_values<FEN: FoundryEvmNetwork>(
    invariant_test: &InvariantTest,
    executor: &Executor<FEN>,
    state_changeset: &AddressMap<Account>,
    tx: &BasicTxDetails,
    run_depth: u32,
    view_cursor: &mut usize,
) {
    let calls = {
        let targets = invariant_test.targeted_contracts.targets();
        let mut candidates = targets
            .iter()
            .filter(|(address, _)| state_changeset.contains_key(*address))
            .flat_map(|(address, contract)| {
                contract
                    .abi
                    .functions()
                    .filter(|function| is_harvestable_view(function))
                    .map(move |function| (*address, function))
            })
            .collect::<Vec<_>>();
        if candidates.len() > MAX_VIEW_CALLS_PER_TX {
            let start = *view_cursor % candidates.len();
            candidates.rotate_left(start);
            candidates.truncate(MAX_VIEW_CALLS_PER_TX);
            *view_cursor = start + MAX_VIEW_CALLS_PER_TX;
        }
        candidates
            .into_iter()
            .map(|(address, function)| (address, function.clone()))
            .collect::<Vec<_>>()
    };

    for (address, function) in calls {
        let args = vec![DynSolValue::Address(tx.sender); function.inputs.len()];
        let Ok(calldata) = function.abi_encode_input(&args) else { continue };
        let Ok(call_result) = executor.call_raw(tx.sender, address, calldata.into(), U256::ZERO)
        else {
            continue;
        };
        if !call_result.reverted {
            invariant_test.fuzz_state.collect_values_from_view(
                &function,
                &call_result.result,
                run_depth,
            );
        }
    }
}

/// Returns whether a function is a view whose result can be harvested without fuzzed inputs.
fn is_harvestable_view(function: &Function) -> bool {
    matches!(function.state_mutability, StateMutability::View | StateMutability::Pure)
        && !function.outputs.is_empty()
        && function.inputs.iter().all(|input| input.ty == "address")
        && !function.name.starts_with("invariant")
        && !function.name.starts_with("target")
        && !function.name.starts_with("exclude")
}

/// Calls the `afterInvariant()` function on a contract.
/// Returns call result and if call succeeded.
/// The state after the call is not persisted.
///
/// Uses the handler-gate success check so a stale committed `GLOBAL_FAIL_SLOT` from a
/// previously-recorded handler bug doesn't false-positive this call (the slot is `1` from
/// the prior bug, but `afterInvariant` itself didn't write it in this changeset).
pub(crate) fn call_after_invariant_function<FEN: FoundryEvmNetwork>(
    executor: &Executor<FEN>,
    to: Address,
) -> Result<(RawCallResult<FEN>, bool), EvmError<FEN>> {
    let calldata = Bytes::from_static(&IInvariantTest::afterInvariantCall::SELECTOR);
    let mut call_result = executor.call_raw(CALLER, to, calldata, U256::ZERO)?;
    let success = executor.is_raw_call_mut_success_handler_gate(to, &mut call_result);
    Ok((call_result, success))
}

/// Calls the invariant function and returns call result and if succeeded.
///
/// Uses the handler-gate success check (same rationale as `call_after_invariant_function`):
/// the predicate is broken iff this call's own changeset writes `GLOBAL_FAIL_SLOT` (via `t()` /
/// `vm.assert*`) or the call reverts; a stale committed slot from a prior handler bug must not
/// poison every later predicate evaluation in the run.
pub(crate) fn call_invariant_function<FEN: FoundryEvmNetwork>(
    executor: &Executor<FEN>,
    address: Address,
    calldata: Bytes,
) -> Result<(RawCallResult<FEN>, bool)> {
    let mut call_result = executor.call_raw(CALLER, address, calldata, U256::ZERO)?;
    let success = executor.is_raw_call_mut_success_handler_gate(address, &mut call_result);
    Ok((call_result, success))
}

/// Executes an invariant replay fuzz call and returns the result.
///
/// This applies invariant replay semantics: warp/roll deltas are applied before the call and the
/// requested value is clamped to the sender balance. It is intended for invariant sequence replay,
/// shrinking, and artifact validation rather than as a general raw-call helper.
///
/// Applies any block timestamp (warp) and block number (roll) adjustments before the call.
pub fn execute_tx<FEN: FoundryEvmNetwork>(
    executor: &mut Executor<FEN>,
    tx: &BasicTxDetails,
) -> Result<RawCallResult<FEN>> {
    super::campaign::execute_invariant_tx(executor, &mut tx.clone())
}

/// Executes an invariant replay call on a validation executor and registers created targets.
///
/// This uses live campaign acceptance and commit behavior while allowing callers to update
/// updatable target sets before validating later calls in the same artifact.
pub fn execute_tx_and_register_created<FEN: FoundryEvmNetwork>(
    executor: &mut Executor<FEN>,
    tx: &BasicTxDetails,
    targeted_contracts: &FuzzRunIdentifiedContracts,
    dynamic_target_ctx: &DynamicTargetCtx<'_>,
    created_contracts: &mut Vec<Address>,
) -> Result<()> {
    let (kind, call_result) = super::campaign::execute_invariant_replay_tx(executor, tx)?;
    if kind == CampaignCallKind::AssumptionRejected {
        return Err(eyre!("invariant replay prefix rejected by vm.assume"));
    }
    targeted_contracts.collect_created_contracts(
        &call_result.state_changeset,
        dynamic_target_ctx.project_contracts,
        dynamic_target_ctx.setup_contracts,
        dynamic_target_ctx.artifact_filters,
        created_contracts,
    )?;
    Ok(())
}

#[cfg(test)]
mod tests {

    use super::*;
    use crate::executors::ExecutorBuilder;
    use alloy_evm::EvmEnv;
    use foundry_cheatcodes::CheatsConfig;
    use foundry_config::FuzzDictionaryConfig;
    use foundry_evm_core::{backend::Backend, evm::EthEvmNetwork};
    use foundry_evm_fuzz::CallDetails;
    use proptest::{
        prelude::any,
        strategy::{Strategy, ValueTree},
        test_runner::Config,
    };
    use revm::{
        bytecode::Bytecode,
        context::{Block, TxEnv},
        database::InMemoryDB,
    };
    use serde_json::json;
    use std::{sync::mpsc, thread};

    fn first_generated_u64(runner: &mut TestRunner) -> u64 {
        any::<u64>().new_tree(runner).unwrap().current()
    }

    fn test_runner() -> TestRunner {
        TestRunner::new(Config { failure_persistence: None, ..Default::default() })
    }

    fn seeded_test_runner(seed: U256) -> TestRunner {
        let config = Config { failure_persistence: None, ..Default::default() };
        let rng = TestRng::from_seed(RngAlgorithm::ChaCha, &seed.to_be_bytes::<32>());
        TestRunner::new_with_rng(config, rng)
    }

    #[test]
    fn assumption_rejection_restores_delayed_block_environment() {
        let backend = Backend::<EthEvmNetwork>::spawn(None).unwrap();
        let mut executor = ExecutorBuilder::default()
            .inspectors(|stack| stack.cheatcodes(Arc::new(CheatsConfig::default())))
            .gas_limit(1 << 24)
            .build(EvmEnv::default(), TxEnv::default(), backend, Default::default());
        let target = Address::repeat_byte(0x11);
        let mut code = vec![0x6e]; // PUSH15.
        code.extend_from_slice(MAGIC_ASSUME);
        code.extend_from_slice(&[0x60, 0x00, 0x52, 0x60, 0x0f, 0x60, 0x11, 0xf3]);
        executor.set_code(target, Bytecode::new_raw(Bytes::from(code))).unwrap();

        let initial_block = executor.evm_env().block_env.clone();
        let initial_cheatcode_block =
            executor.inspector().cheatcodes.as_ref().unwrap().block.clone();
        let expected_timestamp = initial_block.timestamp() + U256::from(10);
        let expected_number = initial_block.number() + U256::from(5);
        let tx = BasicTxDetails {
            warp: Some(U256::from(10)),
            roll: Some(U256::from(5)),
            sender: Address::ZERO,
            call_details: CallDetails { target, calldata: Bytes::new(), value: None },
        };
        let mut state = (executor, tx);
        let campaign = FuzzCampaign::new(FuzzCampaignMode::Invariant {
            check_interval: 1,
            optimization: false,
        });

        let outcome = campaign
            .run_sequence(
                &mut state,
                1,
                |state| (&mut state.0, &mut state.1),
                |_| 0,
                |_| false,
                |state, event| {
                    match event {
                        CampaignEvent::Feedback(_) => {
                            let block = &state.0.evm_env().block_env;
                            assert_eq!(block.timestamp(), expected_timestamp);
                            assert_eq!(block.number(), expected_number);
                            let block = state
                                .0
                                .inspector()
                                .cheatcodes
                                .as_ref()
                                .unwrap()
                                .block
                                .as_ref()
                                .unwrap();
                            assert_eq!(block.timestamp(), expected_timestamp);
                            assert_eq!(block.number(), expected_number);
                        }
                        CampaignEvent::Check { kind, .. } => {
                            assert_eq!(kind, CampaignCallKind::AssumptionRejected);
                            return Ok(CampaignControl::Stop);
                        }
                        _ => {}
                    }
                    Ok(CampaignControl::Continue)
                },
            )
            .unwrap();

        assert_eq!(outcome, CampaignSequenceOutcome::Stopped);
        assert_eq!(state.0.evm_env().block_env, initial_block);
        assert_eq!(state.0.inspector().cheatcodes.as_ref().unwrap().block, initial_cheatcode_block);

        let (kind, _) =
            crate::executors::campaign::execute_invariant_replay_tx(&mut state.0, &state.1)
                .unwrap();
        assert_eq!(kind, CampaignCallKind::AssumptionRejected);
        assert_eq!(state.0.evm_env().block_env, initial_block);
        assert_eq!(state.0.inspector().cheatcodes.as_ref().unwrap().block, initial_cheatcode_block);
    }

    #[test]
    fn invariant_worker_runner_preserves_seed_for_master_worker() {
        let seed = U256::from(0x1234);
        let mut seeded_runner = seeded_test_runner(seed);
        let mut parent = test_runner();
        let mut worker = invariant_worker_runner(&mut parent, 0, Some(seed));

        assert_eq!(first_generated_u64(&mut worker), first_generated_u64(&mut seeded_runner));
    }

    #[test]
    fn invariant_worker_runner_uses_seed_independent_of_parent_rng_state() {
        let seed = U256::from(0x1234);
        let mut parent = test_runner();
        let mut advanced_parent = test_runner();
        let _ = first_generated_u64(&mut advanced_parent);

        let mut worker = invariant_worker_runner(&mut parent, 1, Some(seed));
        let mut worker_from_advanced_parent =
            invariant_worker_runner(&mut advanced_parent, 1, Some(seed));

        assert_eq!(
            first_generated_u64(&mut worker),
            first_generated_u64(&mut worker_from_advanced_parent)
        );
    }

    #[test]
    fn invariant_focus_seed_preserves_configured_seed() {
        let configured_seed = U256::from(0x1234);
        let mut parent = test_runner();

        assert_eq!(
            invariant_focus_seed(&mut parent, Some(configured_seed), 2),
            Some(configured_seed)
        );
        assert_eq!(invariant_focus_seed(&mut parent, Some(configured_seed), 1), None);
    }

    #[test]
    fn invariant_focus_seed_uses_parent_rng_when_unconfigured() {
        let mut parent = seeded_test_runner(U256::ONE);
        let mut matching_parent = seeded_test_runner(U256::ONE);
        let mut different_parent = seeded_test_runner(U256::from(2));

        let focus_seed = invariant_focus_seed(&mut parent, None, 2).unwrap();

        assert_eq!(focus_seed, invariant_focus_seed(&mut matching_parent, None, 2).unwrap());
        assert_ne!(focus_seed, invariant_focus_seed(&mut different_parent, None, 2).unwrap());
        assert_eq!(invariant_focus_seed(&mut parent, None, 1), None);
    }

    #[test]
    fn invariant_progress_json_includes_throughput_fields() {
        let throughput = InvariantThroughputMetrics { total_txs: 2, total_gas: 50 };

        let payload = build_invariant_progress_json(
            InvariantProgressContext {
                timestamp_secs: 123,
                contract_name: "InvariantContract",
                optimization_best: Some(I256::try_from(42).unwrap()),
                throughput,
                elapsed: Duration::from_secs(10),
                worker_id: 1,
                worker_count: 4,
                time_since_new_edge: Some(Duration::from_secs(3)),
            },
            &json!({ "corpus_count": 7 }),
            &InvariantFailureMetrics::default(),
        );

        assert_eq!(payload["timestamp"], json!(123));
        assert_eq!(payload["contract"], json!("InvariantContract"));
        assert!(payload.get("invariant").is_none());
        assert_eq!(payload["metrics"]["corpus_count"], json!(7));
        assert_eq!(payload["metrics"]["broken_assertions"], json!(0));
        assert!(payload["metrics"].get("broken_handlers").is_none());
        assert_eq!(payload["total_txs"], json!(2));
        assert_eq!(payload["total_gas"], json!(50));
        assert_eq!(payload["tps"], json!(0.2));
        assert_eq!(payload["gps"], json!(5.0));
        assert!(payload.get("tx_per_sec").is_none());
        assert!(payload.get("gas_per_sec").is_none());
        assert_eq!(payload["worker"]["id"], json!(1));
        assert_eq!(payload["worker"]["count"], json!(4));
        assert_eq!(payload["optimization_best"], json!("42"));
    }

    #[test]
    fn invariant_worker_count_keeps_short_campaigns_single_worker() {
        assert_eq!(
            max_invariant_workers_for_campaign(0, DEFAULT_DEPTH_FOR_INVARIANT_WORKER_CAP),
            1
        );
        assert_eq!(
            max_invariant_workers_for_campaign(
                MIN_RUNS_PER_INVARIANT_WORKER - 1,
                DEFAULT_DEPTH_FOR_INVARIANT_WORKER_CAP
            ),
            1
        );
        assert_eq!(
            max_invariant_workers_for_campaign(
                MIN_RUNS_PER_INVARIANT_WORKER,
                DEFAULT_DEPTH_FOR_INVARIANT_WORKER_CAP
            ),
            1
        );
        assert_eq!(
            max_invariant_workers_for_campaign(
                MIN_RUNS_PER_INVARIANT_WORKER * 2,
                DEFAULT_DEPTH_FOR_INVARIANT_WORKER_CAP
            ),
            2
        );
        assert_eq!(max_invariant_workers_for_campaign(256, 100_000), 5);
    }

    #[test]
    fn invariant_run_depth_random_min_depth_zero_never_returns_zero() {
        let mut runner = test_runner();
        let config = InvariantConfig {
            depth: 8,
            min_depth: 0,
            depth_mode: InvariantDepthMode::Random,
            ..Default::default()
        };

        for _ in 0..128 {
            assert!((1..=8).contains(&invariant_run_depth(&config, &mut runner)));
        }
    }

    #[test]
    fn invariant_run_depth_fixed_zero_preserves_zero() {
        let mut runner = test_runner();
        let config = InvariantConfig {
            depth: 0,
            depth_mode: InvariantDepthMode::Fixed,
            ..Default::default()
        };

        assert_eq!(invariant_run_depth(&config, &mut runner), 0);
    }

    #[test]
    fn invariant_worker_config_keeps_single_worker_default() {
        let config = InvariantConfig::default();

        assert_eq!(
            invariant_worker_config(config, 0, 1).corpus.corpus_random_sequence_weight,
            FuzzCorpusConfig::DEFAULT_CORPUS_RANDOM_SEQUENCE_WEIGHT
        );
    }

    #[test]
    fn invariant_worker_config_uses_one_exploratory_worker_with_default_config() {
        let config = InvariantConfig::default();

        assert_eq!(
            invariant_worker_config(config.clone(), 0, 4).corpus.corpus_random_sequence_weight,
            FuzzCorpusConfig::DEFAULT_CORPUS_RANDOM_SEQUENCE_WEIGHT
        );
        assert_eq!(
            invariant_worker_config(config.clone(), 1, 4).corpus.corpus_random_sequence_weight,
            FuzzCorpusConfig::DEFAULT_CORPUS_RANDOM_SEQUENCE_WEIGHT
        );
        assert_eq!(
            invariant_worker_config(config.clone(), 2, 4).corpus.corpus_random_sequence_weight,
            FuzzCorpusConfig::DEFAULT_CORPUS_RANDOM_SEQUENCE_WEIGHT
        );
        assert_eq!(
            invariant_worker_config(config, 3, 4).corpus.corpus_random_sequence_weight,
            FuzzCorpusConfig::ENSEMBLE_CORPUS_RANDOM_SEQUENCE_WEIGHT
        );
    }

    #[test]
    fn invariant_worker_config_keeps_two_worker_campaign_on_default() {
        let config = InvariantConfig::default();

        assert_eq!(
            invariant_worker_config(config.clone(), 0, 2).corpus.corpus_random_sequence_weight,
            FuzzCorpusConfig::DEFAULT_CORPUS_RANDOM_SEQUENCE_WEIGHT
        );
        assert_eq!(
            invariant_worker_config(config, 1, 2).corpus.corpus_random_sequence_weight,
            FuzzCorpusConfig::DEFAULT_CORPUS_RANDOM_SEQUENCE_WEIGHT
        );
    }

    #[test]
    fn invariant_worker_config_uses_last_worker_for_three_worker_campaign() {
        let config = InvariantConfig::default();

        assert_eq!(
            invariant_worker_config(config.clone(), 0, 3).corpus.corpus_random_sequence_weight,
            FuzzCorpusConfig::DEFAULT_CORPUS_RANDOM_SEQUENCE_WEIGHT
        );
        assert_eq!(
            invariant_worker_config(config.clone(), 1, 3).corpus.corpus_random_sequence_weight,
            FuzzCorpusConfig::DEFAULT_CORPUS_RANDOM_SEQUENCE_WEIGHT
        );
        assert_eq!(
            invariant_worker_config(config, 2, 3).corpus.corpus_random_sequence_weight,
            FuzzCorpusConfig::ENSEMBLE_CORPUS_RANDOM_SEQUENCE_WEIGHT
        );
    }

    #[test]
    fn invariant_worker_config_preserves_explicit_corpus_random_sequence_weight() {
        let config = InvariantConfig {
            corpus: FuzzCorpusConfig {
                corpus_random_sequence_weight: 25,
                ..FuzzCorpusConfig::default()
            },
            corpus_random_sequence_weight_configured: true,
            ..InvariantConfig::default()
        };

        assert_eq!(
            invariant_worker_config(config.clone(), 1, 4).corpus.corpus_random_sequence_weight,
            25
        );
        assert_eq!(invariant_worker_config(config, 0, 1).corpus.corpus_random_sequence_weight, 25);

        let config = InvariantConfig {
            corpus_random_sequence_weight_configured: true,
            ..InvariantConfig::default()
        };

        assert_eq!(
            invariant_worker_config(config, 1, 4).corpus.corpus_random_sequence_weight,
            FuzzCorpusConfig::DEFAULT_CORPUS_RANDOM_SEQUENCE_WEIGHT
        );
    }

    #[test]
    fn invariant_worker_count_preserves_fixed_workers() {
        let mut config = InvariantConfig {
            runs: MIN_RUNS_PER_INVARIANT_WORKER * 4,
            workers: foundry_config::InvariantWorkers::Fixed(
                std::num::NonZeroUsize::new(4).unwrap(),
            ),
            ..Default::default()
        };
        assert_eq!(invariant_worker_count_with_threads(&config, 8, 1), 4);

        config.corpus.show_edge_coverage = true;
        assert_eq!(invariant_worker_count_with_threads(&config, 8, 1), 4);

        config.corpus.show_edge_coverage = false;
        config.corpus.corpus_dir = Some(std::path::PathBuf::from("corpus"));
        assert_eq!(invariant_worker_count_with_threads(&config, 8, 1), 4);

        config.runs = MIN_RUNS_PER_INVARIANT_WORKER - 1;
        config.timeout = None;
        assert_eq!(invariant_worker_count_with_threads(&config, 8, 1), 4);

        config.timeout = Some(1);
        assert_eq!(invariant_worker_count_with_threads(&config, 8, 4), 4);
    }

    #[test]
    fn invariant_worker_count_does_not_cap_configured_workers_by_available_threads() {
        let config = InvariantConfig {
            runs: MIN_RUNS_PER_INVARIANT_WORKER * 8,
            workers: foundry_config::InvariantWorkers::Fixed(
                std::num::NonZeroUsize::new(8).unwrap(),
            ),
            ..Default::default()
        };

        assert_eq!(invariant_worker_count_with_threads(&config, 4, 1), 8);
    }

    #[test]
    fn invariant_worker_count_splits_available_threads_for_auto_workers() {
        let mut config = InvariantConfig {
            runs: MIN_RUNS_PER_INVARIANT_WORKER * 4,
            depth: DEFAULT_DEPTH_FOR_INVARIANT_WORKER_CAP,
            workers: foundry_config::InvariantWorkers::Auto,
            ..Default::default()
        };

        assert_eq!(invariant_worker_count_with_threads(&config, 4, 1), 4);
        assert_eq!(invariant_worker_count_with_threads(&config, 8, 2), 4);
        assert_eq!(invariant_worker_count_with_threads(&config, 8, 3), 2);
        assert_eq!(invariant_worker_count_with_threads(&config, 3, 8), 1);
        assert_eq!(invariant_worker_count_with_threads(&config, 0, 0), 1);

        config.runs = MIN_RUNS_PER_INVARIANT_WORKER - 1;
        assert_eq!(invariant_worker_count_with_threads(&config, 8, 2), 1);

        config.depth = 100_000;
        assert_eq!(invariant_worker_count_with_threads(&config, 8, 2), 4);

        config.timeout = Some(1);
        assert_eq!(invariant_worker_count_with_threads(&config, 8, 2), 4);
    }

    fn function(signature: &str) -> Function {
        Function::parse(signature).unwrap()
    }

    fn targeted_contract(identifier: &str, functions: Vec<Function>) -> TargetedContract {
        let mut abi = alloy_json_abi::JsonAbi::new();
        for function in functions {
            abi.functions.entry(function.name.clone()).or_default().push(function);
        }
        TargetedContract::new(identifier.to_string(), abi)
    }

    #[test]
    fn campaign_terminal_stop_interrupts_handler_without_accepting_run() {
        const GAS_LIMIT: u64 = 1 << 24;
        let invariant_address = Address::repeat_byte(0x11);
        let handler_address = Address::repeat_byte(0x22);
        let backend = Backend::<EthEvmNetwork>::spawn(None).unwrap();
        let mut executor = ExecutorBuilder::default().gas_limit(GAS_LIMIT).build(
            EvmEnv::default(),
            TxEnv::default(),
            backend,
            Default::default(),
        );
        // Return ABI-encoded `true` for the invariant predicate.
        executor
            .set_code(
                invariant_address,
                Bytecode::new_raw(Bytes::from_static(&[
                    0x60, 0x01, 0x60, 0x00, 0x52, 0x60, 0x20, 0x60, 0x00, 0xf3,
                ])),
            )
            .unwrap();
        // JUMPDEST; PUSH1 0; JUMP loops until the campaign stop reaches the inspector.
        executor
            .set_code(
                handler_address,
                Bytecode::new_raw(Bytes::from_static(&[0x5b, 0x60, 0x00, 0x56])),
            )
            .unwrap();

        let (handler_entered_tx, handler_entered_rx) = mpsc::channel();
        let (handler_release_tx, handler_release_rx) = mpsc::channel();
        executor.inspector_mut().set_early_exit_test_gate(
            handler_entered_tx,
            handler_release_rx,
            0,
        );

        let invariant = function("invariant_ok() view returns (bool)");
        let mut invariant_abi = alloy_json_abi::JsonAbi::new();
        invariant_abi.functions.entry(invariant.name.clone()).or_default().push(invariant.clone());
        let invariant_contract = InvariantContract::new(
            invariant_address,
            "InvariantTest",
            vec![(&invariant, false)],
            0,
            false,
            &invariant_abi,
        );

        let handler = function("loopForever()");
        let mut handler_contract = targeted_contract("Handler", vec![handler.clone()]);
        handler_contract.targeted_functions = vec![handler];
        let mut targeted_contracts = TargetedContracts::new();
        targeted_contracts.insert(handler_address, handler_contract);
        let campaign_seed = InvariantCampaignSeed {
            artifact_filters: ArtifactFilters::default(),
            sender_filters: SenderFilters::new(vec![CALLER], Vec::new()),
            targeted_contracts,
            targets_are_updatable: false,
            initial_handler_failures: Map::default(),
        };

        let config =
            InvariantConfig { runs: 1, depth: 1, show_metrics: false, ..Default::default() };
        let campaign_state = InvariantCampaignState::new(EarlyExit::new(false), None);
        let fuzz_state =
            EvmFuzzState::new(&[], &InMemoryDB::default(), FuzzDictionaryConfig::default(), None);
        let setup_contracts = ContractsByAddress::default();
        let project_contracts = ContractsByArtifact::default();
        let (result_tx, result_rx) = mpsc::channel();

        let (handler_entered, result) = thread::scope(|scope| {
            let handle = scope.spawn(|| {
                let result = InvariantExecutor::<EthEvmNetwork>::run_invariant_worker(
                    executor,
                    test_runner(),
                    config,
                    &setup_contracts,
                    &project_contracts,
                    InvariantWorkerPlan { worker_id: 0, first_global_run: 0, runs: 1 },
                    invariant_contract,
                    &FuzzFixtures::default(),
                    fuzz_state,
                    None,
                    &campaign_state,
                    campaign_seed,
                    WorkerCorpusSeed::default(),
                    1,
                    1,
                );
                let _ = result_tx.send(result);
            });

            let handler_entered = handler_entered_rx.recv_timeout(Duration::from_secs(1)).is_ok();
            campaign_state.request_terminal_stop();
            let _ = handler_release_tx.send(());

            let result = result_rx.recv_timeout(Duration::from_secs(1));
            handle.join().unwrap();
            (handler_entered, result)
        });
        assert!(handler_entered, "invariant handler did not begin EVM execution");
        let (output, _) = result.expect("invariant campaign did not observe early exit").unwrap();
        assert_eq!(output.result.runs, 0);
        assert_eq!(output.result.calls, 0);
        assert_eq!(campaign_state.total_runs(), 0);
        assert_eq!(campaign_state.throughput_totals(), (0, 0));
        assert!(output.result.errors.is_empty());
        assert!(output.result.handler_errors.is_empty());
        assert!(output.result.last_run_inputs.is_empty());
        assert!(output.result.line_coverage.is_none());
        assert!(output.result.metrics.is_empty());
        assert!(output.result.optimization_best_value.is_none());
    }

    #[test]
    fn invariant_focus_workers_stay_before_exploratory_tail_worker() {
        assert_eq!(invariant_focus_worker_count(1), 0);
        assert_eq!(invariant_focus_worker_count(2), 1);
        assert_eq!(invariant_focus_worker_count(4), 1);
        assert_eq!(invariant_focus_worker_count(8), 1);
        assert_eq!(invariant_focus_worker_count(16), 2);

        assert_eq!(invariant_focus_worker_index(0, 1), None);
        assert_eq!(invariant_focus_worker_index(1, 2), Some(0));
        assert_eq!(invariant_focus_worker_index(0, 4), None);
        assert_eq!(invariant_focus_worker_index(2, 4), Some(0));
        assert_eq!(invariant_focus_worker_index(3, 4), None);
        assert_eq!(invariant_focus_worker_index(13, 16), Some(0));
        assert_eq!(invariant_focus_worker_index(14, 16), Some(1));
        assert_eq!(invariant_focus_worker_index(15, 16), None);
        assert_eq!(invariant_focus_worker_index(16, 16), None);
    }

    #[test]
    fn invariant_focus_narrows_to_one_effective_selector() {
        let target = Address::repeat_byte(0x11);
        let first = function("first(uint256)");
        let second = function("second(uint256)");
        let second_selector = second.selector();
        let mut contract = targeted_contract("Target", vec![first.clone(), second.clone()]);
        contract.targeted_functions = vec![first, second];

        let mut targets = TargetedContracts::new();
        targets.insert(target, contract);

        let focused = focused_targeted_contracts(&targets, 1, None).unwrap();
        let focused_functions = focused[&target].abi_fuzzed_functions().collect::<Vec<_>>();

        assert_eq!(focused.len(), 1);
        assert_eq!(focused_functions.len(), 1);
        assert_eq!(focused_functions[0].selector(), second_selector);
    }

    #[test]
    fn invariant_focus_seed_rotates_effective_selector() {
        let target = Address::repeat_byte(0x55);
        let first = function("first(uint256)");
        let second = function("second(uint256)");
        let third = function("third(uint256)");
        let third_selector = third.selector();
        let mut contract =
            targeted_contract("Target", vec![first.clone(), second.clone(), third.clone()]);
        contract.targeted_functions = vec![first, second, third];

        let mut targets = TargetedContracts::new();
        targets.insert(target, contract);

        let focused = focused_targeted_contracts(&targets, 0, Some(U256::from(2))).unwrap();
        let focused_functions = focused[&target].abi_fuzzed_functions().collect::<Vec<_>>();

        assert_eq!(focused_functions.len(), 1);
        assert_eq!(focused_functions[0].selector(), third_selector);
    }

    #[test]
    fn invariant_focus_freezes_dynamic_target_updates() {
        let target = Address::repeat_byte(0x44);
        let first = function("first(uint256)");
        let second = function("second(uint256)");
        let mut contract = targeted_contract("Target", vec![first.clone(), second.clone()]);
        contract.targeted_functions = vec![first, second];

        let mut targeted_contracts = TargetedContracts::new();
        targeted_contracts.insert(target, contract);
        let campaign_seed = InvariantCampaignSeed {
            artifact_filters: ArtifactFilters::default(),
            sender_filters: SenderFilters::default(),
            targeted_contracts,
            targets_are_updatable: true,
            initial_handler_failures: Map::default(),
        };

        let normal_worker = campaign_seed_and_corpus_seed_for_worker(
            &campaign_seed,
            &WorkerCorpusSeed::default(),
            InvariantWorkerPlan { worker_id: 0, first_global_run: 0, runs: 1 },
            2,
            false,
            None,
        )
        .0;
        let focus_worker = campaign_seed_and_corpus_seed_for_worker(
            &campaign_seed,
            &WorkerCorpusSeed::default(),
            InvariantWorkerPlan { worker_id: 1, first_global_run: 1, runs: 1 },
            2,
            false,
            None,
        )
        .0;

        assert!(normal_worker.targets_are_updatable);
        assert!(!focus_worker.targets_are_updatable);
    }

    #[test]
    fn invariant_focus_does_not_widen_target_selectors() {
        let target = Address::repeat_byte(0x22);
        let allowed = function("allowed(uint256)");
        let hidden = function("hidden(uint256)");
        let mut contract = targeted_contract("Target", vec![allowed.clone(), hidden]);
        contract.targeted_functions = vec![allowed];

        let mut targets = TargetedContracts::new();
        targets.insert(target, contract);

        assert!(focused_targeted_contracts(&targets, 0, None).is_none());
    }

    #[test]
    fn invariant_focus_skips_excluded_selectors() {
        let target = Address::repeat_byte(0x33);
        let first = function("aaa(uint256)");
        let second = function("bbb(uint256)");
        let excluded = function("ccc(uint256)");
        let excluded_selector = excluded.selector();
        let mut contract = targeted_contract("Target", vec![first, second, excluded.clone()]);
        contract.excluded_functions = vec![excluded];

        let mut targets = TargetedContracts::new();
        targets.insert(target, contract);

        let focused = focused_targeted_contracts(&targets, 3, None).unwrap();
        let focused_functions = focused[&target].abi_fuzzed_functions().collect::<Vec<_>>();

        assert_eq!(focused_functions.len(), 1);
        assert_ne!(focused_functions[0].selector(), excluded_selector);
    }

    #[test]
    fn invariant_focus_skips_excluded_targeted_selectors() {
        let target = Address::repeat_byte(0x66);
        let first = function("aaa(uint256)");
        let second = function("bbb(uint256)");
        let excluded = function("ccc(uint256)");
        let excluded_selector = excluded.selector();
        let mut contract =
            targeted_contract("Target", vec![first.clone(), second.clone(), excluded.clone()]);
        contract.targeted_functions = vec![first, second, excluded.clone()];
        contract.excluded_functions = vec![excluded];

        let mut targets = TargetedContracts::new();
        targets.insert(target, contract);

        let focused = focused_targeted_contracts(&targets, 2, None).unwrap();
        let focused_functions = focused[&target].abi_fuzzed_functions().collect::<Vec<_>>();

        assert_eq!(focused_functions.len(), 1);
        assert_ne!(focused_functions[0].selector(), excluded_selector);
    }

    #[test]
    fn invariant_worker_cmp_log_selection_uses_one_worker_per_campaign() {
        use foundry_config::FuzzCorpusMutationWeights;

        let mut config = InvariantConfig::default();
        assert!(!invariant_worker_collects_evm_cmp_log(&config, 0, 1));

        config.corpus.corpus_dir = Some("corpus".into());
        assert!(invariant_worker_collects_evm_cmp_log(&config, 0, 1));
        assert!(invariant_worker_collects_evm_cmp_log(&config, 0, 4));
        assert!(!invariant_worker_collects_evm_cmp_log(&config, 1, 4));
        assert!(!invariant_worker_collects_evm_cmp_log(&config, 3, 4));

        config.corpus.mutation_weights = FuzzCorpusMutationWeights {
            mutation_weight_splice: 1,
            mutation_weight_repeat: 1,
            mutation_weight_interleave: 1,
            mutation_weight_prefix: 1,
            mutation_weight_suffix: 1,
            mutation_weight_abi: 1,
            mutation_weight_cmp: 0,
        };
        assert!(!invariant_worker_collects_evm_cmp_log(&config, 0, 1));

        // All-zero configured weights resolve to the default mutation distribution.
        config.corpus.mutation_weights = FuzzCorpusMutationWeights {
            mutation_weight_splice: 0,
            mutation_weight_repeat: 0,
            mutation_weight_interleave: 0,
            mutation_weight_prefix: 0,
            mutation_weight_suffix: 0,
            mutation_weight_abi: 0,
            mutation_weight_cmp: 0,
        };
        assert!(invariant_worker_collects_evm_cmp_log(&config, 0, 1));

        config.corpus.sancov_edges = true;
        assert!(!invariant_worker_collects_evm_cmp_log(&config, 0, 1));
        assert!(!invariant_worker_collects_evm_cmp_log(&config, 0, 4));
    }

    #[test]
    fn timed_invariant_workers_are_not_bounded_by_assigned_runs() {
        let plan = InvariantWorkerPlan { worker_id: 0, first_global_run: 0, runs: 1 };

        let untimed = InvariantCampaignState::new(EarlyExit::new(false), None);
        assert!(should_continue_invariant_worker(&untimed, 0, plan));
        assert!(!should_continue_invariant_worker(&untimed, 1, plan));

        let timed = InvariantCampaignState::new(EarlyExit::new(false), Some(60));
        assert!(should_continue_invariant_worker(&timed, 0, plan));
        assert!(should_continue_invariant_worker(&timed, 1, plan));
        assert!(should_continue_invariant_worker(&timed, 10_000, plan));
    }

    #[test]
    fn gas_report_samples_are_split_across_workers() {
        assert_eq!(gas_report_samples_for_worker(0, 0, 4), 0);
        assert_eq!(gas_report_samples_for_worker(8, 0, 4), 2);
        assert_eq!(gas_report_samples_for_worker(8, 3, 4), 2);
        assert_eq!(gas_report_samples_for_worker(10, 0, 4), 3);
        assert_eq!(gas_report_samples_for_worker(10, 1, 4), 3);
        assert_eq!(gas_report_samples_for_worker(10, 2, 4), 2);
        assert_eq!(gas_report_samples_for_worker(10, 3, 4), 2);
        assert_eq!(gas_report_samples_for_worker(3, 3, 4), 0);
    }

    #[test]
    fn invariant_progress_json_zero_elapsed_reports_zero_rates() {
        let throughput = InvariantThroughputMetrics { total_txs: 1, total_gas: 21_000 };

        let payload = build_invariant_progress_json(
            InvariantProgressContext {
                timestamp_secs: 456,
                contract_name: "invariant_zero_elapsed",
                optimization_best: None,
                throughput,
                elapsed: Duration::ZERO,
                worker_id: 0,
                worker_count: 1,
                time_since_new_edge: None,
            },
            &json!({ "corpus_count": 1 }),
            &InvariantFailureMetrics::default(),
        );

        assert_eq!(payload["tps"], json!(0.0));
        assert_eq!(payload["gps"], json!(0.0));
        assert!(payload.get("optimization_best").is_none());
        // No edge seen yet -> `null`.
        assert_eq!(payload["worker"]["secs_since_new_edge"], json!(null));
    }

    #[test]
    fn invariant_progress_json_reports_secs_since_new_edge() {
        let payload = build_invariant_progress_json(
            InvariantProgressContext {
                timestamp_secs: 1,
                contract_name: "TestContract",
                optimization_best: None,
                throughput: InvariantThroughputMetrics::default(),
                elapsed: Duration::from_secs(1),
                worker_id: 2,
                worker_count: 4,
                time_since_new_edge: Some(Duration::from_millis(1500)),
            },
            &json!({ "corpus_count": 1 }),
            &InvariantFailureMetrics::default(),
        );

        assert_eq!(payload["worker"]["id"], json!(2));
        assert_eq!(payload["worker"]["secs_since_new_edge"], json!(1.5));
    }

    #[test]
    fn invariant_progress_json_rounds_fractional_rates() {
        let payload = build_invariant_progress_json(
            InvariantProgressContext {
                timestamp_secs: 456,
                contract_name: "TestContract",
                optimization_best: None,
                throughput: InvariantThroughputMetrics { total_txs: 1, total_gas: 1 },
                elapsed: Duration::from_secs(3),
                worker_id: 0,
                worker_count: 1,
                time_since_new_edge: None,
            },
            &json!({ "corpus_count": 1 }),
            &InvariantFailureMetrics::default(),
        );

        assert_eq!(payload["tps"], json!(0.33));
        assert_eq!(payload["gps"], json!(0.33));
    }

    #[test]
    fn invariant_progress_json_includes_broken_counts() {
        let mut failure_metrics = InvariantFailureMetrics::default();
        failure_metrics.record_failure("invariant_a", "TestContract", "revert");
        failure_metrics.record_failure("invariant_a", "TestContract", "revert");
        failure_metrics.record_failure("invariant_b", "TestContract", "assertion failed");
        failure_metrics.broken_handlers = 7;

        let payload = build_invariant_progress_json(
            InvariantProgressContext {
                timestamp_secs: 789,
                contract_name: "TestContract",
                optimization_best: None,
                throughput: InvariantThroughputMetrics::default(),
                elapsed: Duration::from_secs(1),
                worker_id: 0,
                worker_count: 1,
                time_since_new_edge: None,
            },
            &json!({ "corpus_count": 5 }),
            &failure_metrics,
        );

        assert!(payload["metrics"].get("failures").is_none());
        assert!(payload["metrics"].get("unique_failures").is_none());
        assert_eq!(payload["metrics"]["broken_invariants"], json!(2));
        assert_eq!(payload["metrics"]["broken_assertions"], json!(7));
        assert!(payload["metrics"].get("broken_handlers").is_none());
    }

    #[test]
    fn handler_assertion_failure_event_includes_site_and_reason() {
        let target = Address::repeat_byte(0x11);
        let selector = Selector::from([0xde, 0xad, 0xbe, 0xef]);

        assert_eq!(
            build_handler_failure_event(123, target, selector, "assertion failed"),
            json!({
                "timestamp": 123,
                "event": "failure",
                "failure_type": "handler_assertion",
                "target": target,
                "selector": "0xdeadbeef",
                "reason": "assertion failed",
            })
        );
    }

    #[test]
    fn failure_metrics_tracks_total_and_unique_failures() {
        let mut metrics = InvariantFailureMetrics::default();
        metrics.record_failure("invariant_a", "TestContract", "revert");
        metrics.record_failure("invariant_a", "TestContract", "revert");
        metrics.record_failure("invariant_b", "TestContract", "assertion failed");

        assert_eq!(metrics.failures, 3);
        assert_eq!(metrics.unique_failures.len(), 2);
        assert!(metrics.unique_failures.contains("invariant_a"));
        assert!(metrics.unique_failures.contains("invariant_b"));
    }

    #[test]
    fn failure_metrics_default_is_zero() {
        let metrics = InvariantFailureMetrics::default();
        assert_eq!(metrics.failures, 0);
        assert!(metrics.unique_failures.is_empty());
        assert_eq!(metrics.broken_handlers, 0);
    }
}