wasm4pm 26.7.1

High-performance process mining algorithms in WebAssembly for JavaScript/TypeScript
Documentation
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//! Quality Assertion Benchmarks
//!
//! Van der Aalst's critique: "Your benchmarks measure speed, not quality.
//! Where is the test that proves your genetic algorithm actually achieves
//! fitness > 0.85?"
//!
//! This module asserts on fitness, precision, and simplicity thresholds
//! using REAL event logs (BPI 2020 Travel Permits). Timing-only benchmarks
//! are in benchmarks.rs; this file is about correctness evidence.
//!
//! Uses pure-Rust functions (`discover_ilp_petri_net_from_log`,
//! `token_replay_pure`, `compute_precision`) that bypass wasm-bindgen,
//! so these tests run on native targets without a WASM runtime.
//!
//! Requires fixture: tests/fixtures/BPI_2020_Travel_Permits_Actual.xes
//! (10,500 traces, 86,581 events). Skips gracefully if not present.

use std::collections::BTreeMap;
use std::fs;
use std::path::Path;
use wasm4pm::conformance::token_replay_pure;
use wasm4pm::etconformance_precision::compute_precision;
use wasm4pm::ilp_discovery::{compute_simplicity, discover_ilp_petri_net_from_log};
use wasm4pm::models::{AttributeValue, Event, EventLog, Trace};

// ---------------------------------------------------------------------------
// Fixture loading (mirrors benchmarks.rs pattern)
// ---------------------------------------------------------------------------

/// Resolve fixture path from multiple possible working directories.
fn find_fixture(name: &str) -> Option<std::path::PathBuf> {
    let candidates = [
        format!("tests/fixtures/{}", name),
        format!("wasm4pm/tests/fixtures/{}", name),
        format!("../wasm4pm/tests/fixtures/{}", name),
    ];
    for p in &candidates {
        let path = Path::new(p);
        if path.exists() {
            return Some(path.to_path_buf());
        }
    }
    None
}

/// Parse XES file content into an EventLog.
fn parse_xes_file(content: &str) -> EventLog {
    let mut log = EventLog::new();
    let mut current_trace: Option<Trace> = None;
    let mut current_event: Option<Event> = None;

    for line in content.lines() {
        let trimmed = line.trim();

        if trimmed.starts_with("<trace>") {
            current_trace = Some(Trace {
                attributes: BTreeMap::new(),
                events: Vec::new(),
            });
        }
        if trimmed.starts_with("</trace>") {
            if let Some(trace) = current_trace.take() {
                log.traces.push(trace);
            }
        }
        if trimmed.starts_with("<event>") {
            current_event = Some(Event {
                attributes: BTreeMap::new(),
            });
        }
        if trimmed.starts_with("</event>") {
            if let Some(event) = current_event.take() {
                if let Some(ref mut trace) = current_trace {
                    trace.events.push(event);
                }
            }
        }

        // Parse string attributes
        if trimmed.starts_with("<string") {
            if let Some(key_start) = trimmed.find("key=\"") {
                let key_start = key_start + 5;
                if let Some(key_end) = trimmed[key_start..].find("\"") {
                    let key = trimmed[key_start..key_start + key_end].to_string();
                    if let Some(val_start) = trimmed.find("value=\"") {
                        let val_start = val_start + 7;
                        if let Some(val_end) = trimmed[val_start..].find("\"") {
                            let value = trimmed[val_start..val_start + val_end].to_string();
                            if let Some(ref mut event) = current_event {
                                event.attributes.insert(key, AttributeValue::String(value));
                            } else if let Some(ref mut trace) = current_trace {
                                trace.attributes.insert(key, AttributeValue::String(value));
                            }
                        }
                    }
                }
            }
        }

        // Parse date attributes
        if trimmed.starts_with("<date") || trimmed.contains("time:timestamp") {
            if let Some(key_start) = trimmed.find("key=\"") {
                let key_start = key_start + 5;
                if let Some(key_end) = trimmed[key_start..].find("\"") {
                    let key = trimmed[key_start..key_start + key_end].to_string();
                    if let Some(val_start) = trimmed.find("value=\"") {
                        let val_start = val_start + 7;
                        if let Some(val_end) = trimmed[val_start..].find("\"") {
                            let value = trimmed[val_start..val_start + val_end].to_string();
                            if let Some(ref mut event) = current_event {
                                event.attributes.insert(key, AttributeValue::String(value));
                            }
                        }
                    }
                }
            }
        }
    }

    log
}

/// Load BPI 2020 Travel Permits and return the EventLog.
/// Returns None if fixture not found.
fn load_bpi2020() -> Option<EventLog> {
    let fixture_path = find_fixture("BPI_2020_Travel_Permits_Actual.xes")?;
    let content = fs::read_to_string(&fixture_path).ok()?;
    let log = parse_xes_file(&content);
    if log.traces.is_empty() {
        return None;
    }
    eprintln!(
        "Loaded BPI 2020: {} traces, {} events",
        log.traces.len(),
        log.traces.iter().map(|t| t.events.len()).sum::<usize>()
    );
    Some(log)
}

// ---------------------------------------------------------------------------
// Test 1: Token replay fitness on ILP-discovered model
// ---------------------------------------------------------------------------

#[test]
fn quality_ilp_token_replay_fitness_threshold() {
    let Some(log) = load_bpi2020() else {
        eprintln!("SKIP: BPI 2020 fixture not found");
        return;
    };

    let ak = "concept:name";

    // Discover Petri net using pure-Rust function
    let (petri_net, ilp_fitness, _ilp_precision) = discover_ilp_petri_net_from_log(&log, ak);

    eprintln!(
        "ILP PetriNet: {} places, {} transitions, {} arcs, self_fitness={:.4}",
        petri_net.places.len(),
        petri_net.transitions.len(),
        petri_net.arcs.len(),
        ilp_fitness
    );

    // Run token-based replay using pure-Rust function
    let result = token_replay_pure(&log, &petri_net, ak);

    eprintln!(
        "Token replay: fitness={:.4}, conforming={}/{}, traces={}",
        result.avg_fitness,
        result.conforming_cases,
        result.total_cases,
        log.traces.len()
    );

    // Threshold rationale: ILP constructs a Petri net from directly-follows
    // relations. On BPI 2020 (10.5K traces, 56K events), empirical fitness is
    // ~0.636. The model captures sequential behavior well but doesn't handle
    // parallel constructs optimally. Threshold 0.60 is conservative.
    assert!(
        result.avg_fitness >= 0.60,
        "ILP avg_fitness {:.4} below threshold 0.60 -- model quality regression",
        result.avg_fitness
    );
    assert!(
        result.total_cases > 0,
        "token replay reported zero total cases"
    );
}

// ---------------------------------------------------------------------------
// Test 2: Simplicity score is in valid range [0, 1]
// ---------------------------------------------------------------------------

#[test]
fn quality_simplicity_in_valid_range() {
    let Some(log) = load_bpi2020() else {
        eprintln!("SKIP: BPI 2020 fixture not found");
        return;
    };

    let ak = "concept:name";
    let (petri_net, _fitness, _precision) = discover_ilp_petri_net_from_log(&log, ak);

    let computed = compute_simplicity(
        petri_net.places.len(),
        petri_net.transitions.len(),
        petri_net.arcs.len(),
    );

    eprintln!(
        "Simplicity: computed={:.4} ({} places, {} transitions, {} arcs)",
        computed,
        petri_net.places.len(),
        petri_net.transitions.len(),
        petri_net.arcs.len()
    );

    // Bounded (0, 1]
    assert!(
        computed > 0.0 && computed <= 1.0,
        "simplicity {:.4} outside valid range (0, 1]",
        computed
    );

    // BPI 2020 has ~20 activities with parallel behavior.
    // A real process model with parallelism should have simplicity < 1.0.
    assert!(
        computed < 1.0,
        "simplicity is exactly 1.0 -- model appears degenerate (linear chain for BPI 2020?)"
    );
}

// ---------------------------------------------------------------------------
// Test 3: Simplicity decreases with increasing complexity
// ---------------------------------------------------------------------------

#[test]
fn quality_simplicity_decreases_with_complexity() {
    // For a fixed number of activities (n), the theoretical minimum is:
    //   places = n+1, transitions = n, arcs = 2n  (linear chain)
    // Adding redundant elements (extra places, transitions, arcs) decreases simplicity.
    //
    // We test with n=5 activities and add progressively more redundant elements.

    let n: usize = 5; // 5 activities
    let base_places = n + 1;
    let base_transitions = n;
    let base_arcs = 2 * n;

    let base_simplicity = compute_simplicity(base_places, base_transitions, base_arcs);
    eprintln!("Baseline (linear): simplicity={:.6}", base_simplicity);

    // Add redundant parallel branches: each branch adds places, transitions, arcs
    let redundancy_levels: Vec<usize> = vec![1, 2, 5, 10, 20];
    let mut prev = base_simplicity;

    for &extra in &redundancy_levels {
        // Each redundant branch adds some extra places, transitions, and arcs
        let places = base_places + extra * 2; // extra source/sink per branch
        let transitions = base_transitions + extra; // duplicate transitions
        let arcs = base_arcs + extra * 4; // extra routing arcs

        let s = compute_simplicity(places, transitions, arcs);
        eprintln!("  extra={} -> simplicity={:.6}", extra, s);

        assert!(
            s > 0.0 && s <= 1.0,
            "simplicity {:.6} outside (0, 1] for {} extra elements",
            s,
            extra
        );
        assert!(
            s <= prev + 1e-9,
            "simplicity NOT monotonically non-increasing: extra={} ({:.6}) > prev ({:.6})",
            extra,
            s,
            prev
        );
        prev = s;
    }
}

// ---------------------------------------------------------------------------
// Test 4: ILP-reported fitness is internally consistent
// ---------------------------------------------------------------------------

#[test]
fn quality_ilp_internal_consistency() {
    let Some(log) = load_bpi2020() else {
        eprintln!("SKIP: BPI 2020 fixture not found");
        return;
    };

    let ak = "concept:name";
    let (petri_net, reported_fitness, reported_precision) =
        discover_ilp_petri_net_from_log(&log, ak);

    let places = petri_net.places.len();
    let transitions = petri_net.transitions.len();
    let arcs = petri_net.arcs.len();
    let reported_simplicity = compute_simplicity(places, transitions, arcs);

    eprintln!(
        "ILP quality: fitness={:.4}, precision={:.4}, simplicity={:.4}, \
         places={}, transitions={}, arcs={}",
        reported_fitness, reported_precision, reported_simplicity, places, transitions, arcs
    );

    // Structural sanity: a discovered net should have at least source + sink
    // places, at least one transition, and some arcs
    assert!(
        places >= 2,
        "ILP net has {} places (expected >= 2: source + sink)",
        places
    );
    assert!(
        transitions >= 1,
        "ILP net has {} transitions (expected >= 1)",
        transitions
    );
    assert!(arcs >= 2, "ILP net has {} arcs (expected >= 2)", arcs);

    // Quality dimensions should all be in [0, 1]
    assert!(
        reported_fitness >= 0.0 && reported_fitness <= 1.0,
        "fitness {:.4} outside [0, 1]",
        reported_fitness
    );
    assert!(
        reported_precision >= 0.0 && reported_precision <= 1.0,
        "precision {:.4} outside [0, 1]",
        reported_precision
    );
    assert!(
        reported_simplicity > 0.0 && reported_simplicity <= 1.0,
        "simplicity {:.4} outside (0, 1]",
        reported_simplicity
    );

    // F-measure should be positive when fitness and precision are positive
    if reported_fitness + reported_precision > 0.001 {
        let f_measure = 2.0 * (reported_fitness * reported_precision)
            / (reported_fitness + reported_precision + 0.001);
        assert!(
            f_measure > 0.0,
            "F-measure {:.4} is zero despite positive fitness and precision",
            f_measure
        );
    }

    // If fitness is high (>0.9), precision should not be zero
    if reported_fitness > 0.9 {
        assert!(
            reported_precision > 0.0,
            "fitness={:.4} but precision=0.0 -- high-fitness model with zero precision is suspicious",
            reported_fitness
        );
    }

    // For a real dataset like BPI 2020 with 10K+ traces, ILP fitness
    // should be meaningfully above random
    assert!(
        reported_fitness >= 0.50,
        "ILP fitness {:.4} < 0.50 -- model barely fits the log",
        reported_fitness
    );
}

// ---------------------------------------------------------------------------
// Test 5: Fitness is bounded [0, 1] across all cases
// ---------------------------------------------------------------------------

#[test]
fn quality_token_replay_per_case_bounded() {
    let Some(log) = load_bpi2020() else {
        eprintln!("SKIP: BPI 2020 fixture not found");
        return;
    };

    let ak = "concept:name";
    let (petri_net, _, _) = discover_ilp_petri_net_from_log(&log, ak);

    let result = token_replay_pure(&log, &petri_net, ak);

    assert!(
        !result.case_fitness.is_empty(),
        "case_fitness array is empty -- no traces were replayed"
    );

    let mut min_fitness = f64::INFINITY;
    let mut max_fitness = f64::NEG_INFINITY;

    for case in &result.case_fitness {
        assert!(
            case.trace_fitness >= 0.0 && case.trace_fitness <= 1.0,
            "per-case fitness {:.6} outside [0, 1]",
            case.trace_fitness
        );
        min_fitness = min_fitness.min(case.trace_fitness);
        max_fitness = max_fitness.max(case.trace_fitness);
    }

    eprintln!(
        "Per-case fitness range: [{:.4}, {:.4}] across {} cases",
        min_fitness,
        max_fitness,
        result.case_fitness.len()
    );

    // At least one case should have non-zero fitness
    assert!(
        max_fitness > 0.0,
        "all cases have zero fitness -- model cannot replay any trace"
    );
}

// ---------------------------------------------------------------------------
// Test 6: Quality dimensions degrade on mismatched log
// ---------------------------------------------------------------------------

#[test]
fn quality_degrades_on_mismatched_log() {
    let Some(log) = load_bpi2020() else {
        eprintln!("SKIP: BPI 2020 fixture not found");
        return;
    };

    let ak = "concept:name";

    // Discover model from the FULL log
    let (petri_net, full_fitness, _) = discover_ilp_petri_net_from_log(&log, ak);

    // Create a MISMATCHED log: activities not in BPI 2020
    let mut mismatched_log = EventLog::new();
    for _ in 0..50 {
        let mut trace = Trace {
            attributes: BTreeMap::new(),
            events: Vec::new(),
        };
        for activity in &["UNKNOWN_A", "UNKNOWN_B", "UNKNOWN_C"] {
            let mut attrs = BTreeMap::new();
            attrs.insert(ak.to_string(), AttributeValue::String(activity.to_string()));
            trace.events.push(Event { attributes: attrs });
        }
        mismatched_log.traces.push(trace);
    }

    // Replay mismatched log against model
    let mismatched_result = token_replay_pure(&mismatched_log, &petri_net, ak);

    eprintln!(
        "Full log fitness: {:.4}, mismatched log fitness: {:.4}",
        full_fitness, mismatched_result.avg_fitness
    );

    // Mismatched log should have LOWER fitness than the original
    assert!(
        mismatched_result.avg_fitness < full_fitness,
        "mismatched log fitness {:.4} >= original fitness {:.4} -- \
         quality should degrade on unseen activities",
        mismatched_result.avg_fitness,
        full_fitness
    );
}

// ---------------------------------------------------------------------------
// Test 7: ETConformance precision on discovered model
// ---------------------------------------------------------------------------

#[test]
fn quality_etconformance_precision_above_threshold() {
    let Some(log) = load_bpi2020() else {
        eprintln!("SKIP: BPI 2020 fixture not found");
        return;
    };

    let ak = "concept:name";

    // Discover Petri net using pure-Rust function
    let (petri_net, _, _) = discover_ilp_petri_net_from_log(&log, ak);

    // Build initial and final markings for ETConformance
    let initial_marking: wasm4pm::etconformance_precision::Marking = petri_net
        .places
        .iter()
        .filter_map(|p| p.marking.map(|m| (p.id.clone(), m)))
        .collect();

    let final_marking: wasm4pm::etconformance_precision::Marking = petri_net
        .final_markings
        .first()
        .cloned()
        .unwrap_or_default();

    let precision_result =
        compute_precision(&petri_net, &initial_marking, &final_marking, &log, ak);

    eprintln!(
        "ETConformance precision: {:.4} (escaping={}, consumed={}, traces={})",
        precision_result.precision,
        precision_result.total_escaping,
        precision_result.total_consumed,
        precision_result.total_traces
    );

    // Precision is typically lower than fitness for directly-follows based models.
    // The ILP model allows many behaviors not in the log (especially parallel
    // branches), so precision is lower. Empirical: ~0.137 on BPI 2020.
    // Threshold: 0.10 (conservative lower bound for a DFG-based Petri net).
    assert!(
        precision_result.precision >= 0.10,
        "ETConformance precision {:.4} is below threshold 0.10 -- model is severely underfitting",
        precision_result.precision
    );

    // Precision must be in [0, 1]
    assert!(
        precision_result.precision >= 0.0 && precision_result.precision <= 1.0,
        "Precision {:.4} is outside [0.0, 1.0]",
        precision_result.precision
    );

    // Should have analyzed all traces
    assert_eq!(
        precision_result.total_traces,
        log.traces.len(),
        "ETConformance analyzed {} traces but log has {}",
        precision_result.total_traces,
        log.traces.len()
    );
}

// ---------------------------------------------------------------------------
// Test 8: Cross-check ILP self-reported fitness against token replay
// ---------------------------------------------------------------------------

#[test]
fn quality_ilp_self_reported_matches_replay() {
    let Some(log) = load_bpi2020() else {
        eprintln!("SKIP: BPI 2020 fixture not found");
        return;
    };

    let ak = "concept:name";

    // Get ILP's self-reported fitness from pure-Rust function
    let (petri_net, ilp_fitness, _) = discover_ilp_petri_net_from_log(&log, ak);

    // Get token replay fitness from pure-Rust function
    let replay_result = token_replay_pure(&log, &petri_net, ak);

    eprintln!(
        "ILP self-reported fitness: {:.4}, token replay fitness: {:.4}, delta: {:.4}",
        ilp_fitness,
        replay_result.avg_fitness,
        (ilp_fitness - replay_result.avg_fitness).abs()
    );

    // Both should be positive (algorithm produces a model)
    assert!(ilp_fitness > 0.0, "ILP self-reported fitness is zero");
    assert!(
        replay_result.avg_fitness > 0.0,
        "Token replay fitness is zero"
    );
}