mnemosyne/tests/test_entropy.py

"""Tests for the entropy-gated faulting module.

Tests the EntropyDetector's ability to detect hedging, uncertainty,
evicted entity references, and the should_fault decision logic.
"""

from __future__ import annotations

from mnemosyne.entropy import (
    DEFAULT_FAULT_THRESHOLD,
    EntropyDetector,
    EntropySignal,
)


# ── Hedging detection ────────────────────────────────────────────────────


def test_entropy_hedging_detected():
    """Hedging language like 'I think' and 'probably' is detected."""
    detector = EntropyDetector()
    signal = detector.analyze_response(
        "I think the function is probably in utils.py",
        evicted_entities=[],
    )
    assert signal.has_hedging is True
    assert signal.score > 0


def test_entropy_multiple_patterns():
    """Multiple hedging patterns increase the score."""
    detector = EntropyDetector()
    signal_one = detector.analyze_response(
        "I think it might work.",
        evicted_entities=[],
    )
    signal_many = detector.analyze_response(
        "I think it probably might be in the file, if I recall correctly. I believe so.",
        evicted_entities=[],
    )
    assert signal_many.score >= signal_one.score


# ── Uncertainty detection ────────────────────────────────────────────────


def test_entropy_uncertainty_detected():
    """Explicit uncertainty like 'I'm not sure' is detected."""
    detector = EntropyDetector()
    signal = detector.analyze_response(
        "I'm not sure about the exact implementation. It's unclear to me.",
        evicted_entities=[],
    )
    assert signal.has_uncertainty is True
    assert signal.score > 0


# ── No signals ───────────────────────────────────────────────────────────


def test_entropy_no_signals():
    """Clean, confident response has no entropy signals."""
    detector = EntropyDetector()
    signal = detector.analyze_response(
        "The function `calculate_total` is defined in src/utils.py at line 42. "
        "It takes two arguments: price and quantity.",
        evicted_entities=[],
    )
    assert signal.has_hedging is False
    assert signal.has_uncertainty is False
    assert signal.references_evicted is False
    assert signal.has_hallucination_risk is False
    assert signal.score == 0.0


# ── Evicted entity references ───────────────────────────────────────────


def test_entropy_evicted_references():
    """References to evicted entities are detected."""
    detector = EntropyDetector()
    signal = detector.analyze_response(
        "The config is in settings.py and the handler is in views.py",
        evicted_entities=["settings.py", "views.py", "models.py"],
    )
    assert signal.references_evicted is True
    assert "settings.py" in signal.referenced_entities
    assert "views.py" in signal.referenced_entities
    assert "models.py" not in signal.referenced_entities


def test_entropy_hallucination_risk():
    """Hedging + evicted references = hallucination risk."""
    detector = EntropyDetector()
    signal = detector.analyze_response(
        "I think the config is probably in settings.py somewhere",
        evicted_entities=["settings.py"],
    )
    assert signal.has_hedging is True
    assert signal.references_evicted is True
    assert signal.has_hallucination_risk is True
    # Hallucination risk adds a bonus to the score
    assert signal.score > 0.3


# ── Composite score ──────────────────────────────────────────────────────


def test_entropy_composite_score():
    """Score combines hedging, uncertainty, and evicted references."""
    detector = EntropyDetector()
    # All signals present
    signal = detector.analyze_response(
        "I'm not sure, but I think the code is probably in utils.py",
        evicted_entities=["utils.py"],
    )
    assert signal.has_hedging is True
    assert signal.has_uncertainty is True
    assert signal.references_evicted is True
    assert signal.score > 0.5  # Should be high with all signals


# ── should_fault decisions ───────────────────────────────────────────────


def test_entropy_should_fault_above_threshold():
    """Faulting triggers when score >= threshold AND references evicted."""
    detector = EntropyDetector(fault_threshold=0.4)
    signal = detector.analyze_response(
        "I think the code is probably in utils.py, if I recall correctly. I believe so.",
        evicted_entities=["utils.py"],
    )
    # Score should be above 0.4 with hedging + evicted ref + hallucination bonus
    entities = detector.should_fault(signal)
    assert len(entities) > 0
    assert "utils.py" in entities


def test_entropy_should_fault_below_threshold():
    """No faulting when score is below threshold."""
    detector = EntropyDetector(fault_threshold=0.99)  # Very high threshold
    signal = detector.analyze_response(
        "I think it might be there.",
        evicted_entities=[],
    )
    entities = detector.should_fault(signal)
    assert entities == []


def test_entropy_should_fault_no_evicted_refs():
    """No faulting when there are no evicted entity references, even with high hedging."""
    detector = EntropyDetector(fault_threshold=0.1)  # Very low threshold
    signal = detector.analyze_response(
        "I think it probably might be somewhere, if I recall. I believe so.",
        evicted_entities=[],
    )
    # Even though hedging score is high, no evicted refs → no fault
    entities = detector.should_fault(signal)
    assert entities == []


# ── Stats tracking ───────────────────────────────────────────────────────


def test_entropy_stats_tracking():
    """Stats correctly count analyzed responses and triggered faults."""
    detector = EntropyDetector(fault_threshold=0.3)
    assert detector.stats == {"analyzed": 0, "faults_triggered": 0}

    # Analyze a clean response
    detector.analyze_response("The function is in utils.py.", evicted_entities=[])
    assert detector.stats["analyzed"] == 1
    assert detector.stats["faults_triggered"] == 0

    # Analyze and fault a hedging response with evicted refs
    signal = detector.analyze_response(
        "I think the code is probably in utils.py, if I recall correctly. I believe so.",
        evicted_entities=["utils.py"],
    )
    assert detector.stats["analyzed"] == 2
    detector.should_fault(signal)
    assert detector.stats["faults_triggered"] == 1