Manifest-drive layered admissibility curve fixture ordering

artifacts/layered_admissibility_results.json

@@ -61,7 +61,7 @@
       "governance_score": 1.0,
       "observed_admissible": false,
       "operational_score": 1.0,
-      "overall_admissibility_score": 0.8333333333333333,
+      "overall_admissibility_score": 0.8333333333333334,
       "passed_contracts": [
         "no_orphan_tool_calls",
         "pre_merge_review"

src/validation/admissibility_scorer.py

@@ -1,6 +1,7 @@
 from __future__ import annotations
 
 from dataclasses import dataclass
+from fractions import Fraction
 
 from src.validation.contract_validator import Layer, ValidationResult
 
@@ -47,15 +48,18 @@ def score(self, results: list[ValidationResult], expected_admissible: bool | Non
 
         layer_scores: list[LayerScore] = []
         score_by_layer: dict[Layer, float] = {}
+        score_fraction_by_layer: dict[Layer, Fraction] = {}
 
         for layer in self._LAYER_ORDER:
             layer_results = [result for result in results if result.layer == layer]
             passed_in_layer = tuple(sorted(result.contract_id for result in layer_results if result.passed))
             failed_in_layer = tuple(sorted(result.contract_id for result in layer_results if not result.passed))
             labels_in_layer = tuple(sorted({result.failure_label for result in layer_results if result.failure_label is not None}))
             total_contracts = len(layer_results)
-            layer_score = 1.0 if total_contracts == 0 else len(passed_in_layer) / total_contracts
+            layer_score_fraction = Fraction(1, 1) if total_contracts == 0 else Fraction(len(passed_in_layer), total_contracts)
+            layer_score = float(layer_score_fraction)
             score_by_layer[layer] = layer_score
+            score_fraction_by_layer[layer] = layer_score_fraction
             layer_scores.append(
                 LayerScore(
                     layer=layer,
@@ -66,7 +70,8 @@ def score(self, results: list[ValidationResult], expected_admissible: bool | Non
                 )
             )
 
-        overall_admissibility_score = sum(score_by_layer[layer] for layer in self._LAYER_ORDER) / len(self._LAYER_ORDER)
+        overall_score_fraction = sum(score_fraction_by_layer[layer] for layer in self._LAYER_ORDER) / len(self._LAYER_ORDER)
+        overall_admissibility_score = float(overall_score_fraction)
 
         return AdmissibilityScore(
             structural_score=score_by_layer[Layer.STRUCTURAL],

src/validation/degradation_curve_generator.py

@@ -9,6 +9,11 @@
 from src.validation.contract_validator import ContractValidator
 
 
+MANIFEST_PATH = Path("fixtures/manifest.json")
+LAYERED_CURVE_FAMILY = "coding_workflow_pr_review"
+LAYERED_CURVE_LEVELS = ("baseline", "mild", "moderate", "severe")
+
+
 @dataclass(frozen=True, slots=True)
 class FixtureScorePoint:
     fixture_id: str
@@ -106,7 +111,33 @@ def evaluate_fixture(self, fixture_path: Path) -> FixtureScorePoint:
             failure_labels=tuple(sorted(score.failure_labels)),
         )
 
-    def generate(self, fixtures: list[Path], curve_id: str) -> DegradationCurve:
+    def _load_fixture_manifest(self, manifest_path: Path = MANIFEST_PATH) -> tuple[dict[str, Any], ...]:
+        manifest = self._load_json(manifest_path)
+        fixtures = manifest.get("fixtures")
+        if not isinstance(fixtures, list):
+            raise ValueError(f"invalid fixture manifest format: {manifest_path}")
+        return tuple(fixtures)
+
+    def fixtures_for_layered_admissibility_curve(self, manifest_path: Path = MANIFEST_PATH) -> tuple[Path, ...]:
+        level_to_path: dict[str, Path] = {}
+
+        for entry in self._load_fixture_manifest(manifest_path):
+            if entry.get("family") != LAYERED_CURVE_FAMILY:
+                continue
+            level = entry.get("degradation_level")
+            if level in LAYERED_CURVE_LEVELS:
+                path_str = entry.get("path")
+                if not path_str:
+                    raise ValueError(f"missing path for fixture in manifest: {entry.get('fixture_id')}")
+                level_to_path[str(level)] = Path(path_str)
+
+        missing_levels = [level for level in LAYERED_CURVE_LEVELS if level not in level_to_path]
+        if missing_levels:
+            raise ValueError(f"missing layered admissibility fixtures for levels: {missing_levels}")
+
+        return tuple(level_to_path[level] for level in LAYERED_CURVE_LEVELS)
+
+    def generate(self, fixtures: list[Path] | tuple[Path, ...], curve_id: str) -> DegradationCurve:
         points = tuple(self.evaluate_fixture(path) for path in fixtures)
         return DegradationCurve(curve_id=curve_id, version=self.VERSION, generated_by=self.__class__.__name__, points=points)
 

tests/test_degradation_curve_generator.py

@@ -40,15 +40,26 @@ def test_evaluate_negative_fixture_detects_expected_failures() -> None:
 
 def test_generate_curve_is_deterministic() -> None:
     generator = DegradationCurveGenerator()
-    fixtures = [POS_FIXTURE, MILD_FIXTURE, MODERATE_FIXTURE, NEG_FIXTURE]
+    fixtures = generator.fixtures_for_layered_admissibility_curve()
     assert generator.to_dict(generator.generate(fixtures, curve_id=CURVE_ID)) == generator.to_dict(
         generator.generate(fixtures, curve_id=CURVE_ID)
     )
 
 
+
+
+def test_layered_curve_fixtures_are_loaded_from_manifest_order() -> None:
+    fixtures = DegradationCurveGenerator().fixtures_for_layered_admissibility_curve()
+    assert [fixture.as_posix() for fixture in fixtures] == [
+        POS_FIXTURE.as_posix(),
+        MILD_FIXTURE.as_posix(),
+        MODERATE_FIXTURE.as_posix(),
+        NEG_FIXTURE.as_posix(),
+    ]
+
 def test_to_dict_is_json_compatible_and_sorted() -> None:
     generator = DegradationCurveGenerator()
-    curve = generator.generate([POS_FIXTURE, MILD_FIXTURE, MODERATE_FIXTURE, NEG_FIXTURE], curve_id=CURVE_ID)
+    curve = generator.generate(generator.fixtures_for_layered_admissibility_curve(), curve_id=CURVE_ID)
     curve_dict = generator.to_dict(curve)
     json.dumps(curve_dict, sort_keys=True)
     assert [point["fixture_path"] for point in curve_dict["points"]] == [
@@ -61,7 +72,7 @@ def test_to_dict_is_json_compatible_and_sorted() -> None:
 
 def test_write_json_matches_committed_artifact(tmp_path: Path) -> None:
     generator = DegradationCurveGenerator()
-    curve = generator.generate([POS_FIXTURE, MILD_FIXTURE, MODERATE_FIXTURE, NEG_FIXTURE], curve_id=CURVE_ID)
+    curve = generator.generate(generator.fixtures_for_layered_admissibility_curve(), curve_id=CURVE_ID)
     generated_path = tmp_path / "layered_admissibility_results.json"
     generator.write_json(curve, generated_path)
 
@@ -72,7 +83,7 @@ def test_write_json_matches_committed_artifact(tmp_path: Path) -> None:
 
 def test_write_markdown_contains_fixture_rows(tmp_path: Path) -> None:
     generator = DegradationCurveGenerator()
-    curve = generator.generate([POS_FIXTURE, MILD_FIXTURE, MODERATE_FIXTURE, NEG_FIXTURE], curve_id=CURVE_ID)
+    curve = generator.generate(generator.fixtures_for_layered_admissibility_curve(), curve_id=CURVE_ID)
     markdown_path = tmp_path / "layered_admissibility.md"
     generator.write_markdown(curve, markdown_path)
 
@@ -116,7 +127,7 @@ def test_disallowed_failure_label_raises_clear_error() -> None:
 
 def test_progressive_curve_scores_are_monotonic_or_non_increasing() -> None:
     generator = DegradationCurveGenerator()
-    curve = generator.generate([POS_FIXTURE, MILD_FIXTURE, MODERATE_FIXTURE, NEG_FIXTURE], curve_id=CURVE_ID)
+    curve = generator.generate(generator.fixtures_for_layered_admissibility_curve(), curve_id=CURVE_ID)
     points = {point.fixture_id: point for point in curve.points}
 
     assert points["coding_workflow_pr_review_v1"].overall_admissibility_score == 1.0