fix(transparency): compute visualiser semantic capability lazily; give registry-less test stubs a registry (refs #318)

Author: stanlrt

src/raitap/transparency/explainers/tests/test_base_explainer.py

@@ -26,9 +26,19 @@
 )
 from raitap.transparency.explainers.base_explainer import AttributionOnlyExplainer
 
+# Method-family resolution reads each adapter's own ``algorithm_registry``
+# ClassVar (issue #318). Bare test stubs declare this shared minimal registry
+# so ``method_families_for_explainer`` resolves them the same way a real
+# decorated adapter is resolved.
+_BASE_REGISTRY: Mapping[str, ExplainerAlgorithmSpec] = {
+    "Saliency": ExplainerAlgorithmSpec({MethodFamily.GRADIENT}),
+    "IntegratedGradients": ExplainerAlgorithmSpec({MethodFamily.GRADIENT}),
+}
+
 
 class _StrictExplainer(AttributionOnlyExplainer):
     algorithm = "Saliency"
+    algorithm_registry = _BASE_REGISTRY
 
     def __init__(self) -> None:
         super().__init__()
@@ -70,6 +80,7 @@ def compute_attributions(
 
 class _BatchRecordingExplainer(AttributionOnlyExplainer):
     algorithm = "IntegratedGradients"
+    algorithm_registry = _BASE_REGISTRY
 
     def __init__(self) -> None:
         super().__init__()
@@ -120,6 +131,7 @@ def compute_attributions(
 
 class _GradTrackingExplainer(AttributionOnlyExplainer):
     algorithm = "Saliency"
+    algorithm_registry = _BASE_REGISTRY
 
     def compute_attributions(
         self,
@@ -201,8 +213,7 @@ def test_explain_rejects_unknown_method_family_before_compute() -> None:
     with pytest.raises(
         Exception,
         match=(
-            "method-family inference is not implemented for framework "
-            "<unknown> and algorithm UnregisteredAlgorithm"
+            "Unknown algorithm 'UnregisteredAlgorithm' for explainer _UnknownAlgorithmExplainer"
         ),
     ):
         explainer.explain(

src/raitap/transparency/factory.py

@@ -16,6 +16,7 @@
 from .algorithm_allowlist import ensure_algorithm_in_allowlist
 from .contracts import (
     ExplainerAdapter,
+    ExplainerCapability,
     ExplanationOutputSpace,
     MethodFamily,
     explainer_output_kind,
@@ -113,14 +114,29 @@ def check_explainer_visualiser_semantic_compat(
     *,
     task_kind: TaskKind | None = None,
 ) -> None:
-    capability = explainer_capability(explainer, task_kind=task_kind)
+    # Resolve the explainer's capability lazily: only a visualiser that
+    # actually declares supported method families / output spaces gives us
+    # something to check. With nothing to check (e.g. no visualisers), we must
+    # not force method-family resolution (reading the explainer's
+    # ``algorithm_registry``) for no reason.
+    capability: ExplainerCapability | None = None
 
     for configured in visualisers:
         visualiser = configured.visualiser
         supported_method_families = _enum_frozenset(
             getattr(type(visualiser), "supported_method_families", frozenset()),
             MethodFamily,
         )
+        supported_output_spaces = _enum_frozenset(
+            getattr(type(visualiser), "supported_output_spaces", frozenset()),
+            ExplanationOutputSpace,
+        )
+        if not supported_method_families and not supported_output_spaces:
+            continue
+
+        if capability is None:
+            capability = explainer_capability(explainer, task_kind=task_kind)
+
         if supported_method_families and not (
             capability.method_families & supported_method_families
         ):
@@ -131,10 +147,6 @@ def check_explainer_visualiser_semantic_compat(
                 f"{sorted(f.value for f in supported_method_families)}."
             )
 
-        supported_output_spaces = _enum_frozenset(
-            getattr(type(visualiser), "supported_output_spaces", frozenset()),
-            ExplanationOutputSpace,
-        )
         if not supported_output_spaces:
             continue
         if capability.candidate_output_spaces & supported_output_spaces:

src/raitap/transparency/tests/test_factory.py

@@ -17,6 +17,7 @@
     VisualiserIncompatibilityError,
 )
 from raitap.transparency.contracts import (
+    ExplainerAlgorithmSpec,
     ExplanationOutputSpace,
     ExplanationPayloadKind,
     InputSpec,
@@ -519,6 +520,9 @@ def test_explanation_rejects_method_family_mismatch_before_compute(
 ) -> None:
     class GradientExplainer:
         algorithm = "Saliency"
+        algorithm_registry: ClassVar[dict[str, ExplainerAlgorithmSpec]] = {
+            "Saliency": ExplainerAlgorithmSpec({MethodFamily.GRADIENT})
+        }
         output_payload_kind: ClassVar[ExplanationPayloadKind] = ExplanationPayloadKind.ATTRIBUTIONS
 
         def __init__(self) -> None:
@@ -591,6 +595,9 @@ def test_explanation_rejects_candidate_output_space_mismatch_before_compute(
 ) -> None:
     class GradientExplainer:
         algorithm = "Saliency"
+        algorithm_registry: ClassVar[dict[str, ExplainerAlgorithmSpec]] = {
+            "Saliency": ExplainerAlgorithmSpec({MethodFamily.GRADIENT})
+        }
         output_payload_kind: ClassVar[ExplanationPayloadKind] = ExplanationPayloadKind.ATTRIBUTIONS
 
         def __init__(self) -> None:
@@ -661,6 +668,9 @@ def test_explanation_allows_any_supported_candidate_output_space_before_compute(
 ) -> None:
     class GradientExplainer:
         algorithm = "Saliency"
+        algorithm_registry: ClassVar[dict[str, ExplainerAlgorithmSpec]] = {
+            "Saliency": ExplainerAlgorithmSpec({MethodFamily.GRADIENT})
+        }
         output_payload_kind: ClassVar[ExplanationPayloadKind] = ExplanationPayloadKind.ATTRIBUTIONS
 
         def __init__(self) -> None: