feat(three-stage-scan): gate stage-2 maps against split-sink ranking

tests/test_map_gate.py

@@ -0,0 +1,82 @@
+"""Stage-2 map gate: planted split-sink ranks in the high band and beats hit-count order."""
+
+from openultrasast.complexity.map import Hotspot
+from openultrasast.findings import StaticFinding
+from openultrasast.gate import LANGUAGE_MANIFESTS
+from openultrasast.map_gate import (
+    SPLIT_SINK_MANIFESTS,
+    hit_count_path_order,
+    map_beats_hit_count,
+    planted_in_high_band,
+    scan_split_sink,
+    split_sink_map_gate,
+)
+
+
+def test_split_sink_map_gate_passes_heuristic_map() -> None:
+    verdict = split_sink_map_gate()
+    assert verdict.passed, verdict.reasons
+
+
+def test_hit_count_stub_fails_map_gate_on_split_sink_python() -> None:
+    bundle = scan_split_sink("split-sink-python")
+    unique_map = list(dict.fromkeys(hotspot.path for hotspot in bundle.complexity_map.hotspots))
+    stub_order = hit_count_path_order(bundle.findings, unique_map)
+    assert stub_order != unique_map
+    assert map_beats_hit_count(bundle.complexity_map.hotspots, bundle.findings)
+
+
+def test_planted_split_sink_function_is_in_high_band() -> None:
+    bundle = scan_split_sink("split-sink-python")
+    assert planted_in_high_band(bundle.manifest, bundle.complexity_map)
+    names = {hotspot.function_name for hotspot in bundle.complexity_map.hotspots if hotspot.path == "app.py"}
+    assert "search" in names
+
+
+def test_split_sink_gate_corpus_is_not_the_stage1_smoke_gate() -> None:
+    listed = {name for names in LANGUAGE_MANIFESTS.values() for name in names}
+    assert not any(name in listed for name in SPLIT_SINK_MANIFESTS)
+
+
+def test_map_beats_hit_count_rejects_inventory_sorted_stub() -> None:
+    findings = [
+        StaticFinding(
+            finding_id="python-unsafe-eval:helper.py:1",
+            path="helper.py",
+            title="eval",
+            severity="high",
+            confidence="low",
+            evidence_level="static_corroboration",
+            rationale="hit",
+            line=1,
+            function_name="ping",
+            reachability_status="unknown",
+            reachability_evidence=[],
+            reachability_conditions=[],
+            tags=["syscall_entry"],
+            ranking_priority=1.0,
+        )
+    ]
+    stub = (
+        Hotspot(
+            path="helper.py",
+            function_name="ping",
+            score=0.1,
+            band="low",
+            signals={},
+            rationale="stub",
+            test_hint=None,
+            inventory_finding_ids=(findings[0].finding_id,),
+        ),
+        Hotspot(
+            path="app.py",
+            function_name="search",
+            score=9.0,
+            band="high",
+            signals={},
+            rationale="stub",
+            test_hint=None,
+            inventory_finding_ids=(),
+        ),
+    )
+    assert not map_beats_hit_count(stub, findings)