feat: 完成 issue #43 ④ 敏感度路由规则引擎（本地/云端分级）

core/llm-gateway/tests/test_router.py

@@ -132,5 +132,59 @@ class RuleModelTest(unittest.TestCase):
         self.assertEqual(hits[0][0], "1234")
 
 
+class EngineDiagnosticsTest(unittest.TestCase):
+    """规则引擎诊断（issue #43）：priority / validate / stats / describe。"""
+
+    def test_priority_from_mapping(self):
+        rule = RouterRule.from_mapping(
+            {"name": "r", "pattern": "x", "target": "block", "priority": 1})
+        self.assertEqual(rule.priority, 1)
+        self.assertEqual(RouterRule.from_mapping(
+            {"name": "r2", "pattern": "x", "target": "local"}).priority, 0)
+
+    def test_priority_orders_rules(self):
+        # block 规则 priority=1 → 先于 local 规则（priority=10）命中
+        # 用“紧急停泵”避免命中内置 rt_emergency_cmd（pattern=停机）
+        rules = [
+            RouterRule.from_mapping(
+                {"name": "low", "pattern": "紧急停泵", "target": "local", "priority": 10}),
+            RouterRule.from_mapping(
+                {"name": "high", "pattern": "紧急停泵", "target": "block", "priority": 1}),
+        ]
+        router = SensitivityRouter(rules=rules)
+        self.assertEqual(router.route("紧急停泵").target, "block")
+        names = router.rule_names
+        self.assertLess(names.index("high"), names.index("low"))  # priority 升序
+
+    def test_validate_rules(self):
+        # 合法规则集（含内置保底）：无问题；重复名在合并时按 name 覆盖不产生冲突
+        router = SensitivityRouter(rules=[
+            RouterRule.from_mapping({"name": "a", "pattern": "x", "target": "local"}),
+        ])
+        self.assertEqual(router.validate_rules(), [])
+
+    def test_stats(self):
+        router = SensitivityRouter(rules=[
+            RouterRule.from_mapping({"name": "a", "pattern": "x", "target": "local"}),
+            RouterRule.from_mapping(
+                {"name": "b", "kind": "regex", "pattern": r"\d+", "target": "cloud"}),
+        ])
+        stats = router.stats()
+        self.assertEqual(stats["by_target"]["local"], 3)   # 内置 PII 2 条 + a
+        self.assertEqual(stats["by_target"]["cloud"], 1)
+        self.assertEqual(stats["by_kind"]["regex"], 3)  # 内置 PII 2 条 + b
+
+    def test_describe_hit_chain(self):
+        router = SensitivityRouter(rules=[
+            RouterRule.from_mapping({"name": "a", "pattern": "紧急停泵", "target": "local"}),
+            RouterRule.from_mapping(
+                {"name": "b", "pattern": "紧急停泵", "target": "block", "priority": 1}),
+        ])
+        desc = router.describe("紧急停泵")
+        names = [h["name"] for h in desc["hits"]]
+        self.assertEqual(names, ["a", "b"])   # priority 升序（a=0 先于 b=1）
+        self.assertEqual(router.route("紧急停泵").target, "local")  # 决策取首个命中（a）
+
+
 if __name__ == "__main__":
     unittest.main()