feat: add missing UK PII entity types to Presidio guardrail (#30537)

* feat: add missing UK PII entity types to Presidio guardrail

Add UK_PASSPORT, UK_POSTCODE, and UK_VEHICLE_REGISTRATION to PiiEntityType enum and PII_ENTITY_CATEGORIES_MAP. These entity types are supported by Microsoft Presidio but were missing from litellm's type definitions, preventing users from configuring UK-specific PII detection.

* test: remove fragile hardcoded entity count test

Remove test_uk_category_entity_count which hardcodes len() == 5. The test_uk_entities_match_presidio_recognizers test already verifies exact set equality, making the count test redundant and fragile to future Presidio additions.

* style: apply Black formatting to match CI requirements

litellm/types/guardrails.py

@@ -215,6 +215,9 @@ class PiiEntityType(str, Enum):
     # UK
     UK_NHS = "UK_NHS"
     UK_NINO = "UK_NINO"
+    UK_PASSPORT = "UK_PASSPORT"
+    UK_POSTCODE = "UK_POSTCODE"
+    UK_VEHICLE_REGISTRATION = "UK_VEHICLE_REGISTRATION"
     # Spain
     ES_NIF = "ES_NIF"
     ES_NIE = "ES_NIE"
@@ -269,7 +272,13 @@ PII_ENTITY_CATEGORIES_MAP = {
         PiiEntityType.US_PASSPORT,
         PiiEntityType.US_SSN,
     ],
-    PiiEntityCategory.UK: [PiiEntityType.UK_NHS, PiiEntityType.UK_NINO],
+    PiiEntityCategory.UK: [
+        PiiEntityType.UK_NHS,
+        PiiEntityType.UK_NINO,
+        PiiEntityType.UK_PASSPORT,
+        PiiEntityType.UK_POSTCODE,
+        PiiEntityType.UK_VEHICLE_REGISTRATION,
+    ],
     PiiEntityCategory.SPAIN: [PiiEntityType.ES_NIF, PiiEntityType.ES_NIE],
     PiiEntityCategory.ITALY: [
         PiiEntityType.IT_FISCAL_CODE,
@@ -323,8 +332,7 @@ class PresidioPresidioConfigModelUserInterface(BaseModel):
     presidio_filter_scope: Optional[Literal["input", "output", "both"]] = Field(
         default=None,
         description=(
-            "Where to apply Presidio checks: 'input' (user -> model), "
-            "'output' (model -> user), or 'both' (default)."
+            "Where to apply Presidio checks: 'input' (user -> model), 'output' (model -> user), or 'both' (default)."
         ),
     )
     output_parse_pii: Optional[bool] = Field(

tests/test_litellm/types/test_uk_pii_entities.py

@@ -0,0 +1,54 @@
+"""
+Test UK PII entity types in guardrails module
+"""
+
+from litellm.types.guardrails import PiiEntityType, PiiEntityCategory, PII_ENTITY_CATEGORIES_MAP
+
+
+class TestUKPiiEntities:
+    """Test UK PII entity type definitions and mappings"""
+
+    def test_uk_pii_entity_types_exist(self):
+        """Test all UK PII entity types are defined"""
+        assert hasattr(PiiEntityType, "UK_NHS")
+        assert hasattr(PiiEntityType, "UK_NINO")
+        assert hasattr(PiiEntityType, "UK_PASSPORT")
+        assert hasattr(PiiEntityType, "UK_POSTCODE")
+        assert hasattr(PiiEntityType, "UK_VEHICLE_REGISTRATION")
+
+    def test_uk_pii_entity_values(self):
+        """Test UK PII entity types have correct string values"""
+        assert PiiEntityType.UK_NHS == "UK_NHS"
+        assert PiiEntityType.UK_NINO == "UK_NINO"
+        assert PiiEntityType.UK_PASSPORT == "UK_PASSPORT"
+        assert PiiEntityType.UK_POSTCODE == "UK_POSTCODE"
+        assert PiiEntityType.UK_VEHICLE_REGISTRATION == "UK_VEHICLE_REGISTRATION"
+
+    def test_uk_category_exists(self):
+        """Test UK category exists in PII_ENTITY_CATEGORIES_MAP"""
+        assert PiiEntityCategory.UK in PII_ENTITY_CATEGORIES_MAP
+
+    def test_uk_category_contains_all_entities(self):
+        """Test UK category contains all UK PII entity types"""
+        uk_entities = PII_ENTITY_CATEGORIES_MAP[PiiEntityCategory.UK]
+
+        assert PiiEntityType.UK_NHS in uk_entities
+        assert PiiEntityType.UK_NINO in uk_entities
+        assert PiiEntityType.UK_PASSPORT in uk_entities
+        assert PiiEntityType.UK_POSTCODE in uk_entities
+        assert PiiEntityType.UK_VEHICLE_REGISTRATION in uk_entities
+
+    def test_uk_entities_match_presidio_recognizers(self):
+        """Test UK entity type names match Presidio recognizer names"""
+        expected_entities = {
+            "UK_NHS",
+            "UK_NINO",
+            "UK_PASSPORT",
+            "UK_POSTCODE",
+            "UK_VEHICLE_REGISTRATION",
+        }
+
+        uk_entities = PII_ENTITY_CATEGORIES_MAP[PiiEntityCategory.UK]
+        actual_entities = set(uk_entities)
+
+        assert actual_entities == expected_entities