fix: nullable types with gen ai bump

Merge https://github.com/google/adk-python/pull/3280

Fixes: #3281
COPYBARA_INTEGRATE_REVIEW=https://github.com/google/adk-python/pull/3280 from MarlzRana:marlzrana/fix-nullable-types-w-gen-ai-bump ad28b82cbdbb7980406086787e098bbe6478a354
PiperOrigin-RevId: 824659954

pyproject.toml

@@ -39,7 +39,7 @@ dependencies = [
   "google-cloud-spanner>=3.56.0, <4.0.0",                    # For Spanner database
   "google-cloud-speech>=2.30.0, <3.0.0",                     # For Audio Transcription
   "google-cloud-storage>=2.18.0, <3.0.0",                    # For GCS Artifact service
-  "google-genai>=1.41.0, <2.0.0",                            # Google GenAI SDK
+  "google-genai>=1.45.0, <2.0.0",                            # Google GenAI SDK
   "graphviz>=0.20.2, <1.0.0",                                # Graphviz for graph rendering
   "mcp>=1.8.0, <2.0.0;python_version>='3.10'",               # For MCP Toolset
   "opentelemetry-api>=1.37.0, <=1.37.0",                     # OpenTelemetry - limit upper version for sdk and api to not risk breaking changes from unstable _logs package.

src/google/adk/tools/_gemini_schema_util.py

@@ -74,33 +74,6 @@ def _to_snake_case(text: str) -> str:
   return text
 
 
-def _sanitize_schema_type(schema: dict[str, Any]) -> dict[str, Any]:
-  if not schema:
-    schema["type"] = "object"
-  if isinstance(schema.get("type"), list):
-    types_no_null = [t for t in schema["type"] if t != "null"]
-    nullable = len(types_no_null) != len(schema["type"])
-    if "array" in types_no_null:
-      non_null_type = "array"
-    else:
-      non_null_type = types_no_null[0] if types_no_null else "object"
-    if nullable:
-      schema["type"] = [non_null_type, "null"]
-    else:
-      schema["type"] = non_null_type
-  elif schema.get("type") == "null":
-    schema["type"] = ["object", "null"]
-
-  schema_type = schema.get("type")
-  is_array = schema_type == "array" or (
-      isinstance(schema_type, list) and "array" in schema_type
-  )
-  if is_array and "items" not in schema:
-    schema["items"] = {"type": "string"}
-
-  return schema
-
-
 def _dereference_schema(schema: dict[str, Any]) -> dict[str, Any]:
   """Resolves $ref pointers in a JSON schema."""
 
@@ -185,11 +158,15 @@ def _sanitize_schema_formats_for_gemini(
     elif field_name in supported_fields and field_value is not None:
       snake_case_schema[field_name] = field_value
 
-  return _sanitize_schema_type(snake_case_schema)
+  # If the schema is empty, assume it has the type of object
+  if not snake_case_schema:
+    snake_case_schema["type"] = "object"
+
+  return snake_case_schema
 
 
 def _to_gemini_schema(openapi_schema: dict[str, Any]) -> Schema:
-  """Converts an OpenAPI schema dictionary to a Gemini Schema object."""
+  """Converts an OpenAPI v3.1. schema dictionary to a Gemini Schema object."""
   if openapi_schema is None:
     return None
 

tests/unittests/tools/test_gemini_schema_util.py

@@ -65,14 +65,10 @@ class TestToGeminiSchema:
             "nonnullable_string": {"type": ["string"]},
             "nullable_string": {"type": ["string", "null"]},
             "nullable_number": {"type": ["null", "integer"]},
-            "object_nullable": {"type": "null"},
+            "nullable_object": {"type": ["object", "null"]},
             "multi_types_nullable": {"type": ["string", "null", "integer"]},
+            "only_null": {"type": "null"},
             "empty_default_object": {},
-            "empty_list_type": {"type": []},
-            "multi_type_with_array_nullable": {
-                "type": ["string", "array", "null"]
-            },
-            "multi_type_with_array_nonnullable": {"type": ["integer", "array"]},
         },
     }
     gemini_schema = _to_gemini_schema(openapi_schema)
@@ -89,32 +85,21 @@ class TestToGeminiSchema:
     assert gemini_schema.properties["nullable_number"].type == Type.INTEGER
     assert gemini_schema.properties["nullable_number"].nullable
 
-    assert gemini_schema.properties["object_nullable"].type == Type.OBJECT
-    assert gemini_schema.properties["object_nullable"].nullable
+    assert gemini_schema.properties["nullable_object"].type == Type.OBJECT
+    assert gemini_schema.properties["nullable_object"].nullable
 
-    assert gemini_schema.properties["multi_types_nullable"].type == Type.STRING
+    assert gemini_schema.properties["multi_types_nullable"].any_of == [
+        Schema(type=Type.STRING),
+        Schema(type=Type.INTEGER),
+    ]
     assert gemini_schema.properties["multi_types_nullable"].nullable
 
+    assert gemini_schema.properties["only_null"].type is None
+    assert gemini_schema.properties["only_null"].nullable
+
     assert gemini_schema.properties["empty_default_object"].type == Type.OBJECT
     assert gemini_schema.properties["empty_default_object"].nullable is None
 
-    assert gemini_schema.properties["empty_list_type"].type == Type.OBJECT
-    assert not gemini_schema.properties["empty_list_type"].nullable
-
-    assert (
-        gemini_schema.properties["multi_type_with_array_nullable"].type
-        == Type.ARRAY
-    )
-    assert gemini_schema.properties["multi_type_with_array_nullable"].nullable
-
-    assert (
-        gemini_schema.properties["multi_type_with_array_nonnullable"].type
-        == Type.ARRAY
-    )
-    assert not gemini_schema.properties[
-        "multi_type_with_array_nonnullable"
-    ].nullable
-
   def test_to_gemini_schema_nested_objects(self):
     openapi_schema = {
         "type": "object",
@@ -159,20 +144,6 @@ class TestToGeminiSchema:
     gemini_schema = _to_gemini_schema(openapi_schema)
     assert gemini_schema.items.properties["name"].type == Type.STRING
 
-  def test_to_gemini_schema_array_without_items_gets_default(self):
-    openapi_schema = {"type": "array"}
-    gemini_schema = _to_gemini_schema(openapi_schema)
-    assert gemini_schema.type == Type.ARRAY
-    assert not gemini_schema.nullable
-    assert gemini_schema.items.type == Type.STRING
-
-  def test_to_gemini_schema_nullable_array_without_items_gets_default(self):
-    openapi_schema = {"type": ["array", "null"]}
-    gemini_schema = _to_gemini_schema(openapi_schema)
-    assert gemini_schema.type == Type.ARRAY
-    assert gemini_schema.nullable
-    assert gemini_schema.items.type == Type.STRING
-
   def test_to_gemini_schema_any_of(self):
     openapi_schema = {
         "anyOf": [{"type": "string"}, {"type": "integer"}],
@@ -182,6 +153,14 @@ class TestToGeminiSchema:
     assert gemini_schema.any_of[0].type == Type.STRING
     assert gemini_schema.any_of[1].type == Type.INTEGER
 
+  def test_to_gemini_schema_any_of_nullable(self):
+    openapi_schema = {
+        "anyOf": [{"type": "string"}, {"type": "null"}],
+    }
+    gemini_schema = _to_gemini_schema(openapi_schema)
+    assert gemini_schema.type == Type.STRING
+    assert gemini_schema.nullable
+
   def test_to_gemini_schema_general_list(self):
     openapi_schema = {
         "type": "array",