fix: Set response schema for function that returns None

PiperOrigin-RevId: 784053725

tests/unittests/tools/test_from_function_with_options.py

@@ -0,0 +1,172 @@
+# Copyright 2025 Google LLC
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+from typing import Dict
+
+from google.adk.tools import _automatic_function_calling_util
+from google.adk.utils.variant_utils import GoogleLLMVariant
+from google.genai import types
+
+
+def test_from_function_with_options_no_return_annotation_gemini():
+  """Test from_function_with_options with no return annotation for GEMINI_API."""
+
+  def test_function(param: str):
+    """A test function with no return annotation."""
+    return None
+
+  declaration = _automatic_function_calling_util.from_function_with_options(
+      test_function, GoogleLLMVariant.GEMINI_API
+  )
+
+  assert declaration.name == 'test_function'
+  assert declaration.parameters.type == 'OBJECT'
+  assert declaration.parameters.properties['param'].type == 'STRING'
+  # GEMINI_API should not have response schema
+  assert declaration.response is None
+
+
+def test_from_function_with_options_no_return_annotation_vertex():
+  """Test from_function_with_options with no return annotation for VERTEX_AI."""
+
+  def test_function(param: str):
+    """A test function with no return annotation."""
+    return None
+
+  declaration = _automatic_function_calling_util.from_function_with_options(
+      test_function, GoogleLLMVariant.VERTEX_AI
+  )
+
+  assert declaration.name == 'test_function'
+  assert declaration.parameters.type == 'OBJECT'
+  assert declaration.parameters.properties['param'].type == 'STRING'
+  # VERTEX_AI should have response schema for None return
+  assert declaration.response is not None
+  assert declaration.response.type == types.Type.NULL
+
+
+def test_from_function_with_options_explicit_none_return_vertex():
+  """Test from_function_with_options with explicit None return for VERTEX_AI."""
+
+  def test_function(param: str) -> None:
+    """A test function that explicitly returns None."""
+    pass
+
+  declaration = _automatic_function_calling_util.from_function_with_options(
+      test_function, GoogleLLMVariant.VERTEX_AI
+  )
+
+  assert declaration.name == 'test_function'
+  assert declaration.parameters.type == 'OBJECT'
+  assert declaration.parameters.properties['param'].type == 'STRING'
+  # VERTEX_AI should have response schema for explicit None return
+  assert declaration.response is not None
+  assert declaration.response.type == types.Type.NULL
+
+
+def test_from_function_with_options_explicit_none_return_gemini():
+  """Test from_function_with_options with explicit None return for GEMINI_API."""
+
+  def test_function(param: str) -> None:
+    """A test function that explicitly returns None."""
+    pass
+
+  declaration = _automatic_function_calling_util.from_function_with_options(
+      test_function, GoogleLLMVariant.GEMINI_API
+  )
+
+  assert declaration.name == 'test_function'
+  assert declaration.parameters.type == 'OBJECT'
+  assert declaration.parameters.properties['param'].type == 'STRING'
+  # GEMINI_API should not have response schema
+  assert declaration.response is None
+
+
+def test_from_function_with_options_string_return_vertex():
+  """Test from_function_with_options with string return for VERTEX_AI."""
+
+  def test_function(param: str) -> str:
+    """A test function that returns a string."""
+    return param
+
+  declaration = _automatic_function_calling_util.from_function_with_options(
+      test_function, GoogleLLMVariant.VERTEX_AI
+  )
+
+  assert declaration.name == 'test_function'
+  assert declaration.parameters.type == 'OBJECT'
+  assert declaration.parameters.properties['param'].type == 'STRING'
+  # VERTEX_AI should have response schema for string return
+  assert declaration.response is not None
+  assert declaration.response.type == types.Type.STRING
+
+
+def test_from_function_with_options_dict_return_vertex():
+  """Test from_function_with_options with dict return for VERTEX_AI."""
+
+  def test_function(param: str) -> Dict[str, str]:
+    """A test function that returns a dict."""
+    return {'result': param}
+
+  declaration = _automatic_function_calling_util.from_function_with_options(
+      test_function, GoogleLLMVariant.VERTEX_AI
+  )
+
+  assert declaration.name == 'test_function'
+  assert declaration.parameters.type == 'OBJECT'
+  assert declaration.parameters.properties['param'].type == 'STRING'
+  # VERTEX_AI should have response schema for dict return
+  assert declaration.response is not None
+  assert declaration.response.type == types.Type.OBJECT
+
+
+def test_from_function_with_options_int_return_vertex():
+  """Test from_function_with_options with int return for VERTEX_AI."""
+
+  def test_function(param: str) -> int:
+    """A test function that returns an int."""
+    return 42
+
+  declaration = _automatic_function_calling_util.from_function_with_options(
+      test_function, GoogleLLMVariant.VERTEX_AI
+  )
+
+  assert declaration.name == 'test_function'
+  assert declaration.parameters.type == 'OBJECT'
+  assert declaration.parameters.properties['param'].type == 'STRING'
+  # VERTEX_AI should have response schema for int return
+  assert declaration.response is not None
+  assert declaration.response.type == types.Type.INTEGER
+
+
+def test_from_function_with_options_no_params():
+  """Test from_function_with_options with no parameters."""
+
+  def test_function() -> None:
+    """A test function with no parameters that returns None."""
+    pass
+
+  declaration = _automatic_function_calling_util.from_function_with_options(
+      test_function, GoogleLLMVariant.VERTEX_AI
+  )
+
+  assert declaration.name == 'test_function'
+  # No parameters should result in no parameters field or empty parameters
+  assert (
+      declaration.parameters is None
+      or len(declaration.parameters.properties) == 0
+  )
+  # VERTEX_AI should have response schema for None return
+  assert declaration.response is not None
+  assert declaration.response.type == types.Type.NULL