test_functions_parallel.py

# Copyright 2026 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 google.adk.agents.llm_agent import Agent
from google.adk.events.event import Event
from google.adk.events.event_actions import EventActions
from google.adk.flows.llm_flows.functions import deep_merge_dicts
from google.adk.flows.llm_flows.functions import merge_parallel_function_response_events
from google.adk.tools.tool_context import ToolContext
from google.genai import types
import pytest

from ... import testing_utils


@pytest.mark.asyncio
async def test_parallel_function_calls_with_state_change():
  function_calls = [
      types.Part.from_function_call(
          name='update_session_state',
          args={'key': 'test_key1', 'value': 'test_value1'},
      ),
      types.Part.from_function_call(
          name='update_session_state',
          args={'key': 'test_key2', 'value': 'test_value2'},
      ),
      types.Part.from_function_call(
          name='transfer_to_agent', args={'agent_name': 'test_sub_agent'}
      ),
  ]
  function_responses = [
      types.Part.from_function_response(
          name='update_session_state', response={'result': None}
      ),
      types.Part.from_function_response(
          name='update_session_state', response={'result': None}
      ),
      types.Part.from_function_response(
          name='transfer_to_agent', response={'result': None}
      ),
  ]

  responses: list[types.Content] = [
      function_calls,
      'response1',
  ]
  function_called = 0
  mock_model = testing_utils.MockModel.create(responses=responses)

  async def update_session_state(
      key: str, value: str, tool_context: ToolContext
  ) -> None:
    nonlocal function_called
    function_called += 1
    tool_context.state.update({key: value})
    return

  async def transfer_to_agent(
      agent_name: str, tool_context: ToolContext
  ) -> None:
    nonlocal function_called
    function_called += 1
    tool_context.actions.transfer_to_agent = agent_name
    return

  test_sub_agent = Agent(
      name='test_sub_agent',
  )

  agent = Agent(
      name='root_agent',
      model=mock_model,
      tools=[update_session_state, transfer_to_agent],
      sub_agents=[test_sub_agent],
  )
  runner = testing_utils.TestInMemoryRunner(agent)
  events = await runner.run_async_with_new_session('test')

  # Notice that the following assertion only checks the "contents" part of the events.
  # The "actions" part will be checked later.
  assert testing_utils.simplify_events(events) == [
      ('root_agent', function_calls),
      ('root_agent', function_responses),
      ('test_sub_agent', 'response1'),
  ]

  # Asserts the function calls.
  assert function_called == 3

  # Asserts the actions in response event.
  response_event = events[1]

  assert response_event.actions == EventActions(
      state_delta={
          'test_key1': 'test_value1',
          'test_key2': 'test_value2',
      },
      transfer_to_agent='test_sub_agent',
  )


def test_deep_merge_dicts_concatenates_lists():
  """Test that deep_merge_dicts concatenates list values instead of overwriting."""
  d1 = {'state_delta': {'items': ['a']}}
  d2 = {'state_delta': {'items': ['b']}}
  result = deep_merge_dicts(d1, d2)
  assert result['state_delta']['items'] == ['a', 'b']


def test_deep_merge_dicts_overwrites_non_list_non_dict():
  """Test that deep_merge_dicts still overwrites scalar values."""
  d1 = {'key': 'old'}
  d2 = {'key': 'new'}
  result = deep_merge_dicts(d1, d2)
  assert result['key'] == 'new'


def test_deep_merge_dicts_merges_nested_dicts():
  """Test that deep_merge_dicts recursively merges nested dicts."""
  d1 = {'a': {'b': 1, 'c': 2}}
  d2 = {'a': {'b': 3, 'd': 4}}
  result = deep_merge_dicts(d1, d2)
  assert result == {'a': {'b': 3, 'c': 2, 'd': 4}}


def test_deep_merge_dicts_handles_mixed_list_and_non_list():
  """Test that deep_merge_dicts overwrites when types differ (list vs non-list)."""
  d1 = {'key': 'not_a_list'}
  d2 = {'key': ['a', 'b']}
  result = deep_merge_dicts(d1, d2)
  assert result['key'] == ['a', 'b']

  d1 = {'key': ['a', 'b']}
  d2 = {'key': 'not_a_list'}
  result = deep_merge_dicts(d1, d2)
  assert result['key'] == 'not_a_list'


def test_merge_parallel_function_response_events_merges_state_delta_lists():
  """Test that parallel events with list state_delta values are concatenated, not overwritten."""
  invocation_id = 'base_invocation_123'

  event1 = Event(
      invocation_id=invocation_id,
      author='tool',
      content=types.Content(
          role='user',
          parts=[
              types.Part(
                  function_response=types.FunctionResponse(
                      name='func_1',
                      response={'result': 'ok'},
                  )
              )
          ],
      ),
      actions=EventActions(state_delta={'items': ['a']}),
  )

  event2 = Event(
      invocation_id=invocation_id,
      author='tool',
      content=types.Content(
          role='user',
          parts=[
              types.Part(
                  function_response=types.FunctionResponse(
                      name='func_2',
                      response={'result': 'ok'},
                  )
              )
          ],
      ),
      actions=EventActions(state_delta={'items': ['b']}),
  )

  merged_event = merge_parallel_function_response_events([event1, event2])

  assert merged_event.actions.state_delta == {'items': ['a', 'b']}