test(events): add unit tests for Event helper methods

Add a dedicated test module for the Event class, which previously had
only incidental coverage. Covers is_final_response(), get_function_calls(),
get_function_responses(), has_trailing_code_execution_result(), and
automatic id generation, including edge cases such as events with no
content, empty parts lists, and the skip_summarization /
long_running_tool_ids early-return overrides.

Merge google/adk-python#5948

Change-Id: If05c49f82c7bb73d8c39be548434672497a770c2

Author: Koushik-Salammagari

tests/unittests/events/test_event.py

@@ -0,0 +1,190 @@
+# 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 __future__ import annotations
+
+"""Unit tests for the helper methods on the Event class."""
+
+from google.adk.events.event import Event
+from google.adk.events.event_actions import EventActions
+from google.genai import types
+
+
+def _text_part(text: str = 'hello') -> types.Part:
+  return types.Part(text=text)
+
+
+def _function_call_part(name: str = 'my_func') -> types.Part:
+  return types.Part(function_call=types.FunctionCall(name=name, args={'x': 1}))
+
+
+def _function_response_part(name: str = 'my_func') -> types.Part:
+  return types.Part(
+      function_response=types.FunctionResponse(name=name, response={'y': 2})
+  )
+
+
+def _code_execution_result_part(output: str = '42') -> types.Part:
+  return types.Part(
+      code_execution_result=types.CodeExecutionResult(
+          outcome=types.Outcome.OUTCOME_OK, output=output
+      )
+  )
+
+
+def _event(parts: list[types.Part] | None = None, **kwargs) -> Event:
+  content = (
+      types.Content(role='model', parts=parts) if parts is not None else None
+  )
+  return Event(author='agent', content=content, **kwargs)
+
+
+# --- is_final_response -------------------------------------------------------
+
+
+def test_is_final_response_plain_text_event_is_final():
+  event = _event(parts=[_text_part()])
+  assert event.is_final_response() is True
+
+
+def test_is_final_response_empty_event_is_final():
+  event = _event()
+  assert event.is_final_response() is True
+
+
+def test_is_final_response_with_function_call_is_not_final():
+  event = _event(parts=[_text_part(), _function_call_part()])
+  assert event.is_final_response() is False
+
+
+def test_is_final_response_with_function_response_is_not_final():
+  event = _event(parts=[_function_response_part()])
+  assert event.is_final_response() is False
+
+
+def test_is_final_response_partial_event_is_not_final():
+  event = _event(parts=[_text_part()], partial=True)
+  assert event.is_final_response() is False
+
+
+def test_is_final_response_with_trailing_code_result_is_not_final():
+  event = _event(parts=[_text_part(), _code_execution_result_part()])
+  assert event.is_final_response() is False
+
+
+def test_is_final_response_skip_summarization_overrides_function_response():
+  event = _event(
+      parts=[_function_response_part()],
+      actions=EventActions(skip_summarization=True),
+  )
+  assert event.is_final_response() is True
+
+
+def test_is_final_response_long_running_tool_ids_overrides_function_call():
+  event = _event(
+      parts=[_function_call_part()], long_running_tool_ids={'tool-1'}
+  )
+  assert event.is_final_response() is True
+
+
+# --- get_function_calls ------------------------------------------------------
+
+
+def test_get_function_calls_returns_calls_in_order():
+  event = _event(
+      parts=[
+          _text_part(),
+          _function_call_part('first'),
+          _function_response_part(),
+          _function_call_part('second'),
+      ]
+  )
+  assert [call.name for call in event.get_function_calls()] == [
+      'first',
+      'second',
+  ]
+
+
+def test_get_function_calls_no_content_returns_empty():
+  assert _event().get_function_calls() == []
+
+
+def test_get_function_calls_empty_parts_returns_empty():
+  assert _event(parts=[]).get_function_calls() == []
+
+
+def test_get_function_calls_text_only_returns_empty():
+  assert _event(parts=[_text_part()]).get_function_calls() == []
+
+
+# --- get_function_responses --------------------------------------------------
+
+
+def test_get_function_responses_returns_responses_in_order():
+  event = _event(
+      parts=[
+          _function_response_part('first'),
+          _text_part(),
+          _function_call_part(),
+          _function_response_part('second'),
+      ]
+  )
+  assert [resp.name for resp in event.get_function_responses()] == [
+      'first',
+      'second',
+  ]
+
+
+def test_get_function_responses_no_content_returns_empty():
+  assert _event().get_function_responses() == []
+
+
+def test_get_function_responses_empty_parts_returns_empty():
+  assert _event(parts=[]).get_function_responses() == []
+
+
+# --- has_trailing_code_execution_result --------------------------------------
+
+
+def test_has_trailing_code_execution_result_true_when_last():
+  event = _event(parts=[_text_part(), _code_execution_result_part()])
+  assert event.has_trailing_code_execution_result() is True
+
+
+def test_has_trailing_code_execution_result_false_when_not_last():
+  event = _event(parts=[_code_execution_result_part(), _text_part()])
+  assert event.has_trailing_code_execution_result() is False
+
+
+def test_has_trailing_code_execution_result_false_no_content():
+  assert _event().has_trailing_code_execution_result() is False
+
+
+def test_has_trailing_code_execution_result_false_empty_parts():
+  assert _event(parts=[]).has_trailing_code_execution_result() is False
+
+
+# --- id generation (model_post_init) -----------------------------------------
+
+
+def test_event_id_auto_assigned_when_missing():
+  assert _event().id != ''
+
+
+def test_event_ids_are_unique():
+  assert _event().id != _event().id
+
+
+def test_event_id_preserved_when_provided():
+  assert _event(id='fixed-id').id == 'fixed-id'