Moves unittests to root folder and adds github action to run unit tests. (#72)

* Move unit tests to root package.

* Adds deps to "test" extra, and mark two broken tests in tests/unittests/auth/test_auth_handler.py

* Adds github workflow

* minor fix in lite_llm.py for python 3.9.

* format pyproject.toml

tests/unittests/sessions/test_session_service.py

@@ -0,0 +1,227 @@
+# 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.
+
+import enum
+import pytest
+
+from google.adk.events import Event
+from google.adk.events import EventActions
+from google.adk.sessions import DatabaseSessionService
+from google.adk.sessions import InMemorySessionService
+from google.genai import types
+
+
+class SessionServiceType(enum.Enum):
+  IN_MEMORY = 'IN_MEMORY'
+  DATABASE = 'DATABASE'
+
+
+def get_session_service(
+    service_type: SessionServiceType = SessionServiceType.IN_MEMORY,
+):
+  """Creates a session service for testing."""
+  if service_type == SessionServiceType.DATABASE:
+    return DatabaseSessionService('sqlite:///:memory:')
+  return InMemorySessionService()
+
+
+@pytest.mark.parametrize(
+    'service_type', [SessionServiceType.IN_MEMORY, SessionServiceType.DATABASE]
+)
+def test_get_empty_session(service_type):
+  session_service = get_session_service(service_type)
+  assert not session_service.get_session(
+      app_name='my_app', user_id='test_user', session_id='123'
+  )
+
+
+@pytest.mark.parametrize(
+    'service_type', [SessionServiceType.IN_MEMORY, SessionServiceType.DATABASE]
+)
+def test_create_get_session(service_type):
+  session_service = get_session_service(service_type)
+  app_name = 'my_app'
+  user_id = 'test_user'
+  state = {'key': 'value'}
+
+  session = session_service.create_session(
+      app_name=app_name, user_id=user_id, state=state
+  )
+  assert session.app_name == app_name
+  assert session.user_id == user_id
+  assert session.id
+  assert session.state == state
+  assert (
+      session_service.get_session(
+          app_name=app_name, user_id=user_id, session_id=session.id
+      )
+      == session
+  )
+
+  session_id = session.id
+  session_service.delete_session(
+      app_name=app_name, user_id=user_id, session_id=session_id
+  )
+
+  assert (
+      not session_service.get_session(
+          app_name=app_name, user_id=user_id, session_id=session.id
+      )
+      == session
+  )
+
+
+@pytest.mark.parametrize(
+    'service_type', [SessionServiceType.IN_MEMORY, SessionServiceType.DATABASE]
+)
+def test_create_and_list_sessions(service_type):
+  session_service = get_session_service(service_type)
+  app_name = 'my_app'
+  user_id = 'test_user'
+
+  session_ids = ['session' + str(i) for i in range(5)]
+  for session_id in session_ids:
+    session_service.create_session(
+        app_name=app_name, user_id=user_id, session_id=session_id
+    )
+
+  sessions = session_service.list_sessions(
+      app_name=app_name, user_id=user_id
+  ).sessions
+  for i in range(len(sessions)):
+    assert sessions[i].id == session_ids[i]
+
+
+@pytest.mark.parametrize(
+    'service_type', [SessionServiceType.IN_MEMORY, SessionServiceType.DATABASE]
+)
+def test_session_state(service_type):
+  session_service = get_session_service(service_type)
+  app_name = 'my_app'
+  user_id_1 = 'user1'
+  user_id_2 = 'user2'
+  session_id_11 = 'session11'
+  session_id_12 = 'session12'
+  session_id_2 = 'session2'
+  state_11 = {'key11': 'value11'}
+  state_12 = {'key12': 'value12'}
+
+  session_11 = session_service.create_session(
+      app_name=app_name,
+      user_id=user_id_1,
+      state=state_11,
+      session_id=session_id_11,
+  )
+  session_service.create_session(
+      app_name=app_name,
+      user_id=user_id_1,
+      state=state_12,
+      session_id=session_id_12,
+  )
+  session_service.create_session(
+      app_name=app_name, user_id=user_id_2, session_id=session_id_2
+  )
+
+  assert session_11.state.get('key11') == 'value11'
+
+  event = Event(
+      invocation_id='invocation',
+      author='user',
+      content=types.Content(role='user', parts=[types.Part(text='text')]),
+      actions=EventActions(
+          state_delta={
+              'app:key': 'value',
+              'user:key1': 'value1',
+              'temp:key': 'temp',
+              'key11': 'value11_new',
+          }
+      ),
+  )
+  session_service.append_event(session=session_11, event=event)
+
+  # User and app state is stored, temp state is filtered.
+  assert session_11.state.get('app:key') == 'value'
+  assert session_11.state.get('key11') == 'value11_new'
+  assert session_11.state.get('user:key1') == 'value1'
+  assert not session_11.state.get('temp:key')
+
+  session_12 = session_service.get_session(
+      app_name=app_name, user_id=user_id_1, session_id=session_id_12
+  )
+  # After getting a new instance, the session_12 got the user and app state,
+  # even append_event is not applied to it, temp state has no effect
+  assert session_12.state.get('key12') == 'value12'
+  assert not session_12.state.get('temp:key')
+
+  # The user1's state is not visible to user2, app state is visible
+  session_2 = session_service.get_session(
+      app_name=app_name, user_id=user_id_2, session_id=session_id_2
+  )
+  assert session_2.state.get('app:key') == 'value'
+  assert not session_2.state.get('user:key1')
+
+  assert not session_2.state.get('user:key1')
+
+  # The change to session_11 is persisted
+  session_11 = session_service.get_session(
+      app_name=app_name, user_id=user_id_1, session_id=session_id_11
+  )
+  assert session_11.state.get('key11') == 'value11_new'
+  assert session_11.state.get('user:key1') == 'value1'
+  assert not session_11.state.get('temp:key')
+
+
+@pytest.mark.parametrize(
+    "service_type", [SessionServiceType.IN_MEMORY, SessionServiceType.DATABASE]
+)
+def test_create_new_session_will_merge_states(service_type):
+  session_service = get_session_service(service_type)
+  app_name = 'my_app'
+  user_id = 'user'
+  session_id_1 = 'session1'
+  session_id_2 = 'session2'
+  state_1 = {'key1': 'value1'}
+
+  session_1 = session_service.create_session(
+      app_name=app_name, user_id=user_id, state=state_1, session_id=session_id_1
+  )
+
+  event = Event(
+      invocation_id='invocation',
+      author='user',
+      content=types.Content(role='user', parts=[types.Part(text='text')]),
+      actions=EventActions(
+          state_delta={
+              'app:key': 'value',
+              'user:key1': 'value1',
+              'temp:key': 'temp',
+          }
+      ),
+  )
+  session_service.append_event(session=session_1, event=event)
+
+  # User and app state is stored, temp state is filtered.
+  assert session_1.state.get('app:key') == 'value'
+  assert session_1.state.get('key1') == 'value1'
+  assert session_1.state.get('user:key1') == 'value1'
+  assert not session_1.state.get('temp:key')
+
+  session_2 = session_service.create_session(
+      app_name=app_name, user_id=user_id, state={}, session_id=session_id_2
+  )
+  # Session 2 has the persisted states
+  assert session_2.state.get('app:key') == 'value'
+  assert session_2.state.get('user:key1') == 'value1'
+  assert not session_2.state.get('key1')
+  assert not session_2.state.get('temp:key')