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/flows/llm_flows/test_functions_sequential.py

@@ -0,0 +1,93 @@
+# 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 Any
+
+from google.adk.agents import Agent
+from google.genai import types
+
+from ... import utils
+
+
+def function_call(args: dict[str, Any]) -> types.Part:
+  return types.Part.from_function_call(name='increase_by_one', args=args)
+
+
+def function_response(response: dict[str, Any]) -> types.Part:
+  return types.Part.from_function_response(
+      name='increase_by_one', response=response
+  )
+
+
+def test_sequential_calls():
+  responses = [
+      function_call({'x': 1}),
+      function_call({'x': 2}),
+      function_call({'x': 3}),
+      'response1',
+  ]
+  mockModel = utils.MockModel.create(responses=responses)
+  function_called = 0
+
+  def increase_by_one(x: int) -> int:
+    nonlocal function_called
+    function_called += 1
+    return x + 1
+
+  agent = Agent(name='root_agent', model=mockModel, tools=[increase_by_one])
+  runner = utils.InMemoryRunner(agent)
+  result = utils.simplify_events(runner.run('test'))
+  assert result == [
+      ('root_agent', function_call({'x': 1})),
+      ('root_agent', function_response({'result': 2})),
+      ('root_agent', function_call({'x': 2})),
+      ('root_agent', function_response({'result': 3})),
+      ('root_agent', function_call({'x': 3})),
+      ('root_agent', function_response({'result': 4})),
+      ('root_agent', 'response1'),
+  ]
+
+  # Asserts the requests.
+  assert len(mockModel.requests) == 4
+  # 1 item: user content
+  assert utils.simplify_contents(mockModel.requests[0].contents) == [
+      ('user', 'test')
+  ]
+  # 3 items: user content, functaion call / response for the 1st call
+  assert utils.simplify_contents(mockModel.requests[1].contents) == [
+      ('user', 'test'),
+      ('model', function_call({'x': 1})),
+      ('user', function_response({'result': 2})),
+  ]
+  # 5 items: user content, functaion call / response for two calls
+  assert utils.simplify_contents(mockModel.requests[2].contents) == [
+      ('user', 'test'),
+      ('model', function_call({'x': 1})),
+      ('user', function_response({'result': 2})),
+      ('model', function_call({'x': 2})),
+      ('user', function_response({'result': 3})),
+  ]
+  # 7 items: user content, functaion call / response for three calls
+  assert utils.simplify_contents(mockModel.requests[3].contents) == [
+      ('user', 'test'),
+      ('model', function_call({'x': 1})),
+      ('user', function_response({'result': 2})),
+      ('model', function_call({'x': 2})),
+      ('user', function_response({'result': 3})),
+      ('model', function_call({'x': 3})),
+      ('user', function_response({'result': 4})),
+  ]
+
+  # Asserts the function calls.
+  assert function_called == 3