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/agents/test_llm_agent_fields.py

@@ -0,0 +1,231 @@
+# 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.
+
+"""Unit tests for canonical_xxx fields in LlmAgent."""
+
+from typing import Any
+from typing import Optional
+
+from google.adk.agents.callback_context import CallbackContext
+from google.adk.agents.invocation_context import InvocationContext
+from google.adk.agents.llm_agent import LlmAgent
+from google.adk.agents.loop_agent import LoopAgent
+from google.adk.agents.readonly_context import ReadonlyContext
+from google.adk.models.llm_request import LlmRequest
+from google.adk.models.registry import LLMRegistry
+from google.adk.sessions.in_memory_session_service import InMemorySessionService
+from google.genai import types
+from pydantic import BaseModel
+import pytest
+
+
+def _create_readonly_context(
+    agent: LlmAgent, state: Optional[dict[str, Any]] = None
+) -> ReadonlyContext:
+  session_service = InMemorySessionService()
+  session = session_service.create_session(
+      app_name='test_app', user_id='test_user', state=state
+  )
+  invocation_context = InvocationContext(
+      invocation_id='test_id',
+      agent=agent,
+      session=session,
+      session_service=session_service,
+  )
+  return ReadonlyContext(invocation_context)
+
+
+def test_canonical_model_empty():
+  agent = LlmAgent(name='test_agent')
+
+  with pytest.raises(ValueError):
+    _ = agent.canonical_model
+
+
+def test_canonical_model_str():
+  agent = LlmAgent(name='test_agent', model='gemini-pro')
+
+  assert agent.canonical_model.model == 'gemini-pro'
+
+
+def test_canonical_model_llm():
+  llm = LLMRegistry.new_llm('gemini-pro')
+  agent = LlmAgent(name='test_agent', model=llm)
+
+  assert agent.canonical_model == llm
+
+
+def test_canonical_model_inherit():
+  sub_agent = LlmAgent(name='sub_agent')
+  parent_agent = LlmAgent(
+      name='parent_agent', model='gemini-pro', sub_agents=[sub_agent]
+  )
+
+  assert sub_agent.canonical_model == parent_agent.canonical_model
+
+
+def test_canonical_instruction_str():
+  agent = LlmAgent(name='test_agent', instruction='instruction')
+  ctx = _create_readonly_context(agent)
+
+  assert agent.canonical_instruction(ctx) == 'instruction'
+
+
+def test_canonical_instruction():
+  def _instruction_provider(ctx: ReadonlyContext) -> str:
+    return f'instruction: {ctx.state["state_var"]}'
+
+  agent = LlmAgent(name='test_agent', instruction=_instruction_provider)
+  ctx = _create_readonly_context(agent, state={'state_var': 'state_value'})
+
+  assert agent.canonical_instruction(ctx) == 'instruction: state_value'
+
+
+def test_canonical_global_instruction_str():
+  agent = LlmAgent(name='test_agent', global_instruction='global instruction')
+  ctx = _create_readonly_context(agent)
+
+  assert agent.canonical_global_instruction(ctx) == 'global instruction'
+
+
+def test_canonical_global_instruction():
+  def _global_instruction_provider(ctx: ReadonlyContext) -> str:
+    return f'global instruction: {ctx.state["state_var"]}'
+
+  agent = LlmAgent(
+      name='test_agent', global_instruction=_global_instruction_provider
+  )
+  ctx = _create_readonly_context(agent, state={'state_var': 'state_value'})
+
+  assert (
+      agent.canonical_global_instruction(ctx)
+      == 'global instruction: state_value'
+  )
+
+
+def test_output_schema_will_disable_transfer(caplog: pytest.LogCaptureFixture):
+  with caplog.at_level('WARNING'):
+
+    class Schema(BaseModel):
+      pass
+
+    agent = LlmAgent(
+        name='test_agent',
+        output_schema=Schema,
+    )
+
+    # Transfer is automatically disabled
+    assert agent.disallow_transfer_to_parent
+    assert agent.disallow_transfer_to_peers
+    assert (
+        'output_schema cannot co-exist with agent transfer configurations.'
+        in caplog.text
+    )
+
+
+def test_output_schema_with_sub_agents_will_throw():
+  class Schema(BaseModel):
+    pass
+
+  sub_agent = LlmAgent(
+      name='sub_agent',
+  )
+
+  with pytest.raises(ValueError):
+    _ = LlmAgent(
+        name='test_agent',
+        output_schema=Schema,
+        sub_agents=[sub_agent],
+    )
+
+
+def test_output_schema_with_tools_will_throw():
+  class Schema(BaseModel):
+    pass
+
+  def _a_tool():
+    pass
+
+  with pytest.raises(ValueError):
+    _ = LlmAgent(
+        name='test_agent',
+        output_schema=Schema,
+        tools=[_a_tool],
+    )
+
+
+def test_before_model_callback():
+  def _before_model_callback(
+      callback_context: CallbackContext,
+      llm_request: LlmRequest,
+  ) -> None:
+    return None
+
+  agent = LlmAgent(
+      name='test_agent', before_model_callback=_before_model_callback
+  )
+
+  # TODO: add more logic assertions later.
+  assert agent.before_model_callback is not None
+
+
+def test_validate_generate_content_config_thinking_config_throw():
+  with pytest.raises(ValueError):
+    _ = LlmAgent(
+        name='test_agent',
+        generate_content_config=types.GenerateContentConfig(
+            thinking_config=types.ThinkingConfig()
+        ),
+    )
+
+
+def test_validate_generate_content_config_tools_throw():
+  with pytest.raises(ValueError):
+    _ = LlmAgent(
+        name='test_agent',
+        generate_content_config=types.GenerateContentConfig(
+            tools=[types.Tool(function_declarations=[])]
+        ),
+    )
+
+
+def test_validate_generate_content_config_system_instruction_throw():
+  with pytest.raises(ValueError):
+    _ = LlmAgent(
+        name='test_agent',
+        generate_content_config=types.GenerateContentConfig(
+            system_instruction='system instruction'
+        ),
+    )
+
+
+def test_validate_generate_content_config_response_schema_throw():
+  class Schema(BaseModel):
+    pass
+
+  with pytest.raises(ValueError):
+    _ = LlmAgent(
+        name='test_agent',
+        generate_content_config=types.GenerateContentConfig(
+            response_schema=Schema
+        ),
+    )
+
+
+def test_allow_transfer_by_default():
+  sub_agent = LlmAgent(name='sub_agent')
+  agent = LlmAgent(name='test_agent', sub_agents=[sub_agent])
+
+  assert not agent.disallow_transfer_to_parent
+  assert not agent.disallow_transfer_to_peers