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_examples.py

@@ -0,0 +1,142 @@
+# 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.
+
+# TODO: delete and rewrite unit tests
+from google.adk.agents import Agent
+from google.adk.examples import BaseExampleProvider
+from google.adk.examples import Example
+from google.adk.flows.llm_flows import examples
+from google.adk.models.base_llm import LlmRequest
+from google.genai import types
+import pytest
+
+from ... import utils
+
+
+@pytest.mark.asyncio
+async def test_no_examples():
+  request = LlmRequest(
+      model="gemini-1.5-flash",
+      config=types.GenerateContentConfig(system_instruction=""),
+  )
+  agent = Agent(model="gemini-1.5-flash", name="agent", examples=[])
+  invocation_context = utils.create_invocation_context(
+      agent=agent, user_content=""
+  )
+
+  async for _ in examples.request_processor.run_async(
+      invocation_context,
+      request,
+  ):
+    pass
+
+  assert request.config.system_instruction == ""
+
+
+@pytest.mark.asyncio
+async def test_agent_examples():
+  example_list = [
+      Example(
+          input=types.Content(
+              role="user",
+              parts=[types.Part.from_text(text="test1")],
+          ),
+          output=[
+              types.Content(
+                  role="model",
+                  parts=[types.Part.from_text(text="response1")],
+              ),
+          ],
+      )
+  ]
+  request = LlmRequest(
+      model="gemini-1.5-flash",
+      config=types.GenerateContentConfig(system_instruction=""),
+  )
+  agent = Agent(
+      model="gemini-1.5-flash",
+      name="agent",
+      examples=example_list,
+  )
+  invocation_context = utils.create_invocation_context(
+      agent=agent, user_content="test"
+  )
+
+  async for _ in examples.request_processor.run_async(
+      invocation_context,
+      request,
+  ):
+    pass
+
+  assert (
+      request.config.system_instruction
+      == "<EXAMPLES>\nBegin few-shot\nThe following are examples of user"
+      " queries and model responses using the available tools.\n\nEXAMPLE"
+      " 1:\nBegin example\n[user]\ntest1\n\n[model]\nresponse1\nEnd"
+      " example\n\nEnd few-shot\nNow, try to follow these examples and"
+      " complete the following conversation\n<EXAMPLES>"
+  )
+
+
+@pytest.mark.asyncio
+async def test_agent_base_example_provider():
+  class TestExampleProvider(BaseExampleProvider):
+
+    def get_examples(self, query: str) -> list[Example]:
+      if query == "test":
+        return [
+            Example(
+                input=types.Content(
+                    role="user",
+                    parts=[types.Part.from_text(text="test")],
+                ),
+                output=[
+                    types.Content(
+                        role="model",
+                        parts=[types.Part.from_text(text="response1")],
+                    ),
+                ],
+            )
+        ]
+      else:
+        return []
+
+  provider = TestExampleProvider()
+  request = LlmRequest(
+      model="gemini-1.5-flash",
+      config=types.GenerateContentConfig(system_instruction=""),
+  )
+  agent = Agent(
+      model="gemini-1.5-flash",
+      name="agent",
+      examples=provider,
+  )
+  invocation_context = utils.create_invocation_context(
+      agent=agent, user_content="test"
+  )
+
+  async for _ in examples.request_processor.run_async(
+      invocation_context,
+      request,
+  ):
+    pass
+
+  assert (
+      request.config.system_instruction
+      == "<EXAMPLES>\nBegin few-shot\nThe following are examples of user"
+      " queries and model responses using the available tools.\n\nEXAMPLE"
+      " 1:\nBegin example\n[user]\ntest\n\n[model]\nresponse1\nEnd"
+      " example\n\nEnd few-shot\nNow, try to follow these examples and"
+      " complete the following conversation\n<EXAMPLES>"
+  )