[Frontend] OpenAI Responses API supports Tool/Function calling - non-harmony (#26874)

Signed-off-by: chaunceyjiang <chaunceyjiang@gmail.com>

tests/v1/entrypoints/openai/serving_responses/conftest.py

@@ -0,0 +1,41 @@
+# SPDX-License-Identifier: Apache-2.0
+# SPDX-FileCopyrightText: Copyright contributors to the vLLM project
+import pytest
+import pytest_asyncio
+
+from tests.utils import RemoteOpenAIServer
+
+# Use a small reasoning model to test the responses API.
+MODEL_NAME = "Qwen/Qwen3-1.7B"
+
+
+@pytest.fixture(scope="module")
+def default_server_args():
+    return [
+        "--max-model-len",
+        "8192",
+        "--enforce-eager",  # For faster startup.
+        "--enable-auto-tool-choice",
+        "--structured-outputs-config.backend",
+        "xgrammar",
+        "--tool-call-parser",
+        "hermes",
+        "--reasoning-parser",
+        "qwen3",
+    ]
+
+
+@pytest.fixture(scope="module")
+def server_with_store(default_server_args):
+    with RemoteOpenAIServer(
+        MODEL_NAME,
+        default_server_args,
+        env_dict={"VLLM_ENABLE_RESPONSES_API_STORE": "1"},
+    ) as remote_server:
+        yield remote_server
+
+
+@pytest_asyncio.fixture
+async def client(server_with_store):
+    async with server_with_store.get_async_client() as async_client:
+        yield async_client