feat(http-client-python): add mock API tests for payload/head scenario

.chronus/changes/payload-head-python-test-2026-4-17-22-55-53.md

@@ -0,0 +1,7 @@
+---
+changeKind: internal
+packages:
+  - "@typespec/http-client-python"
+---
+
+Add mock API test for `payload/head` scenario with `Content-Type` and `x-ms-meta` response headers.

packages/http-client-python/tests/mock_api/shared/asynctests/test_payload_head_async.py

@@ -0,0 +1,26 @@
+# -------------------------------------------------------------------------
+# Copyright (c) Microsoft Corporation. All rights reserved.
+# Licensed under the MIT License. See License.txt in the project root for
+# license information.
+# --------------------------------------------------------------------------
+import pytest
+import pytest_asyncio
+from payload.head.aio import HeadClient
+
+
+@pytest_asyncio.fixture
+async def client():
+    async with HeadClient(endpoint="http://localhost:3000") as client:
+        yield client
+
+
+@pytest.mark.asyncio
+async def test_content_type_header_in_response(client: HeadClient):
+    assert await client.content_type_header_in_response() is True
+
+
+@pytest.mark.asyncio
+async def test_content_type_header_in_response_with_cls(client: HeadClient):
+    headers = await client.content_type_header_in_response(cls=lambda x, y, z: z)
+    assert headers["Content-Type"] == "text/plain; charset=utf-8"
+    assert headers["x-ms-meta"] == "hello"

packages/http-client-python/tests/mock_api/shared/test_payload_head.py

@@ -0,0 +1,23 @@
+# -------------------------------------------------------------------------
+# Copyright (c) Microsoft Corporation. All rights reserved.
+# Licensed under the MIT License. See License.txt in the project root for
+# license information.
+# --------------------------------------------------------------------------
+import pytest
+from payload.head import HeadClient
+
+
+@pytest.fixture
+def client():
+    with HeadClient(endpoint="http://localhost:3000") as client:
+        yield client
+
+
+def test_content_type_header_in_response(client: HeadClient):
+    assert client.content_type_header_in_response() is True
+
+
+def test_content_type_header_in_response_with_cls(client: HeadClient):
+    headers = client.content_type_header_in_response(cls=lambda x, y, z: z)
+    assert headers["Content-Type"] == "text/plain; charset=utf-8"
+    assert headers["x-ms-meta"] == "hello"