test(middleware): add cache control coverage

tests/middleware/test_cache_middleware.py

@@ -0,0 +1,66 @@
+import pytest
+from aiohttp import web
+from aiohttp.test_utils import make_mocked_request
+
+from py.middleware.cache_middleware import cache_control
+
+
+async def invoke_middleware(path: str, response: web.Response) -> web.Response:
+    async def handler(_request: web.Request) -> web.Response:
+        return response
+
+    request = make_mocked_request("GET", path)
+    return await cache_control(request, handler)
+
+
+@pytest.mark.asyncio
+@pytest.mark.parametrize(
+    "path",
+    [
+        "/static/app.js",
+        "/assets/styles/site.css",
+        "/data/index.json",
+    ],
+)
+async def test_static_files_force_no_cache(path: str) -> None:
+    response = await invoke_middleware(path, web.Response())
+
+    assert response.headers["Cache-Control"] == "no-cache"
+
+
+@pytest.mark.asyncio
+async def test_non_media_paths_leave_headers_untouched() -> None:
+    base_headers = {"X-Source": "handler"}
+    response = await invoke_middleware(
+        "/api/data", web.Response(headers=base_headers)
+    )
+
+    assert "Cache-Control" not in response.headers
+    assert response.headers["X-Source"] == "handler"
+
+
+@pytest.mark.asyncio
+@pytest.mark.parametrize(
+    "status, expected",
+    [
+        (200, "public, max-age=86400"),
+        (404, "public, max-age=3600"),
+        (302, "no-cache"),
+    ],
+)
+async def test_media_responses_set_expected_cache_control(status: int, expected: str) -> None:
+    response = await invoke_middleware(
+        "/images/sample.png", web.Response(status=status)
+    )
+
+    assert response.headers.get("Cache-Control") == expected
+
+
+@pytest.mark.asyncio
+async def test_existing_cache_control_header_preserved() -> None:
+    response = await invoke_middleware(
+        "/images/custom.jpg",
+        web.Response(headers={"Cache-Control": "public, max-age=999"}),
+    )
+
+    assert response.headers["Cache-Control"] == "public, max-age=999"