feat: etag support

tests/ahriman/web/middlewares/test_etag_handler.py

@@ -0,0 +1,85 @@
+import hashlib
+import pytest
+
+from aiohttp import ETag
+from aiohttp.web import HTTPNotModified, Response, StreamResponse
+from unittest.mock import AsyncMock
+
+from ahriman.web.middlewares.etag_handler import etag_handler
+
+
+async def test_etag_handler() -> None:
+    """
+    must set ETag header on GET responses
+    """
+    request = pytest.helpers.request("", "", "GET")
+    request.if_none_match = None
+    request_handler = AsyncMock(return_value=Response(body=b"hello"))
+
+    handler = etag_handler()
+    result = await handler(request, request_handler)
+    assert result.etag is not None
+
+
+async def test_etag_handler_not_modified() -> None:
+    """
+    must raise NotModified when ETag matches If-None-Match
+    """
+    body = b"hello"
+    request = pytest.helpers.request("", "", "GET")
+    request.if_none_match = (ETag(value=hashlib.md5(body, usedforsecurity=False).hexdigest()),)
+    request_handler = AsyncMock(return_value=Response(body=body))
+
+    handler = etag_handler()
+    with pytest.raises(HTTPNotModified):
+        await handler(request, request_handler)
+
+
+async def test_etag_handler_no_match() -> None:
+    """
+    must return full response when ETag does not match If-None-Match
+    """
+    request = pytest.helpers.request("", "", "GET")
+    request.if_none_match = (ETag(value="outdated"),)
+    request_handler = AsyncMock(return_value=Response(body=b"hello"))
+
+    handler = etag_handler()
+    result = await handler(request, request_handler)
+    assert result.status == 200
+    assert result.etag is not None
+
+
+async def test_etag_handler_skip_post() -> None:
+    """
+    must skip ETag for non-GET/HEAD methods
+    """
+    request = pytest.helpers.request("", "", "POST")
+    request_handler = AsyncMock(return_value=Response(body=b"hello"))
+
+    handler = etag_handler()
+    result = await handler(request, request_handler)
+    assert result.etag is None
+
+
+async def test_etag_handler_skip_no_body() -> None:
+    """
+    must skip ETag for responses without body
+    """
+    request = pytest.helpers.request("", "", "GET")
+    request_handler = AsyncMock(return_value=Response())
+
+    handler = etag_handler()
+    result = await handler(request, request_handler)
+    assert result.etag is None
+
+
+async def test_etag_handler_skip_stream() -> None:
+    """
+    must skip ETag for streaming responses
+    """
+    request = pytest.helpers.request("", "", "GET")
+    request_handler = AsyncMock(return_value=StreamResponse())
+
+    handler = etag_handler()
+    result = await handler(request, request_handler)
+    assert "ETag" not in result.headers