feat(rpc): support the If-None-Match request header

If the If-None-Match header is supplied with a previously
obtained ETag from the same query, a 304 Not Modified is
returned with no content.

This allows clients to completely leverage the ETag header.
Signed-off-by: Kevin Morris <kevr@0cost.org>

aurweb/routers/rpc.py

@@ -113,6 +113,11 @@ async def rpc(request: Request,
         "ETag": f'"{etag}"'
     }
 
+    if_none_match = request.headers.get("If-None-Match", str())
+    if if_none_match and if_none_match.strip("\t\n\r\" ") == etag:
+        return Response(headers=headers,
+                        status_code=int(HTTPStatus.NOT_MODIFIED))
+
     if callback:
         content = f"/**/{callback}({content.decode()})"
 

test/test_rpc.py

 import re
 
 from http import HTTPStatus
+from typing import Dict
 from unittest import mock
 
 import orjson
@@ -28,9 +29,9 @@ from aurweb.redis import redis_connection
 from aurweb.testing import setup_test_db
 
 
-def make_request(path):
+def make_request(path, headers: Dict[str, str] = {}):
     with TestClient(app) as request:
-        return request.get(path)
+        return request.get(path, headers=headers)
 
 
 @pytest.fixture(autouse=True)
@@ -539,6 +540,13 @@ def test_rpc_search():
     result = data.get("results")[0]
     assert result.get("Name") == "big-chungus"
 
+    # Test the If-None-Match headers.
+    etag = response.headers.get("ETag").strip('"')
+    headers = {"If-None-Match": etag}
+    response = make_request("/rpc?v=5&type=search&arg=big", headers=headers)
+    assert response.status_code == int(HTTPStatus.NOT_MODIFIED)
+    assert response.content == b''
+
     # No args on non-m by types return an error.
     response = make_request("/rpc?v=5&type=search")
     assert response.json().get("error") == "No request type/data specified."