🐛 Fix: 修复 aiohttp 流式响应分块大小不固定问题 (#3919)

Co-authored-by: pre-commit-ci[bot] <66853113+pre-commit-ci[bot]@users.noreply.github.com>

nonebot/drivers/aiohttp.py

@@ -191,11 +191,26 @@ class Session(HTTPClientSession):
             timeout=timeout,
         ) as response:
             response_headers = response.headers.copy()
+            # aiohttp does not guarantee fixed-size chunks; re-chunk to exact size
+            buffer = bytearray()
             async for chunk in response.content.iter_chunked(chunk_size):
+                if not chunk:
+                    continue
+                buffer.extend(chunk)
+                while len(buffer) >= chunk_size:
+                    out = bytes(buffer[:chunk_size])
+                    del buffer[:chunk_size]
+                    yield Response(
+                        response.status,
+                        headers=response_headers,
+                        content=out,
+                        request=setup,
+                    )
+            if buffer:
                 yield Response(
                     response.status,
                     headers=response_headers,
-                    content=chunk,
+                    content=bytes(buffer),
                     request=setup,
                 )
 

tests/test_driver.py

@@ -22,6 +22,7 @@ from nonebot.drivers import (
     WebSocketClientMixin,
     WebSocketServerSetup,
 )
+from nonebot.drivers.aiohttp import Session as AiohttpSession
 from nonebot.drivers.aiohttp import WebSocket as AiohttpWebSocket
 from nonebot.exception import WebSocketClosed
 from nonebot.params import Depends
@@ -596,6 +597,46 @@ async def test_http_client_session(driver: Driver, server_url: URL):
     await anyio.sleep(1)
 
 
+@pytest.mark.anyio
+async def test_aiohttp_stream_request_skip_empty_chunk() -> None:
+    class _FakeContent:
+        async def iter_chunked(self, _: int):
+            for chunk in (b"ab", b"", b"cd", b"e"):
+                yield chunk
+
+    class _FakeResponse:
+        def __init__(self) -> None:
+            self.status = 200
+            self.headers = {"x-test": "1"}
+            self.content = _FakeContent()
+
+    class _FakeRequestContext:
+        async def __aenter__(self) -> _FakeResponse:
+            return _FakeResponse()
+
+        async def __aexit__(self, *args: object) -> bool:
+            return False
+
+    class _FakeClient:
+        def request(self, *args: object, **kwargs: object) -> _FakeRequestContext:
+            return _FakeRequestContext()
+
+    session = AiohttpSession()
+    session._client = _FakeClient()  # type: ignore[assignment]
+
+    chunks = []
+    async for resp in session.stream_request(
+        Request("GET", "https://example.com"), chunk_size=2
+    ):
+        assert resp.status_code == 200
+        assert resp.content
+        chunks.append(resp.content)
+
+    assert chunks == [b"ab", b"cd", b"e"]
+    assert b"".join(chunks) == b"abcde"
+    assert all(len(chunk) == 2 for chunk in chunks[:-1])
+
+
 @pytest.mark.anyio
 @pytest.mark.parametrize(
     "driver",