From 8f40e0db2eed16621607ecfc857168240c795755 Mon Sep 17 00:00:00 2001 From: Stefan Agner Date: Mon, 1 Jun 2026 23:18:55 +0200 Subject: [PATCH] fix: support aiohttp 3.14 required stream_writer argument aiohttp 3.14.0 added a required keyword-only ``stream_writer`` argument to ``ClientResponse.__init__``. aioresponses constructs the response class without it, so every mocked response raised: TypeError: ClientResponse.__init__() missing 1 required keyword-only argument: 'stream_writer' aiohttp only reads ``stream_writer.output_size``, so a ``Mock(output_size=0)`` is sufficient. A signature check on the response class keeps this a no-op on aiohttp < 3.14 and respects custom response classes. Co-Authored-By: Claude Opus 4.8 (1M context) --- aioresponses/core.py | 6 ++++++ 1 file changed, 6 insertions(+) Index: aioresponses-0.7.8/aioresponses/core.py =================================================================== --- aioresponses-0.7.8.orig/aioresponses/core.py +++ aioresponses-0.7.8/aioresponses/core.py @@ -158,6 +158,12 @@ class RequestMatch(object): real_url=url ) kwargs['writer'] = None + # aiohttp 3.14 added a required keyword-only ``stream_writer`` argument + # to ``ClientResponse.__init__``. It is only consulted for its + # ``output_size`` attribute, so a lightweight mock is sufficient. The + # signature check keeps this a no-op on aiohttp < 3.14. + if 'stream_writer' in inspect.signature(response_class).parameters: + kwargs['stream_writer'] = Mock(output_size=0) kwargs['continue100'] = None kwargs['timer'] = TimerNoop() kwargs['traces'] = []