penpot/frontend
Andrey Antukh 8f91f7cd4e ✨ Negotiate transit/JSON payload format on SSE and WebSocket
SSE endpoints always encoded event payloads in transit, ignoring
request content negotiation. WebSocket notifications always used
transit as well, with no way to request plain JSON.

Extract the response format negotiation (Accept header and _fmt
query param) into the shared app.http.content-negotiation helper
and reuse it from the response formatting middleware, the SSE
response builder and the WebSocket notifications endpoint. The
_fmt=json parameter takes precedence over Accept, transit stays
the default, and unknown formats fall back to transit.

SSE event payloads are now encoded as transit (default) or plain
JSON depending on the request, while the text/event-stream
transport remains unchanged. The WebSocket format is negotiated
once on the upgrade request and applies bidirectionally: outbound
notification messages use the negotiated encoder and inbound
client messages the matching decoder, with a normalization step
converting JSON messages (:type to keyword, entity ids to UUID)
into the same shape produced by transit.

The generic websocket listener now accepts encode/decode functions
as options (defaulting to the historical transit codecs) and
exposes the resolved options in the handler metadata under
::options for testing and introspection. The notifications
http-handler is now public so tests can cover the wiring.

On the frontend, stream requests accept a :response-format :json
option that switches the Accept header and decodes each event
with the plain JSON decoder.

Add unit tests for negotiate-format, SSE response encoding and
the WebSocket codec wiring (JSON via Accept header or _fmt param,
transit default for unsignaled requests).

Closes #11409

AI-assisted-by: glm-5.3-flash
AI-assisted-by: muse-spark-1.3-contributor
2026-11-12 09:11:38 +00:00
..
2026-10-07 10:41:29 +02:00