text/event-stream not supported #1375
Description
What version of ogen are you using?
$ go list -m github.com/ogen-go/ogen
github.com/ogen-go/ogen v1.8.1Can this issue be reproduced with the latest version?
Yes
What did you do?
Consider the following schema. Save it as openapi.yaml.
openapi: 3.0.0
info:
title: Example API
version: "1.0"
paths:
/events:
get:
summary: SSE example
responses:
"200":
description: OK
content:
text/event-stream:
schema:
type: stringRun the following terminal commands
$ go mod init repro
$ go get github.com/ogen-go/ogen/cmd/ogen
$ go run github.com/ogen-go/ogen/cmd/ogen --target gen/api -package api --clean openapi.yaml
$ go mod tidy
Create a main.go file with the following contents.
Click to view server implementation
package main
import (
"context"
"io"
"log"
"net/http"
"time"
"repro/api"
)
func main() {
srv, err := api.NewServer(&service{})
if err != nil {
log.Fatal(err)
}
if err := http.ListenAndServe(":8080", srv); err != nil {
log.Fatal(err)
}
}
type service struct{}
func (s *service) EventsGet(ctx context.Context) (api.EventsGetOK, error) {
r, w := io.Pipe()
go func() {
defer w.Close()
for ctx.Err() == nil {
select {
case <-ctx.Done():
return
case <-time.After(1 * time.Second):
w.Write([]byte("data: ping\n\n"))
}
}
}()
return api.EventsGetOK{Data: r}, nil
}Finally, start the server.
$ go run main.go
What did you expect to see?
Client can stream the response. e.g.
$ curl -N http://localhost:8080/events
data: ping
data: ping
...
What did you see instead?
The generated code in oas_response_encoders_gen.go looks like the following.
Click to view generated code
func encodeEventsGetResponse(response EventsGetOK, w http.ResponseWriter, span trace.Span) error {
w.Header().Set("Content-Type", "text/event-stream")
w.WriteHeader(200)
span.SetStatus(codes.Ok, http.StatusText(200))
writer := w
if _, err := io.Copy(writer, response); err != nil {
return errors.Wrap(err, "write")
}
return nil
}The call to io.Copy prevents streaming of response. This results in clients not receiving data.