http3: check response writer for http.ResponseController methods (#5071)

http3/response_writer.go

@@ -57,6 +57,13 @@ var (
 	_ http.Flusher        = &responseWriter{}
 	_ Hijacker            = &responseWriter{}
 	_ HTTPStreamer        = &responseWriter{}
+	// make sure that we implement (some of the) methods used by the http.ResponseController
+	_ interface {
+		SetReadDeadline(time.Time) error
+		SetWriteDeadline(time.Time) error
+		Flush()
+		FlushError() error
+	} = &responseWriter{}
 )
 
 func newResponseWriter(str *stream, conn Connection, isHead bool, logger *slog.Logger) *responseWriter {

http3/response_writer_test.go

@@ -4,7 +4,6 @@ import (
 	"bytes"
 	"io"
 	"net/http"
-	"time"
 
 	"github.com/quic-go/qpack"
 	mockquic "github.com/quic-go/quic-go/internal/mocks/quic"
@@ -165,11 +164,6 @@ var _ = Describe("Response Writer", func() {
 		Expect(fields).To(HaveKeyWithValue("content-type", []string{"text/html; charset=utf-8"}))
 	})
 
-	It(`is compatible with "net/http".ResponseController`, func() {
-		Expect(rw.SetReadDeadline(time.Now().Add(1 * time.Second))).To(BeNil())
-		Expect(rw.SetWriteDeadline(time.Now().Add(1 * time.Second))).To(BeNil())
-	})
-
 	It(`checks Content-Length header`, func() {
 		rw.Header().Set("Content-Length", "6")
 		n, err := rw.Write([]byte("foobar"))