From 89d9984156c3d9fff6349ad87407ed469736b48c Mon Sep 17 00:00:00 2001
From: Marten Seemann <martenseemann@gmail.com>
Date: Tue, 22 Apr 2025 19:24:46 +0800
Subject: [PATCH] http3: simplify request writer by writing to an io.Writer
 (#5070)
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

It’s always preferable to use the most minimal interface.
---
 http3/request_writer.go      |  5 ++---
 http3/request_writer_test.go | 35 ++++++++++-------------------------
 2 files changed, 12 insertions(+), 28 deletions(-)

diff --git a/http3/request_writer.go b/http3/request_writer.go
index 2dbacb150..6d473aa63 100644
--- a/http3/request_writer.go
+++ b/http3/request_writer.go
@@ -17,7 +17,6 @@ import (
 	"golang.org/x/net/idna"
 
 	"github.com/quic-go/qpack"
-	"github.com/quic-go/quic-go"
 )
 
 const bodyCopyBufferSize = 8 * 1024
@@ -37,13 +36,13 @@ func newRequestWriter() *requestWriter {
 	}
 }
 
-func (w *requestWriter) WriteRequestHeader(str quic.Stream, req *http.Request, gzip bool) error {
+func (w *requestWriter) WriteRequestHeader(wr io.Writer, req *http.Request, gzip bool) error {
 	// TODO: figure out how to add support for trailers
 	buf := &bytes.Buffer{}
 	if err := w.writeHeaders(buf, req, gzip); err != nil {
 		return err
 	}
-	if _, err := str.Write(buf.Bytes()); err != nil {
+	if _, err := wr.Write(buf.Bytes()); err != nil {
 		return err
 	}
 	trace := httptrace.ContextClientTrace(req.Context())
diff --git a/http3/request_writer_test.go b/http3/request_writer_test.go
index 5e5d7bd49..85ee512bd 100644
--- a/http3/request_writer_test.go
+++ b/http3/request_writer_test.go
@@ -7,10 +7,8 @@ import (
 	"testing"
 
 	"github.com/quic-go/qpack"
-	mockquic "github.com/quic-go/quic-go/internal/mocks/quic"
 
 	"github.com/stretchr/testify/require"
-	"go.uber.org/mock/gomock"
 )
 
 func decodeRequest(t *testing.T, str io.Reader) map[string]string {
@@ -49,12 +47,9 @@ func testRequestWriterGzip(t *testing.T, gzip bool) {
 	req.AddCookie(&http.Cookie{Name: "baz", Value: "lorem ipsum"})
 
 	rw := newRequestWriter()
-	strBuf := &bytes.Buffer{}
-	mockCtrl := gomock.NewController(t)
-	str := mockquic.NewMockStream(mockCtrl)
-	str.EXPECT().Write(gomock.Any()).DoAndReturn(strBuf.Write).AnyTimes()
-	require.NoError(t, rw.WriteRequestHeader(str, req, gzip))
-	headerFields := decodeRequest(t, strBuf)
+	buf := &bytes.Buffer{}
+	require.NoError(t, rw.WriteRequestHeader(buf, req, gzip))
+	headerFields := decodeRequest(t, buf)
 	require.Equal(t, "quic-go.net", headerFields[":authority"])
 	require.Equal(t, http.MethodGet, headerFields[":method"])
 	require.Equal(t, "/index.html?foo=bar", headerFields[":path"])
@@ -73,12 +68,8 @@ func TestRequestWriterInvalidHostHeader(t *testing.T) {
 	require.NoError(t, err)
 	req.Host = "foo@bar" // @ is invalid
 	rw := newRequestWriter()
-	strBuf := &bytes.Buffer{}
-	mockCtrl := gomock.NewController(t)
-	str := mockquic.NewMockStream(mockCtrl)
-	str.EXPECT().Write(gomock.Any()).DoAndReturn(strBuf.Write).AnyTimes()
 	require.EqualError(t,
-		rw.WriteRequestHeader(str, req, false),
+		rw.WriteRequestHeader(&bytes.Buffer{}, req, false),
 		"http3: invalid Host header",
 	)
 }
@@ -87,12 +78,9 @@ func TestRequestWriterConnect(t *testing.T) {
 	req, err := http.NewRequest(http.MethodConnect, "https://quic-go.net/", nil)
 	require.NoError(t, err)
 	rw := newRequestWriter()
-	strBuf := &bytes.Buffer{}
-	mockCtrl := gomock.NewController(t)
-	str := mockquic.NewMockStream(mockCtrl)
-	str.EXPECT().Write(gomock.Any()).DoAndReturn(strBuf.Write).AnyTimes()
-	require.NoError(t, rw.WriteRequestHeader(str, req, false))
-	headerFields := decodeRequest(t, strBuf)
+	buf := &bytes.Buffer{}
+	require.NoError(t, rw.WriteRequestHeader(buf, req, false))
+	headerFields := decodeRequest(t, buf)
 	require.Equal(t, http.MethodConnect, headerFields[":method"])
 	require.Equal(t, "quic-go.net", headerFields[":authority"])
 	require.NotContains(t, headerFields, ":path")
@@ -105,12 +93,9 @@ func TestRequestWriterExtendedConnect(t *testing.T) {
 	require.NoError(t, err)
 	req.Proto = "webtransport"
 	rw := newRequestWriter()
-	strBuf := &bytes.Buffer{}
-	mockCtrl := gomock.NewController(t)
-	str := mockquic.NewMockStream(mockCtrl)
-	str.EXPECT().Write(gomock.Any()).DoAndReturn(strBuf.Write).AnyTimes()
-	require.NoError(t, rw.WriteRequestHeader(str, req, false))
-	headerFields := decodeRequest(t, strBuf)
+	buf := &bytes.Buffer{}
+	require.NoError(t, rw.WriteRequestHeader(buf, req, false))
+	headerFields := decodeRequest(t, buf)
 	require.Equal(t, "quic-go.net", headerFields[":authority"])
 	require.Equal(t, http.MethodConnect, headerFields[":method"])
 	require.Equal(t, "/", headerFields[":path"])