net/http: use strings.Builder

Change-Id: I754edcf21e003a3f4037fb2c5d8d06f2cd5f2fa3
Reviewed-on: https://go-review.googlesource.com/c/go/+/428267
Auto-Submit: Ian Lance Taylor <iant@google.com>
TryBot-Result: Gopher Robot <gobot@golang.org>
Run-TryBot: Ian Lance Taylor <iant@google.com>
Run-TryBot: xie cui <523516579@qq.com>
Reviewed-by: Ian Lance Taylor <iant@google.com>
Reviewed-by: Damien Neil <dneil@google.com>

10 files changed, 35 insertions, 36 deletions

diff --git a/src/net/http/cookie_test.go b/src/net/http/cookie_test.go
index 8fcf1faaa5..e5bd46a744 100644
--- a/src/net/http/cookie_test.go
+++ b/src/net/http/cookie_test.go
@@ -5,7 +5,6 @@
 package http
 
 import (
-	"bytes"
 	"encoding/json"
 	"fmt"
 	"log"
@@ -151,7 +150,7 @@ var writeSetCookiesTests = []struct {
 
 func TestWriteSetCookies(t *testing.T) {
 	defer log.SetOutput(os.Stderr)
-	var logbuf bytes.Buffer
+	var logbuf strings.Builder
 	log.SetOutput(&logbuf)
 
 	for i, tt := range writeSetCookiesTests {
@@ -482,7 +481,7 @@ func TestSetCookieDoubleQuotes(t *testing.T) {
 
 func TestCookieSanitizeValue(t *testing.T) {
 	defer log.SetOutput(os.Stderr)
-	var logbuf bytes.Buffer
+	var logbuf strings.Builder
 	log.SetOutput(&logbuf)
 
 	tests := []struct {
@@ -514,7 +513,7 @@ func TestCookieSanitizeValue(t *testing.T) {
 
 func TestCookieSanitizePath(t *testing.T) {
 	defer log.SetOutput(os.Stderr)
-	var logbuf bytes.Buffer
+	var logbuf strings.Builder
 	log.SetOutput(&logbuf)
 
 	tests := []struct {
diff --git a/src/net/http/fs_test.go b/src/net/http/fs_test.go
index 077c037c85..71fc064367 100644
--- a/src/net/http/fs_test.go
+++ b/src/net/http/fs_test.go
@@ -1273,7 +1273,7 @@ func TestLinuxSendfile(t *testing.T) {
 	}
 	defer os.Remove(filepath)
 
-	var buf bytes.Buffer
+	var buf strings.Builder
 	child := exec.Command("strace", "-f", "-q", os.Args[0], "-test.run=TestLinuxSendfileChild")
 	child.ExtraFiles = append(child.ExtraFiles, lnf)
 	child.Env = append([]string{"GO_WANT_HELPER_PROCESS=1"}, os.Environ()...)
diff --git a/src/net/http/header_test.go b/src/net/http/header_test.go
index 0b13d311ac..e98cc5c760 100644
--- a/src/net/http/header_test.go
+++ b/src/net/http/header_test.go
@@ -9,6 +9,7 @@ import (
 	"internal/race"
 	"reflect"
 	"runtime"
+	"strings"
 	"testing"
 	"time"
 )
@@ -105,7 +106,7 @@ var headerWriteTests = []struct {
 }
 
 func TestHeaderWrite(t *testing.T) {
-	var buf bytes.Buffer
+	var buf strings.Builder
 	for i, test := range headerWriteTests {
 		test.h.WriteSubset(&buf, test.exclude)
 		if buf.String() != test.expected {
diff --git a/src/net/http/readrequest_test.go b/src/net/http/readrequest_test.go
index 1950f4907a..a6a12a0ddd 100644
--- a/src/net/http/readrequest_test.go
+++ b/src/net/http/readrequest_test.go
@@ -416,7 +416,7 @@ func TestReadRequest(t *testing.T) {
 		req.Body = nil
 		testName := fmt.Sprintf("Test %d (%q)", i, tt.Raw)
 		diff(t, testName, req, tt.Req)
-		var bout bytes.Buffer
+		var bout strings.Builder
 		if rbody != nil {
 			_, err := io.Copy(&bout, rbody)
 			if err != nil {
diff --git a/src/net/http/request_test.go b/src/net/http/request_test.go
index 672c01c387..2f348284de 100644
--- a/src/net/http/request_test.go
+++ b/src/net/http/request_test.go
@@ -815,7 +815,7 @@ func TestStarRequest(t *testing.T) {
 	clientReq := *req
 	clientReq.Body = nil
 
-	var out bytes.Buffer
+	var out strings.Builder
 	if err := clientReq.Write(&out); err != nil {
 		t.Fatal(err)
 	}
@@ -823,7 +823,7 @@ func TestStarRequest(t *testing.T) {
 	if strings.Contains(out.String(), "chunked") {
 		t.Error("wrote chunked request; want no body")
 	}
-	back, err := ReadRequest(bufio.NewReader(bytes.NewReader(out.Bytes())))
+	back, err := ReadRequest(bufio.NewReader(strings.NewReader(out.String())))
 	if err != nil {
 		t.Fatal(err)
 	}
@@ -835,7 +835,7 @@ func TestStarRequest(t *testing.T) {
 		t.Errorf("Original request doesn't match Request read back.")
 		t.Logf("Original: %#v", req)
 		t.Logf("Original.URL: %#v", req.URL)
-		t.Logf("Wrote: %s", out.Bytes())
+		t.Logf("Wrote: %s", out.String())
 		t.Logf("Read back (doesn't match Original): %#v", back)
 	}
 }
@@ -983,7 +983,7 @@ func TestMaxBytesReaderDifferentLimits(t *testing.T) {
 			wantErr: false,
 		},
 		10: { /* Issue 54408 */
-			limit:   int64(1<<63-1),
+			limit:   int64(1<<63 - 1),
 			lenP:    len(testStr),
 			wantN:   len(testStr),
 			wantErr: false,
@@ -1172,7 +1172,7 @@ func testMultipartFile(t *testing.T, req *Request, key, expectFilename, expectCo
 	if fh.Filename != expectFilename {
 		t.Errorf("filename = %q, want %q", fh.Filename, expectFilename)
 	}
-	var b bytes.Buffer
+	var b strings.Builder
 	_, err = io.Copy(&b, f)
 	if err != nil {
 		t.Fatal("copying contents:", err)
diff --git a/src/net/http/requestwrite_test.go b/src/net/http/requestwrite_test.go
index bdc1e3c508..380ae9dec3 100644
--- a/src/net/http/requestwrite_test.go
+++ b/src/net/http/requestwrite_test.go
@@ -629,7 +629,7 @@ func TestRequestWrite(t *testing.T) {
 			tt.Req.Header = make(Header)
 		}
 
-		var braw bytes.Buffer
+		var braw strings.Builder
 		err := tt.Req.Write(&braw)
 		if g, e := fmt.Sprintf("%v", err), fmt.Sprintf("%v", tt.WantError); g != e {
 			t.Errorf("writing #%d, err = %q, want %q", i, g, e)
@@ -649,7 +649,7 @@ func TestRequestWrite(t *testing.T) {
 
 		if tt.WantProxy != "" {
 			setBody()
-			var praw bytes.Buffer
+			var praw strings.Builder
 			err = tt.Req.WriteProxy(&praw)
 			if err != nil {
 				t.Errorf("WriteProxy #%d: %s", i, err)
@@ -815,7 +815,7 @@ func TestRequestWriteClosesBody(t *testing.T) {
 	if err != nil {
 		t.Fatal(err)
 	}
-	buf := new(bytes.Buffer)
+	buf := new(strings.Builder)
 	if err := req.Write(buf); err != nil {
 		t.Error(err)
 	}
diff --git a/src/net/http/response_test.go b/src/net/http/response_test.go
index 2500e420dd..19fb48f23c 100644
--- a/src/net/http/response_test.go
+++ b/src/net/http/response_test.go
@@ -596,7 +596,7 @@ func TestReadResponse(t *testing.T) {
 		rbody := resp.Body
 		resp.Body = nil
 		diff(t, fmt.Sprintf("#%d Response", i), resp, &tt.Resp)
-		var bout bytes.Buffer
+		var bout strings.Builder
 		if rbody != nil {
 			_, err = io.Copy(&bout, rbody)
 			if err != nil {
@@ -809,7 +809,7 @@ func TestResponseStatusStutter(t *testing.T) {
 		ProtoMajor: 1,
 		ProtoMinor: 3,
 	}
-	var buf bytes.Buffer
+	var buf strings.Builder
 	r.Write(&buf)
 	if strings.Contains(buf.String(), "123 123") {
 		t.Errorf("stutter in status: %s", buf.String())
@@ -829,7 +829,7 @@ func TestResponseContentLengthShortBody(t *testing.T) {
 	if res.ContentLength != 123 {
 		t.Fatalf("Content-Length = %d; want 123", res.ContentLength)
 	}
-	var buf bytes.Buffer
+	var buf strings.Builder
 	n, err := io.Copy(&buf, res.Body)
 	if n != int64(len(shortBody)) {
 		t.Errorf("Copied %d bytes; want %d, len(%q)", n, len(shortBody), shortBody)
@@ -989,7 +989,7 @@ func TestResponseWritesOnlySingleConnectionClose(t *testing.T) {
 		t.Fatalf("ReadResponse failed %v", err)
 	}
 
-	var buf2 bytes.Buffer
+	var buf2 strings.Builder
 	if err = res.Write(&buf2); err != nil {
 		t.Fatalf("Write failed %v", err)
 	}
diff --git a/src/net/http/responsewrite_test.go b/src/net/http/responsewrite_test.go
index 1cc87b942e..226ad7225b 100644
--- a/src/net/http/responsewrite_test.go
+++ b/src/net/http/responsewrite_test.go
@@ -5,7 +5,6 @@
 package http
 
 import (
-	"bytes"
 	"io"
 	"strings"
 	"testing"
@@ -276,7 +275,7 @@ func TestResponseWrite(t *testing.T) {
 
 	for i := range respWriteTests {
 		tt := &respWriteTests[i]
-		var braw bytes.Buffer
+		var braw strings.Builder
 		err := tt.Resp.Write(&braw)
 		if err != nil {
 			t.Errorf("error writing #%d: %s", i, err)
diff --git a/src/net/http/serve_test.go b/src/net/http/serve_test.go
index 143874d70a..21f23c652f 100644
--- a/src/net/http/serve_test.go
+++ b/src/net/http/serve_test.go
@@ -148,7 +148,7 @@ func newHandlerTest(h Handler) handlerTest {
 
 func (ht *handlerTest) rawResponse(req string) string {
 	reqb := reqBytes(req)
-	var output bytes.Buffer
+	var output strings.Builder
 	conn := &rwTestConn{
 		Reader: bytes.NewReader(reqb),
 		Writer: &output,
@@ -3742,7 +3742,7 @@ func TestAcceptMaxFds(t *testing.T) {
 
 func TestWriteAfterHijack(t *testing.T) {
 	req := reqBytes("GET / HTTP/1.1\nHost: golang.org")
-	var buf bytes.Buffer
+	var buf strings.Builder
 	wrotec := make(chan bool, 1)
 	conn := &rwTestConn{
 		Reader: bytes.NewReader(req),
@@ -4544,7 +4544,7 @@ func TestNoContentLengthIfTransferEncoding(t *testing.T) {
 		t.Fatal(err)
 	}
 	bs := bufio.NewScanner(c)
-	var got bytes.Buffer
+	var got strings.Builder
 	for bs.Scan() {
 		if strings.TrimSpace(bs.Text()) == "" {
 			break
@@ -4633,7 +4633,7 @@ GET /should-be-ignored HTTP/1.1
 Host: foo
 
 `)
-	var buf bytes.Buffer
+	var buf strings.Builder
 	conn := &rwTestConn{
 		Reader: bytes.NewReader(req),
 		Writer: &buf,
@@ -6511,7 +6511,7 @@ func TestTimeoutHandlerSuperfluousLogs(t *testing.T) {
 				exitHandler <- true
 			}
 
-			logBuf := new(bytes.Buffer)
+			logBuf := new(strings.Builder)
 			srvLog := log.New(logBuf, "", 0)
 			// When expecting to timeout, we'll keep the duration short.
 			dur := 20 * time.Millisecond
@@ -6721,7 +6721,7 @@ func testQuerySemicolon(t *testing.T, query string, wantX string, allowSemicolon
 	}
 
 	ts := httptest.NewUnstartedServer(h)
-	logBuf := &bytes.Buffer{}
+	logBuf := &strings.Builder{}
 	ts.Config.ErrorLog = log.New(logBuf, "", 0)
 	ts.Start()
 	defer ts.Close()
diff --git a/src/net/http/transport_test.go b/src/net/http/transport_test.go
index cba35db257..e1f2a24f46 100644
--- a/src/net/http/transport_test.go
+++ b/src/net/http/transport_test.go
@@ -2444,7 +2444,7 @@ func TestTransportCancelRequestInDial(t *testing.T) {
 	if testing.Short() {
 		t.Skip("skipping test in -short mode")
 	}
-	var logbuf bytes.Buffer
+	var logbuf strings.Builder
 	eventLog := log.New(&logbuf, "", 0)
 
 	unblockDial := make(chan bool)
@@ -2931,7 +2931,7 @@ func TestTransportIgnore1xxResponses(t *testing.T) {
 	defer cst.close()
 	cst.tr.DisableKeepAlives = true // prevent log spam; our test server is hanging up anyway
 
-	var got bytes.Buffer
+	var got strings.Builder
 
 	req, _ := NewRequest("GET", cst.ts.URL, nil)
 	req = req.WithContext(httptrace.WithClientTrace(context.Background(), &httptrace.ClientTrace{
@@ -2949,7 +2949,7 @@ func TestTransportIgnore1xxResponses(t *testing.T) {
 	res.Write(&got)
 	want := "1xx: code=123, header=map[Foo:[bar]]\nHTTP/1.1 200 OK\r\nContent-Length: 5\r\nBar: baz\r\n\r\nHello"
 	if got.String() != want {
-		t.Errorf(" got: %q\nwant: %q\n", got.Bytes(), want)
+		t.Errorf(" got: %q\nwant: %q\n", got.String(), want)
 	}
 }
 
@@ -3015,7 +3015,7 @@ type proxyFromEnvTest struct {
 }
 
 func (t proxyFromEnvTest) String() string {
-	var buf bytes.Buffer
+	var buf strings.Builder
 	space := func() {
 		if buf.Len() > 0 {
 			buf.WriteByte(' ')
@@ -3537,7 +3537,7 @@ func TestRetryRequestsOnError(t *testing.T) {
 
 			var (
 				mu     sync.Mutex
-				logbuf bytes.Buffer
+				logbuf strings.Builder
 			)
 			logf := func(format string, args ...any) {
 				mu.Lock()
@@ -4515,7 +4515,7 @@ func testTransportEventTrace(t *testing.T, h2 bool, noHooks bool) {
 	cst.tr.ExpectContinueTimeout = 1 * time.Second
 
 	var mu sync.Mutex // guards buf
-	var buf bytes.Buffer
+	var buf strings.Builder
 	logf := func(format string, args ...any) {
 		mu.Lock()
 		defer mu.Unlock()
@@ -4674,7 +4674,7 @@ func testTransportEventTrace(t *testing.T, h2 bool, noHooks bool) {
 
 func TestTransportEventTraceTLSVerify(t *testing.T) {
 	var mu sync.Mutex
-	var buf bytes.Buffer
+	var buf strings.Builder
 	logf := func(format string, args ...any) {
 		mu.Lock()
 		defer mu.Unlock()
@@ -4760,7 +4760,7 @@ func TestTransportEventTraceRealDNS(t *testing.T) {
 	c := &Client{Transport: tr}
 
 	var mu sync.Mutex // guards buf
-	var buf bytes.Buffer
+	var buf strings.Builder
 	logf := func(format string, args ...any) {
 		mu.Lock()
 		defer mu.Unlock()
@@ -5978,7 +5978,7 @@ func TestTransportIgnores408(t *testing.T) {
 	// Not parallel. Relies on mutating the log package's global Output.
 	defer log.SetOutput(log.Writer())
 
-	var logout bytes.Buffer
+	var logout strings.Builder
 	log.SetOutput(&logout)
 
 	defer afterTest(t)