net/textproto: use strings.Builder

Change-Id: I2ed993a804dd830b9ff445c467eb224b7aaa3401
Reviewed-on: https://go-review.googlesource.com/c/go/+/428273
Reviewed-by: Michael Knyszek <mknyszek@google.com>
Auto-Submit: Ian Lance Taylor <iant@google.com>
Run-TryBot: Ian Lance Taylor <iant@google.com>
Reviewed-by: Ian Lance Taylor <iant@google.com>
TryBot-Result: Gopher Robot <gobot@golang.org>

diff --git a/src/net/textproto/writer_test.go b/src/net/textproto/writer_test.go
index 2afef11b5eeaea35f4a2eb373f40648ed1d2527c..8f11b107888702bc30610c20eeab7034d800b4f3 100644 (file)
--- a/src/net/textproto/writer_test.go
+++ b/src/net/textproto/writer_test.go
@@ -6,12 +6,12 @@ package textproto
 
 import (
        "bufio"
-       "bytes"
+       "strings"
        "testing"
 )
 
 func TestPrintfLine(t *testing.T) {
-       var buf bytes.Buffer
+       var buf strings.Builder
        w := NewWriter(bufio.NewWriter(&buf))
        err := w.PrintfLine("foo %d", 123)
        if s := buf.String(); s != "foo 123\r\n" || err != nil {
@@ -20,7 +20,7 @@ func TestPrintfLine(t *testing.T) {
 }
 
 func TestDotWriter(t *testing.T) {
-       var buf bytes.Buffer
+       var buf strings.Builder
        w := NewWriter(bufio.NewWriter(&buf))
        d := w.DotWriter()
        n, err := d.Write([]byte("abc\n.def\n..ghi\n.jkl\n."))
@@ -35,7 +35,7 @@ func TestDotWriter(t *testing.T) {
 }
 
 func TestDotWriterCloseEmptyWrite(t *testing.T) {
-       var buf bytes.Buffer
+       var buf strings.Builder
        w := NewWriter(bufio.NewWriter(&buf))
        d := w.DotWriter()
        n, err := d.Write([]byte{})
@@ -50,7 +50,7 @@ func TestDotWriterCloseEmptyWrite(t *testing.T) {
 }
 
 func TestDotWriterCloseNoWrite(t *testing.T) {
-       var buf bytes.Buffer
+       var buf strings.Builder
        w := NewWriter(bufio.NewWriter(&buf))
        d := w.DotWriter()
        d.Close()