os: use strings.Builder

Change-Id: I610509aa35c345ff7fbb1fc94bf177ffbe934731
Reviewed-on: https://go-review.googlesource.com/c/go/+/428274
Reviewed-by: Ian Lance Taylor <iant@google.com>
Run-TryBot: Ian Lance Taylor <iant@google.com>
Auto-Submit: Ian Lance Taylor <iant@google.com>
TryBot-Result: Gopher Robot <gobot@golang.org>
Reviewed-by: Benny Siegert <bsiegert@gmail.com>

diff --git a/src/os/exec/example_test.go b/src/os/exec/example_test.go
index bb166ceaf4663c76e545536b8448cf5aa620e16a..150f5cff48fd70761b09df665a142bcad2c72dbb 100644 (file)
--- a/src/os/exec/example_test.go
+++ b/src/os/exec/example_test.go
@@ -5,7 +5,6 @@
 package exec_test
 
 import (
-       "bytes"
        "context"
        "encoding/json"
        "fmt"
@@ -28,7 +27,7 @@ func ExampleLookPath() {
 func ExampleCommand() {
        cmd := exec.Command("tr", "a-z", "A-Z")
        cmd.Stdin = strings.NewReader("some input")
-       var out bytes.Buffer
+       var out strings.Builder
        cmd.Stdout = &out
        err := cmd.Run()
        if err != nil {

diff --git a/src/os/exec/exec_test.go b/src/os/exec/exec_test.go
index 8f79b19eb60ac965da26d981fe06c7eb48d435fa..52001bf9e30ab480fd906ff75bf8d5ec984a8d27 100644 (file)
--- a/src/os/exec/exec_test.go
+++ b/src/os/exec/exec_test.go
@@ -804,7 +804,7 @@ func TestExtraFiles(t *testing.T) {
        }
 
        c = exec.CommandContext(ctx, exe)
-       var stdout, stderr bytes.Buffer
+       var stdout, stderr strings.Builder
        c.Stdout = &stdout
        c.Stderr = &stderr
        c.ExtraFiles = []*os.File{tf}
@@ -822,7 +822,7 @@ func TestExtraFiles(t *testing.T) {
        }
        err = c.Run()
        if err != nil {
-               t.Fatalf("Run: %v\n--- stdout:\n%s--- stderr:\n%s", err, stdout.Bytes(), stderr.Bytes())
+               t.Fatalf("Run: %v\n--- stdout:\n%s--- stderr:\n%s", err, stdout.String(), stderr.String())
        }
        if stdout.String() != text {
                t.Errorf("got stdout %q, stderr %q; want %q on stdout", stdout.String(), stderr.String(), text)
@@ -904,7 +904,7 @@ func TestIgnorePipeErrorOnSuccess(t *testing.T) {
        testWith := func(r io.Reader) func(*testing.T) {
                return func(t *testing.T) {
                        cmd := helperCommand(t, "echo", "foo")
-                       var out bytes.Buffer
+                       var out strings.Builder
                        cmd.Stdin = r
                        cmd.Stdout = &out
                        if err := cmd.Run(); err != nil {

diff --git a/src/os/os_test.go b/src/os/os_test.go
index ea935d32958aba47f60015b0a684a614a4ed4086..3f75f28938484e68c73784144c6e00cd1dde78a0 100644 (file)
--- a/src/os/os_test.go
+++ b/src/os/os_test.go
@@ -5,7 +5,6 @@
 package os_test
 
 import (
-       "bytes"
        "errors"
        "flag"
        "fmt"
@@ -1167,7 +1166,7 @@ func exec(t *testing.T, dir, cmd string, args []string, expect string) {
        }
        w.Close()
 
-       var b bytes.Buffer
+       var b strings.Builder
        io.Copy(&b, r)
        output := b.String()
 
@@ -1718,7 +1717,7 @@ func runBinHostname(t *testing.T) string {
        }
        w.Close()
 
-       var b bytes.Buffer
+       var b strings.Builder
        io.Copy(&b, r)
        _, err = p.Wait()
        if err != nil {