encoding/json: rely on utf8.AppendRune

Change-Id: I50e5609ff9c5f2b216b93cec7fb5214d196cae90
Reviewed-on: https://go-review.googlesource.com/c/go/+/412537
Reviewed-by: Dmitri Shuralyov <dmitshur@google.com>
Run-TryBot: Joseph Tsai <joetsai@digital-static.net>
Reviewed-by: Ian Lance Taylor <iant@google.com>
Auto-Submit: Joseph Tsai <joetsai@digital-static.net>
TryBot-Result: Gopher Robot <gobot@golang.org>
Reviewed-by: Daniel Martí <mvdan@mvdan.cc>
Reviewed-by: Dmitri Shuralyov <dmitshur@golang.org>

diff --git a/src/encoding/json/fold_test.go b/src/encoding/json/fold_test.go
index 9fb94646a859c955b138aced46871e78922c1862..4daa3590f559f7d77c631e35f6575fcf5fab7325 100644 (file)
--- a/src/encoding/json/fold_test.go
+++ b/src/encoding/json/fold_test.go
@@ -52,9 +52,7 @@ func TestFold(t *testing.T) {
 }
 
 func TestFoldAgainstUnicode(t *testing.T) {
-       const bufSize = 5
-       buf1 := make([]byte, 0, bufSize)
-       buf2 := make([]byte, 0, bufSize)
+       var buf1, buf2 []byte
        var runes []rune
        for i := 0x20; i <= 0x7f; i++ {
                runes = append(runes, rune(i))
@@ -96,12 +94,8 @@ func TestFoldAgainstUnicode(t *testing.T) {
                                continue
                        }
                        for _, r2 := range runes {
-                               buf1 := append(buf1[:0], 'x')
-                               buf2 := append(buf2[:0], 'x')
-                               buf1 = buf1[:1+utf8.EncodeRune(buf1[1:bufSize], r)]
-                               buf2 = buf2[:1+utf8.EncodeRune(buf2[1:bufSize], r2)]
-                               buf1 = append(buf1, 'x')
-                               buf2 = append(buf2, 'x')
+                               buf1 = append(utf8.AppendRune(append(buf1[:0], 'x'), r), 'x')
+                               buf2 = append(utf8.AppendRune(append(buf2[:0], 'x'), r2), 'x')
                                want := bytes.EqualFold(buf1, buf2)
                                if got := ff.fold(buf1, buf2); got != want {
                                        t.Errorf("%s(%q, %q) = %v; want %v", ff.name, buf1, buf2, got, want)