encoding/json: add Decoder.Buffered accessor to get overread data
Otherwise it's impossible to know how much data from the
json.Decoder's underlying Reader was actually consumed.
The old fix from golang.org/issue/1955 just added docs. This
provides an actual mechanism.
Update #1955
R=golang-dev, adg, rsc
CC=golang-dev
https://golang.org/cl/7181053
diff --git a/src/pkg/encoding/json/stream_test.go b/src/pkg/encoding/json/stream_test.go
index 4d66f55..07c9e1d 100644
--- a/src/pkg/encoding/json/stream_test.go
+++ b/src/pkg/encoding/json/stream_test.go
@@ -6,8 +6,10 @@
import (
"bytes"
+ "io/ioutil"
"net"
"reflect"
+ "strings"
"testing"
)
@@ -83,6 +85,28 @@
}
}
+func TestDecoderBuffered(t *testing.T) {
+ r := strings.NewReader(`{"Name": "Gopher"} extra `)
+ var m struct {
+ Name string
+ }
+ d := NewDecoder(r)
+ err := d.Decode(&m)
+ if err != nil {
+ t.Fatal(err)
+ }
+ if m.Name != "Gopher" {
+ t.Errorf("Name = %q; want Gopher", m.Name)
+ }
+ rest, err := ioutil.ReadAll(d.Buffered())
+ if err != nil {
+ t.Fatal(err)
+ }
+ if g, w := string(rest), " extra "; g != w {
+ t.Errorf("Remaining = %q; want %q", g, w)
+ }
+}
+
func nlines(s string, n int) string {
if n <= 0 {
return ""
