mirror of
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0cf48b4d91
This change adds new methods to Decoder. * Decoder.Token steps through a JSON document, returning a value for each token. * Decoder.Decode unmarshals the entire value at the token stream's current position (in addition to its existing function in a stream of JSON values) Fixes #6050. Fixes #6499. Change-Id: Iff283e0e7b537221ae256392aca6529f06ebe211 Reviewed-on: https://go-review.googlesource.com/9073 Reviewed-by: Russ Cox <rsc@golang.org>
317 lines
7.6 KiB
Go
317 lines
7.6 KiB
Go
// Copyright 2010 The Go Authors. All rights reserved.
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// Use of this source code is governed by a BSD-style
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// license that can be found in the LICENSE file.
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package json
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import (
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"bytes"
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"io"
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"io/ioutil"
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"net"
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"reflect"
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"strings"
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"testing"
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)
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// Test values for the stream test.
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// One of each JSON kind.
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var streamTest = []interface{}{
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0.1,
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"hello",
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nil,
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true,
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false,
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[]interface{}{"a", "b", "c"},
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map[string]interface{}{"K": "Kelvin", "ß": "long s"},
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3.14, // another value to make sure something can follow map
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}
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var streamEncoded = `0.1
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"hello"
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null
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true
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false
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["a","b","c"]
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{"ß":"long s","K":"Kelvin"}
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3.14
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`
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func TestEncoder(t *testing.T) {
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for i := 0; i <= len(streamTest); i++ {
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var buf bytes.Buffer
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enc := NewEncoder(&buf)
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for j, v := range streamTest[0:i] {
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if err := enc.Encode(v); err != nil {
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t.Fatalf("encode #%d: %v", j, err)
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}
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}
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if have, want := buf.String(), nlines(streamEncoded, i); have != want {
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t.Errorf("encoding %d items: mismatch", i)
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diff(t, []byte(have), []byte(want))
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break
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}
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}
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}
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func TestDecoder(t *testing.T) {
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for i := 0; i <= len(streamTest); i++ {
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// Use stream without newlines as input,
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// just to stress the decoder even more.
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// Our test input does not include back-to-back numbers.
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// Otherwise stripping the newlines would
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// merge two adjacent JSON values.
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var buf bytes.Buffer
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for _, c := range nlines(streamEncoded, i) {
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if c != '\n' {
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buf.WriteRune(c)
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}
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}
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out := make([]interface{}, i)
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dec := NewDecoder(&buf)
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for j := range out {
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if err := dec.Decode(&out[j]); err != nil {
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t.Fatalf("decode #%d/%d: %v", j, i, err)
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}
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}
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if !reflect.DeepEqual(out, streamTest[0:i]) {
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t.Errorf("decoding %d items: mismatch", i)
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for j := range out {
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if !reflect.DeepEqual(out[j], streamTest[j]) {
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t.Errorf("#%d: have %v want %v", j, out[j], streamTest[j])
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}
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}
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break
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}
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}
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}
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func TestDecoderBuffered(t *testing.T) {
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r := strings.NewReader(`{"Name": "Gopher"} extra `)
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var m struct {
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Name string
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}
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d := NewDecoder(r)
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err := d.Decode(&m)
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if err != nil {
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t.Fatal(err)
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}
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if m.Name != "Gopher" {
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t.Errorf("Name = %q; want Gopher", m.Name)
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}
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rest, err := ioutil.ReadAll(d.Buffered())
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if err != nil {
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t.Fatal(err)
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}
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if g, w := string(rest), " extra "; g != w {
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t.Errorf("Remaining = %q; want %q", g, w)
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}
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}
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func nlines(s string, n int) string {
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if n <= 0 {
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return ""
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}
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for i, c := range s {
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if c == '\n' {
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if n--; n == 0 {
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return s[0 : i+1]
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}
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}
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}
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return s
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}
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func TestRawMessage(t *testing.T) {
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// TODO(rsc): Should not need the * in *RawMessage
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var data struct {
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X float64
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Id *RawMessage
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Y float32
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}
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const raw = `["\u0056",null]`
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const msg = `{"X":0.1,"Id":["\u0056",null],"Y":0.2}`
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err := Unmarshal([]byte(msg), &data)
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if err != nil {
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t.Fatalf("Unmarshal: %v", err)
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}
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if string([]byte(*data.Id)) != raw {
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t.Fatalf("Raw mismatch: have %#q want %#q", []byte(*data.Id), raw)
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}
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b, err := Marshal(&data)
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if err != nil {
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t.Fatalf("Marshal: %v", err)
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}
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if string(b) != msg {
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t.Fatalf("Marshal: have %#q want %#q", b, msg)
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}
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}
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func TestNullRawMessage(t *testing.T) {
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// TODO(rsc): Should not need the * in *RawMessage
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var data struct {
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X float64
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Id *RawMessage
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Y float32
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}
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data.Id = new(RawMessage)
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const msg = `{"X":0.1,"Id":null,"Y":0.2}`
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err := Unmarshal([]byte(msg), &data)
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if err != nil {
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t.Fatalf("Unmarshal: %v", err)
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}
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if data.Id != nil {
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t.Fatalf("Raw mismatch: have non-nil, want nil")
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}
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b, err := Marshal(&data)
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if err != nil {
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t.Fatalf("Marshal: %v", err)
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}
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if string(b) != msg {
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t.Fatalf("Marshal: have %#q want %#q", b, msg)
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}
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}
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var blockingTests = []string{
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`{"x": 1}`,
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`[1, 2, 3]`,
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}
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func TestBlocking(t *testing.T) {
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for _, enc := range blockingTests {
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r, w := net.Pipe()
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go w.Write([]byte(enc))
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var val interface{}
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// If Decode reads beyond what w.Write writes above,
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// it will block, and the test will deadlock.
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if err := NewDecoder(r).Decode(&val); err != nil {
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t.Errorf("decoding %s: %v", enc, err)
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}
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r.Close()
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w.Close()
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}
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}
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func BenchmarkEncoderEncode(b *testing.B) {
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b.ReportAllocs()
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type T struct {
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X, Y string
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}
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v := &T{"foo", "bar"}
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for i := 0; i < b.N; i++ {
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if err := NewEncoder(ioutil.Discard).Encode(v); err != nil {
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b.Fatal(err)
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}
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}
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}
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type tokenStreamCase struct {
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json string
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expTokens []interface{}
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}
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type decodeThis struct {
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v interface{}
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}
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var tokenStreamCases []tokenStreamCase = []tokenStreamCase{
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// streaming token cases
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{json: `10`, expTokens: []interface{}{float64(10)}},
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{json: ` [10] `, expTokens: []interface{}{
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Delim('['), float64(10), Delim(']')}},
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{json: ` [false,10,"b"] `, expTokens: []interface{}{
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Delim('['), false, float64(10), "b", Delim(']')}},
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{json: `{ "a": 1 }`, expTokens: []interface{}{
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Delim('{'), "a", float64(1), Delim('}')}},
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{json: `{"a": 1, "b":"3"}`, expTokens: []interface{}{
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Delim('{'), "a", float64(1), "b", "3", Delim('}')}},
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{json: ` [{"a": 1},{"a": 2}] `, expTokens: []interface{}{
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Delim('['),
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Delim('{'), "a", float64(1), Delim('}'),
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Delim('{'), "a", float64(2), Delim('}'),
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Delim(']')}},
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{json: `{"obj": {"a": 1}}`, expTokens: []interface{}{
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Delim('{'), "obj", Delim('{'), "a", float64(1), Delim('}'),
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Delim('}')}},
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{json: `{"obj": [{"a": 1}]}`, expTokens: []interface{}{
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Delim('{'), "obj", Delim('['),
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Delim('{'), "a", float64(1), Delim('}'),
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Delim(']'), Delim('}')}},
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// streaming tokens with intermittent Decode()
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{json: `{ "a": 1 }`, expTokens: []interface{}{
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Delim('{'), "a",
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decodeThis{float64(1)},
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Delim('}')}},
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{json: ` [ { "a" : 1 } ] `, expTokens: []interface{}{
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Delim('['),
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decodeThis{map[string]interface{}{"a": float64(1)}},
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Delim(']')}},
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{json: ` [{"a": 1},{"a": 2}] `, expTokens: []interface{}{
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Delim('['),
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decodeThis{map[string]interface{}{"a": float64(1)}},
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decodeThis{map[string]interface{}{"a": float64(2)}},
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Delim(']')}},
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{json: `{ "obj" : [ { "a" : 1 } ] }`, expTokens: []interface{}{
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Delim('{'), "obj", Delim('['),
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decodeThis{map[string]interface{}{"a": float64(1)}},
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Delim(']'), Delim('}')}},
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{json: `{"obj": {"a": 1}}`, expTokens: []interface{}{
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Delim('{'), "obj",
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decodeThis{map[string]interface{}{"a": float64(1)}},
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Delim('}')}},
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{json: `{"obj": [{"a": 1}]}`, expTokens: []interface{}{
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Delim('{'), "obj",
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decodeThis{[]interface{}{
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map[string]interface{}{"a": float64(1)},
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}},
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Delim('}')}},
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{json: ` [{"a": 1} {"a": 2}] `, expTokens: []interface{}{
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Delim('['),
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decodeThis{map[string]interface{}{"a": float64(1)}},
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decodeThis{&SyntaxError{"expected comma after array element", 0}},
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}},
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{json: `{ "a" 1 }`, expTokens: []interface{}{
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Delim('{'), "a",
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decodeThis{&SyntaxError{"expected colon after object key", 0}},
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}},
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}
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func TestDecodeInStream(t *testing.T) {
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for ci, tcase := range tokenStreamCases {
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dec := NewDecoder(strings.NewReader(tcase.json))
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for i, etk := range tcase.expTokens {
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var tk interface{}
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var err error
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if dt, ok := etk.(decodeThis); ok {
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etk = dt.v
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err = dec.Decode(&tk)
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} else {
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tk, err = dec.Token()
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}
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if experr, ok := etk.(error); ok {
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if err == nil || err.Error() != experr.Error() {
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t.Errorf("case %v: Expected error %v in %q, but was %v", ci, experr, tcase.json, err)
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}
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break
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} else if err == io.EOF {
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t.Errorf("case %v: Unexpected EOF in %q", ci, tcase.json)
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break
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} else if err != nil {
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t.Errorf("case %v: Unexpected error '%v' in %q", ci, err, tcase.json)
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break
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}
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if !reflect.DeepEqual(tk, etk) {
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t.Errorf(`case %v: %q @ %v expected %T(%v) was %T(%v)`, ci, tcase.json, i, etk, etk, tk, tk)
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break
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}
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}
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}
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}
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