/
json.go
113 lines (102 loc) · 2.92 KB
/
json.go
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
// Copyright 2016 The OPA Authors. All rights reserved.
// Use of this source code is governed by an Apache2
// license that can be found in the LICENSE file.
package util
import (
"bytes"
"encoding/json"
"fmt"
"io"
"reflect"
"github.com/ghodss/yaml"
)
// UnmarshalJSON parses the JSON encoded data and stores the result in the value
// pointed to by x.
//
// This function is intended to be used in place of the standard json.Marshal
// function when json.Number is required.
func UnmarshalJSON(bs []byte, x interface{}) (err error) {
buf := bytes.NewBuffer(bs)
decoder := NewJSONDecoder(buf)
if err := decoder.Decode(x); err != nil {
return err
}
// Since decoder.Decode validates only the first json structure in bytes,
// check if decoder has more bytes to consume to validate whole input bytes.
tok, err := decoder.Token()
if tok != nil {
return fmt.Errorf("error: invalid character '%s' after top-level value", tok)
}
if err != nil && err != io.EOF {
return err
}
return nil
}
// NewJSONDecoder returns a new decoder that reads from r.
//
// This function is intended to be used in place of the standard json.NewDecoder
// when json.Number is required.
func NewJSONDecoder(r io.Reader) *json.Decoder {
decoder := json.NewDecoder(r)
decoder.UseNumber()
return decoder
}
// MustUnmarshalJSON parse the JSON encoded data and returns the result.
//
// If the data cannot be decoded, this function will panic. This function is for
// test purposes.
func MustUnmarshalJSON(bs []byte) interface{} {
var x interface{}
if err := UnmarshalJSON(bs, &x); err != nil {
panic(err)
}
return x
}
// MustMarshalJSON returns the JSON encoding of x
//
// If the data cannot be encoded, this function will panic. This function is for
// test purposes.
func MustMarshalJSON(x interface{}) []byte {
bs, err := json.Marshal(x)
if err != nil {
panic(err)
}
return bs
}
// RoundTrip encodes to JSON, and decodes the result again.
//
// Thereby, it is converting its argument to the representation expected by
// rego.Input and inmem's Write operations. Works with both references and
// values.
func RoundTrip(x *interface{}) error {
bs, err := json.Marshal(x)
if err != nil {
return err
}
return UnmarshalJSON(bs, x)
}
// Reference returns a pointer to its argument unless the argument already is
// a pointer. If the argument is **t, or ***t, etc, it will return *t.
//
// Used for preparing Go types (including pointers to structs) into values to be
// put through util.RoundTrip().
func Reference(x interface{}) *interface{} {
var y interface{}
rv := reflect.ValueOf(x)
if rv.Kind() == reflect.Ptr {
return Reference(rv.Elem().Interface())
}
if rv.Kind() != reflect.Invalid {
y = rv.Interface()
return &y
}
return &x
}
// Unmarshal decodes a YAML or JSON value into the specified type.
func Unmarshal(bs []byte, v interface{}) error {
bs, err := yaml.YAMLToJSON(bs)
if err != nil {
return err
}
return UnmarshalJSON(bs, v)
}