[]byte marshaled to null

[ash2k]

One of the fuzz tests in Kubernetes caught an issue:
This library:

{"metadata":{"selfLink":"Ǭ`/F苫ŽȢ噯榋C","resourceVersion":"4597642297830476577"},"items":[{"metadata":{"name":"玿j情1 蔝","generateName":"萀枦đ ","uid":".愥+ǽķ蓧u岏V","resourceVersion":"13323996552230461162","creationTimestamp":null},"data":{"輣 兀zʩL:Ģ梸ïĭ":"MŞFƤ趻Ă癆萃猷S幸4"},"binaryData":{"Ȟ櫤薯WDZĥȂ":null}}]}

encoding/json:

{"metadata":{"selfLink":"Ǭ`/F苫ŽȢ噯榋C","resourceVersion":"4597642297830476577"},"items":[{"metadata":{"name":"玿j情1 蔝","generateName":"萀枦đ ","uid":".愥+ǽķ蓧u岏V","resourceVersion":"13323996552230461162","creationTimestamp":null},"data":{"輣 兀zʩL:Ģ梸ïĭ":"MŞFƤ趻Ă癆萃猷S幸4"},"binaryData":{"Ȟ櫤薯WDZĥȂ":""}}]}

Notice how at the very end of the json the value in the map is not the same.
BinaryData field is declared like this:

BinaryData map[string][]byte `json:"binaryData,omitempty"`

https://github.com/kubernetes/kubernetes/blob/8f20a815e5ef27d4d247e42bff90e42706397ca2/staging/src/k8s.io/api/core/v1/types.go#L4742

Trying to migrate all encoding/json uses to this library in this PR kubernetes/kubernetes#63284

This is using commit 2ddf6d7

[panjunjie]

我也碰到这种情况了：
jsonStr:={"file":"iVBORw0KGgoAAAANSUhEUgAAAAEAAAABCAMAAAAoyzS7AAAABGdBTUEAAK/INwWK6QAAABl0RVh0U29mdHdhcmUAQWRvYmUgSW1hZ2VSZWFkeXHJZTwAAAAGUExURf///wAAAFXC034AAAABdFJOUwBA5thmAAAADElEQVR42mJgAAgwAAACAAFPbVnhAAAAAElFTkSuQmCC"}
json 字符串，其中 file 属性 是 []byte 对象，使用 json-iterator 转换成对象，file 是空值：
json.Unmarshal([]byte(jsonStr), &fileStruct)

目前只能切换回自带的 "encoding/json"

[thockin]

https://play.golang.org/p/nx9cyeks1ne

shows that stdlib json encodes a nil slice as "null" but decodes "" and "null" as a non-nil empty slice

https://play.golang.org/p/lOSZs9_fzAB

corroborates that []int follows the same pattern

@ash2k - in my experience, if you write the testcase for json-iterator that shows this behavioral difference, they will fix it :) The test case should be trivial. https://github.com/json-iterator/go/blob/master/type_tests/map_test.go I am not sure why it doesn't get caught already, truthfully.

[taowen]

sorry for the delay, the base64 decode issue has been fixed

[stevenjohnstone]

I'm not sure this has been fixed:

package main

import (
        "encoding/json"
        "fmt"

        jsoniter "github.com/json-iterator/go"
)

var json2 = jsoniter.ConfigCompatibleWithStandardLibrary

func main() {

        m := map[string][]byte{
                "foo": []byte{},
        }

        data2, err := json2.Marshal(m)
        if err != nil {
                panic(err)
        }
        fmt.Printf("jsoniter output       %s (%v)\n", string(data2), data2)

        data, err := json.Marshal(m)
        if err != nil {
                panic(err)
        }
        fmt.Printf("encoding/json output   %s (%v)\n", string(data), data)

}

$ go run main.go 
jsoniter output       {"foo":null} ([123 34 102 111 111 34 58 110 117 108 108 125])
encoding/json output   {"foo":""} ([123 34 102 111 111 34 58 34 34 125])

[maiamcc]

I'm also seeing []byte{} being marshaled to null rather than "".

(For completeness, my example provides a nil byte array as well, which I would expect to be marshaled to "null".)

Any chance of this getting addressed?

package main

import (
	"fmt"

	jsoniter "github.com/json-iterator/go"
)

func main() {
	data := map[string][]byte{
		"stuff":  []byte{}, // expect to be marshaled to ""
		"things": nil, // expect to be marshaled to "null"
	}
	jsoner := jsoniter.Config{}.Froze()
	j, err := jsoner.Marshal(data)
	if err != nil {
		panic(err)
	}
	fmt.Println(string(j))
}

$ go run main.go
{"things":null,"stuff":null}

[nikhita]

Fixed in #371