How to change to json string without escaping.

main.go

package main

import (
	"encoding/json"
	"fmt"
)

type IDType struct {
	Value int
	Valid bool
}

type Parent struct {
	ID         interface{} `json:"id"`
	SomeString string      `json:"some_string"`
}

func (parent *Parent) MarshalJSON() ([]byte, error) {
	// var ii interface{}
	// json.Unmarshal(&parent.ID, &ii)
	// fmt.Println(ii)
	ss := json.RawMessage(fmt.Sprintf("%v", parent.ID))
	type Alias Parent
	return json.Marshal(struct {
		*Alias
		ID interface{} `json:"id"`
	}{
		Alias: (*Alias)(parent),
		ID:    &ss,
	})
}

func main() {
	id := &IDType{Value: 1, Valid: true}
	b, _ := json.Marshal(id)
	fmt.Println(string(b))
	parent := &Parent{ID: string(b), SomeString: "Hello"}
	bb, _ := json.Marshal(parent)
	fmt.Println(string(bb))
}