net.IP Marshalling in JSON and YAML

netIP.go

package main

import (
	"encoding/json"
	"fmt"
	"net"

	"github.com/GoogleCloudPlatform/kubernetes/Godeps/_workspace/src/gopkg.in/v1/yaml"
)

type T struct {
	IP   net.IP
	Want []string // 0 == json, 1 == yaml.
}

type encoder struct {
	f func(interface{}) ([]byte, error)
	d string
}

func main() {

	var encs = []encoder{
		{json.Marshal, "json"},
		{yaml.Marshal, "yaml"},
	}

	for _, t := range []T{
		{net.IP{}, []string{`""`, `""`}},
		{net.IPv4(127, 0, 0, 1), []string{`"127.0.0.1"`, `"127.0.0.1"`}},
	} {
		for i, s := range encs {
			got, err := s.f(t.IP)
			if err != nil {
				fmt.Println(s.d, err)
			} else if string(got) != t.Want[i] {
				fmt.Printf("%v encoding failed: wanted %q, got %q\n", s.d, t.Want[i], string(got))
			}
		}

	}
}

// Result:
// yaml encoding failed: wanted "\"\"", got "[]\n"
// yaml encoding failed: wanted "\"127.0.0.1\"", got "- 0\n- 0\n- 0\n- 0\n- 0\n- 0\n- 0\n- 0\n- 0\n- 0\n- 255\n- 255\n- 127\n- 0\n- 0\n- 1\n"