Test code to test go-yaml make use of shared addresses when pointers are used to allow recursive parsing

test.go

package main

import (
	"errors"
	"log"

	"github.com/go-yaml/yaml"
)

type NoopRes struct {
	Path    string  `yaml:"path"`
	Content *string `yaml:"content"` // XXX *string
}

type Recursive struct {
	Self *Recursive `yaml:"self"`
	This *Recursive `yaml:"this"`
	Name string     `yaml:"name"`
}

type GraphConfig struct {
	Graph     string `yaml:"graph"`
	Resources struct {
		Noop      []*NoopRes `yaml:"noop"`
		Recursive Recursive  `yaml:"other"`
	} `yaml:"resources"`
	Comment string `yaml:"comment"`
}

func (c *GraphConfig) Parse(data []byte) error {
	if err := yaml.Unmarshal(data, c); err != nil {
		return err
	}
	if c.Graph == "" {
		return errors.New("Graph config: invalid `graph`")
	}
	return nil
}

func main() {
	log.Printf("Hello!")
	str :=
		`
---
graph: mygraph
comment: my comment
resources:
  noop:
  - name: noop1
    path: foo
    content: &ptr "hello"
  - name: noop2
    path: bar
    content: *ptr
  - name: noop3
    path: baz
    content: *ptr
  unused:
  - foo: bar
  other: &recursive
    self: *recursive
    this: *recursive
    name: Recursive item
`

	data := []byte(str)
	var config GraphConfig
	if err := config.Parse(data); err != nil {
		log.Printf("Config: Error: ParseConfigFromFile: Parse: %v", err)
		return
	}

	log.Printf("Success!")
	log.Printf("%+v", &config)
	log.Printf("%+v", config.Resources.Noop[0].Content)
	if x := config.Resources.Noop[0].Content; x != nil {
		log.Printf("inside: %+v", *config.Resources.Noop[0].Content)
	}

	log.Printf("================")

	log.Printf("%+v", config.Resources.Noop[1].Content)
	if x := config.Resources.Noop[1].Content; x != nil {
		log.Printf("inside: %+v", *x)
	} else {
		log.Printf("nothing inside!")
	}

	if config.Resources.Noop[0].Content != config.Resources.Noop[1].Content {
		log.Printf("different pointers! :( %v %v", config.Resources.Noop[0].Content, config.Resources.Noop[1].Content)
	} else {
		log.Printf("same pointers! :)")
	}

	log.Printf("================")

	log.Printf("%+v", config.Resources.Noop[2].Content)
	if x := config.Resources.Noop[2].Content; x != nil {
		log.Printf("inside: %+v", *x)
	} else {
		log.Printf("nothing inside!")
	}

	if config.Resources.Noop[1].Content != config.Resources.Noop[2].Content {
		log.Printf("different pointers! :( %v %v", config.Resources.Noop[1].Content, config.Resources.Noop[2].Content)
	} else {
		log.Printf("same pointers! :)")
	}
	log.Printf("Recursive.This.Self.This.Name: %s", config.Resources.Recursive.This.Self.This.Name)
	config.Resources.Recursive.This.Self.This.Name = "Modified Name"
	log.Printf("Recursive.This.Self.This.Name: %s", config.Resources.Recursive.This.Self.This.Self.This.Name)
}