yaml_test.go

package yaml_test

import (
	"bytes"
	"testing"

	"github.com/google/go-cmp/cmp"
	"golang.org/x/xerrors"

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

func TestMarshal(t *testing.T) {
	var v struct {
		A int
		B string
	}
	v.A = 1
	v.B = "hello"
	bytes, err := yaml.Marshal(v)
	if err != nil {
		t.Fatalf("%+v", err)
	}
	if string(bytes) != "a: 1\nb: hello\n" {
		t.Fatal("failed to marshal")
	}
}

func TestUnmarshal(t *testing.T) {
	yml := `
%YAML 1.2
---
a: 1
b: c
`
	var v struct {
		A int
		B string
	}
	if err := yaml.Unmarshal([]byte(yml), &v); err != nil {
		t.Fatalf("%+v", err)
	}
}

type marshalTest struct{}

func (t *marshalTest) MarshalYAML() ([]byte, error) {
	return yaml.Marshal(yaml.MapSlice{
		{
			"a", 1,
		},
		{
			"b", "hello",
		},
		{
			"c", true,
		},
		{
			"d", map[string]string{"x": "y"},
		},
	})
}

type marshalTest2 struct{}

func (t *marshalTest2) MarshalYAML() (interface{}, error) {
	return yaml.MapSlice{
		{
			"a", 2,
		},
		{
			"b", "world",
		},
		{
			"c", true,
		},
	}, nil
}

func TestMarshalYAML(t *testing.T) {
	var v struct {
		A *marshalTest
		B *marshalTest2
	}
	v.A = &marshalTest{}
	v.B = &marshalTest2{}
	bytes, err := yaml.Marshal(v)
	if err != nil {
		t.Fatalf("failed to Marshal: %+v", err)
	}
	expect := `
a:
  a: 1
  b: hello
  c: true
  d:
    x: "y"
b:
  a: 2
  b: world
  c: true
`
	actual := "\n" + string(bytes)
	if expect != actual {
		t.Fatalf("failed to MarshalYAML expect:[%s], actual:[%s]", expect, actual)
	}
}

type unmarshalTest struct {
	a int
	b string
	c bool
}

func (t *unmarshalTest) UnmarshalYAML(b []byte) error {
	if t.a != 0 {
		return xerrors.New("unexpected field value to a")
	}
	if t.b != "" {
		return xerrors.New("unexpected field value to b")
	}
	if t.c {
		return xerrors.New("unexpected field value to c")
	}
	var v struct {
		A int
		B string
		C bool
	}
	if err := yaml.Unmarshal(b, &v); err != nil {
		return err
	}
	t.a = v.A
	t.b = v.B
	t.c = v.C
	return nil
}

type unmarshalTest2 struct {
	a int
	b string
	c bool
}

func (t *unmarshalTest2) UnmarshalYAML(unmarshal func(interface{}) error) error {
	var v struct {
		A int
		B string
		C bool
	}
	if t.a != 0 {
		return xerrors.New("unexpected field value to a")
	}
	if t.b != "" {
		return xerrors.New("unexpected field value to b")
	}
	if t.c {
		return xerrors.New("unexpected field value to c")
	}
	if err := unmarshal(&v); err != nil {
		return err
	}
	t.a = v.A
	t.b = v.B
	t.c = v.C
	return nil
}

func TestUnmarshalYAML(t *testing.T) {
	yml := `
a:
  a: 1
  b: hello
  c: true
b:
  a: 2
  b: world
  c: true
`
	var v struct {
		A *unmarshalTest
		B *unmarshalTest2
	}
	if err := yaml.Unmarshal([]byte(yml), &v); err != nil {
		t.Fatalf("failed to Unmarshal: %+v", err)
	}
	if v.A == nil {
		t.Fatal("failed to UnmarshalYAML")
	}
	if v.A.a != 1 {
		t.Fatal("failed to UnmarshalYAML")
	}
	if v.A.b != "hello" {
		t.Fatal("failed to UnmarshalYAML")
	}
	if !v.A.c {
		t.Fatal("failed to UnmarshalYAML")
	}
	if v.B == nil {
		t.Fatal("failed to UnmarshalYAML")
	}
	if v.B.a != 2 {
		t.Fatal("failed to UnmarshalYAML")
	}
	if v.B.b != "world" {
		t.Fatal("failed to UnmarshalYAML")
	}
	if !v.B.c {
		t.Fatal("failed to UnmarshalYAML")
	}
}

type ObjectMap map[string]*Object
type ObjectDecl struct {
	Name    string `yaml:"-"`
	*Object `yaml:",inline,anchor"`
}

func (m ObjectMap) MarshalYAML() (interface{}, error) {
	newMap := map[string]*ObjectDecl{}
	for k, v := range m {
		newMap[k] = &ObjectDecl{Name: k, Object: v}
	}
	return newMap, nil
}

type rootObject struct {
	Single     ObjectMap            `yaml:"single"`
	Collection map[string][]*Object `yaml:"collection"`
}

type Object struct {
	*Object  `yaml:",omitempty,inline,alias"`
	MapValue map[string]interface{} `yaml:",omitempty,inline"`
}

func TestInlineAnchorAndAlias(t *testing.T) {
	yml := `---
single:
  default: &default
    id: 1
    name: john
  user_1: &user_1
    id: 1
    name: ken
  user_2: &user_2
    <<: *default
    id: 2
collection:
  defaults:
  - *default
  - <<: *default
  - <<: *default
    id: 2
  users:
  - <<: *user_1
  - <<: *user_2
  - <<: *user_1
    id: 3
  - <<: *user_1
    id: 4
  - <<: *user_1
    id: 5
`
	var v rootObject
	if err := yaml.Unmarshal([]byte(yml), &v); err != nil {
		t.Fatal(err)
	}
	opt := yaml.MarshalAnchor(func(anchor *ast.AnchorNode, value interface{}) error {
		if o, ok := value.(*ObjectDecl); ok {
			return anchor.SetName(o.Name)
		}
		return nil
	})
	var buf bytes.Buffer
	if err := yaml.NewEncoder(&buf, opt).Encode(v); err != nil {
		t.Fatalf("%+v", err)
	}
	actual := "---\n" + buf.String()
	if yml != actual {
		t.Fatalf("failed to marshal: expected:[%s] actual:[%s]", yml, actual)
	}
}

func TestMapSlice_Map(t *testing.T) {
	yml := `
a: b
c: d
`
	var v yaml.MapSlice
	if err := yaml.Unmarshal([]byte(yml), &v); err != nil {
		t.Fatal(err)
	}
	m := v.ToMap()
	if len(m) != 2 {
		t.Fatal("failed to convert MapSlice to map")
	}
	if m["a"] != "b" {
		t.Fatal("failed to convert MapSlice to map")
	}
	if m["c"] != "d" {
		t.Fatal("failed to convert MapSlice to map")
	}
}

func TestMarshalWithModifiedAnchorAlias(t *testing.T) {
	yml := `
a: &a 1
b: *a
`
	var v struct {
		A *int `yaml:"a,anchor"`
		B *int `yaml:"b,alias"`
	}
	if err := yaml.Unmarshal([]byte(yml), &v); err != nil {
		t.Fatal(err)
	}
	node, err := yaml.ValueToNode(v)
	if err != nil {
		t.Fatal(err)
	}
	anchors := ast.Filter(ast.AnchorType, node)
	if len(anchors) != 1 {
		t.Fatal("failed to filter node")
	}
	anchor := anchors[0].(*ast.AnchorNode)
	if err := anchor.SetName("b"); err != nil {
		t.Fatal(err)
	}
	aliases := ast.Filter(ast.AliasType, node)
	if len(anchors) != 1 {
		t.Fatal("failed to filter node")
	}
	alias := aliases[0].(*ast.AliasNode)
	if err := alias.SetName("b"); err != nil {
		t.Fatal(err)
	}

	expected := `
a: &b 1
b: *b`

	actual := "\n" + node.String()
	if expected != actual {
		t.Fatalf("failed to marshal: expected:[%q] but got [%q]", expected, actual)
	}
}

func Test_YAMLToJSON(t *testing.T) {
	yml := `
foo:
  bar:
  - a
  - b
  - c
a: 1
`
	actual, err := yaml.YAMLToJSON([]byte(yml))
	if err != nil {
		t.Fatal(err)
	}
	expected := `{"foo": {"bar": ["a", "b", "c"]}, "a": 1}`
	if expected+"\n" != string(actual) {
		t.Fatalf("failed to convert yaml to json: expected [%q] but got [%q]", expected, actual)
	}
}

func Test_JSONToYAML(t *testing.T) {
	json := `{"foo": {"bar": ["a", "b", "c"]}, "a": 1}`
	expected := `
foo:
  bar:
  - a
  - b
  - c
a: 1
`
	actual, err := yaml.JSONToYAML([]byte(json))
	if err != nil {
		t.Fatal(err)
	}
	if expected != "\n"+string(actual) {
		t.Fatalf("failed to convert json to yaml: expected [%q] but got [%q]", expected, actual)
	}
}

func Test_WithCommentOption(t *testing.T) {
	t.Run("line comment", func(t *testing.T) {
		v := struct {
			Foo string                 `yaml:"foo"`
			Bar map[string]interface{} `yaml:"bar"`
			Baz struct {
				X int `yaml:"x"`
			} `yaml:"baz"`
		}{
			Foo: "aaa",
			Bar: map[string]interface{}{"bbb": "ccc"},
			Baz: struct {
				X int `yaml:"x"`
			}{X: 10},
		}
		b, err := yaml.MarshalWithOptions(v, yaml.WithComment(
			yaml.CommentMap{
				"$.foo":     []*yaml.Comment{yaml.LineComment("foo comment")},
				"$.bar":     []*yaml.Comment{yaml.LineComment("bar comment")},
				"$.bar.bbb": []*yaml.Comment{yaml.LineComment("bbb comment")},
				"$.baz.x":   []*yaml.Comment{yaml.LineComment("x comment")},
			},
		))
		if err != nil {
			t.Fatal(err)
		}
		expected := `
foo: aaa #foo comment
bar: #bar comment
  bbb: ccc #bbb comment
baz:
  x: 10 #x comment
`
		actual := "\n" + string(b)
		if expected != actual {
			t.Fatalf("expected:%s but got %s", expected, actual)
		}
	})
	t.Run("line comment2", func(t *testing.T) {
		v := struct {
			Foo map[string]interface{} `yaml:"foo"`
		}{
			Foo: map[string]interface{}{
				"bar": map[string]interface{}{
					"baz": true,
				},
			},
		}
		b, err := yaml.MarshalWithOptions(v, yaml.WithComment(
			yaml.CommentMap{
				"$.foo.bar":     []*yaml.Comment{yaml.HeadComment(" bar head comment"), yaml.LineComment(" bar line comment")},
				"$.foo.bar.baz": []*yaml.Comment{yaml.LineComment(" baz line comment")},
			},
		))
		if err != nil {
			t.Fatal(err)
		}
		expected := `
foo:
  # bar head comment
  bar: # bar line comment
    baz: true # baz line comment
`
		actual := "\n" + string(b)
		if expected != actual {
			t.Fatalf("expected:%s but got %s", expected, actual)
		}
	})
	t.Run("single head comment", func(t *testing.T) {
		v := struct {
			Foo string                 `yaml:"foo"`
			Bar map[string]interface{} `yaml:"bar"`
			Baz struct {
				X int `yaml:"x"`
			} `yaml:"baz"`
		}{
			Foo: "aaa",
			Bar: map[string]interface{}{"bbb": "ccc"},
			Baz: struct {
				X int `yaml:"x"`
			}{X: 10},
		}

		b, err := yaml.MarshalWithOptions(v, yaml.WithComment(
			yaml.CommentMap{
				"$.foo":     []*yaml.Comment{yaml.HeadComment("foo comment")},
				"$.bar":     []*yaml.Comment{yaml.HeadComment("bar comment")},
				"$.bar.bbb": []*yaml.Comment{yaml.HeadComment("bbb comment")},
				"$.baz.x":   []*yaml.Comment{yaml.HeadComment("x comment")},
			},
		))
		if err != nil {
			t.Fatal(err)
		}
		expected := `
#foo comment
foo: aaa
#bar comment
bar:
  #bbb comment
  bbb: ccc
baz:
  #x comment
  x: 10
`
		actual := "\n" + string(b)
		if expected != actual {
			t.Fatalf("expected:%s but got %s", expected, actual)
		}
	})

	t.Run("multiple head comment", func(t *testing.T) {
		v := struct {
			Foo string                 `yaml:"foo"`
			Bar map[string]interface{} `yaml:"bar"`
			Baz struct {
				X int `yaml:"x"`
			} `yaml:"baz"`
		}{
			Foo: "aaa",
			Bar: map[string]interface{}{"bbb": "ccc"},
			Baz: struct {
				X int `yaml:"x"`
			}{X: 10},
		}

		b, err := yaml.MarshalWithOptions(v, yaml.WithComment(
			yaml.CommentMap{
				"$.foo": []*yaml.Comment{
					yaml.HeadComment(
						"foo comment",
						"foo comment2",
					),
				},
				"$.bar": []*yaml.Comment{
					yaml.HeadComment(
						"bar comment",
						"bar comment2",
					),
				},
				"$.bar.bbb": []*yaml.Comment{
					yaml.HeadComment(
						"bbb comment",
						"bbb comment2",
					),
				},
				"$.baz.x": []*yaml.Comment{
					yaml.HeadComment(
						"x comment",
						"x comment2",
					),
				},
			},
		))
		if err != nil {
			t.Fatal(err)
		}
		expected := `
#foo comment
#foo comment2
foo: aaa
#bar comment
#bar comment2
bar:
  #bbb comment
  #bbb comment2
  bbb: ccc
baz:
  #x comment
  #x comment2
  x: 10
`
		actual := "\n" + string(b)
		if expected != actual {
			t.Fatalf("expected:%s but got %s", expected, actual)
		}
	})
	t.Run("foot comment", func(t *testing.T) {
		v := struct {
			Bar map[string]interface{} `yaml:"bar"`
			Baz []int                  `yaml:"baz"`
		}{
			Bar: map[string]interface{}{"bbb": "ccc"},
			Baz: []int{1, 2},
		}

		b, err := yaml.MarshalWithOptions(v, yaml.IndentSequence(true), yaml.WithComment(
			yaml.CommentMap{
				"$.bar.bbb": []*yaml.Comment{yaml.FootComment("ccc: ddd")},
				"$.baz[1]":  []*yaml.Comment{yaml.FootComment("- 3")},
				"$.baz":     []*yaml.Comment{yaml.FootComment(" foot comment", "foot comment2")},
			},
		))
		if err != nil {
			t.Fatal(err)
		}
		expected := `
bar:
  bbb: ccc
  #ccc: ddd
baz:
  - 1
  - 2
  #- 3
# foot comment
#foot comment2
`
		actual := "\n" + string(b)
		if expected != actual {
			t.Fatalf("expected:%s but got %s", expected, actual)
		}
	})

	t.Run("combination", func(t *testing.T) {
		v := struct {
			Foo  map[string]interface{} `yaml:"foo"`
			O    map[string]interface{} `yaml:"o"`
			T    map[string]bool        `yaml:"t"`
			Bar  map[string]interface{} `yaml:"bar"`
			Baz  []int                  `yaml:"baz"`
			Hoge map[string]interface{} `yaml:"hoge"`
		}{
			Foo: map[string]interface{}{
				"a": map[string]interface{}{
					"b": map[string]interface{}{
						"c": "d",
					},
				},
			},
			O: map[string]interface{}{
				"p": map[string]interface{}{
					"q": map[string]interface{}{
						"r": "s",
					},
				},
			},
			T: map[string]bool{
				"u": true,
			},
			Bar: map[string]interface{}{"bbb": "ccc"},
			Baz: []int{1, 2},
			Hoge: map[string]interface{}{
				"moga": true,
			},
		}

		b, err := yaml.MarshalWithOptions(v, yaml.IndentSequence(true), yaml.WithComment(
			yaml.CommentMap{
				"$.foo": []*yaml.Comment{
					yaml.HeadComment(" foo head comment", " foo head comment2"),
					yaml.LineComment(" foo line comment"),
				},
				"$.foo.a": []*yaml.Comment{
					yaml.HeadComment(" a head comment"),
					yaml.LineComment(" a line comment"),
				},
				"$.foo.a.b": []*yaml.Comment{
					yaml.HeadComment(" b head comment"),
					yaml.LineComment(" b line comment"),
				},
				"$.foo.a.b.c": []*yaml.Comment{
					yaml.LineComment(" c line comment"),
				},
				"$.o": []*yaml.Comment{
					yaml.LineComment(" o line comment"),
				},
				"$.o.p": []*yaml.Comment{
					yaml.HeadComment(" p head comment", " p head comment2"),
					yaml.LineComment(" p line comment"),
				},
				"$.o.p.q": []*yaml.Comment{
					yaml.HeadComment(" q head comment", " q head comment2"),
					yaml.LineComment(" q line comment"),
				},
				"$.o.p.q.r": []*yaml.Comment{
					yaml.LineComment(" r line comment"),
				},
				"$.t.u": []*yaml.Comment{
					yaml.LineComment(" u line comment"),
				},
				"$.bar": []*yaml.Comment{
					yaml.HeadComment(" bar head comment"),
					yaml.LineComment(" bar line comment"),
				},
				"$.bar.bbb": []*yaml.Comment{
					yaml.HeadComment(" bbb head comment"),
					yaml.LineComment(" bbb line comment"),
					yaml.FootComment(" bbb foot comment"),
				},
				"$.baz[0]": []*yaml.Comment{
					yaml.HeadComment(" sequence head comment"),
					yaml.LineComment(" sequence line comment"),
				},
				"$.baz[1]": []*yaml.Comment{
					yaml.HeadComment(" sequence head comment2"),
					yaml.LineComment(" sequence line comment2"),
					yaml.FootComment(" sequence foot comment"),
				},
				"$.baz": []*yaml.Comment{
					yaml.HeadComment(" baz head comment", " baz head comment2"),
					yaml.LineComment(" baz line comment"),
					yaml.FootComment(" baz foot comment"),
				},
				"$.hoge.moga": []*yaml.Comment{
					yaml.LineComment(" moga line comment"),
					yaml.FootComment(" moga foot comment"),
				},
			},
		))
		if err != nil {
			t.Fatal(err)
		}
		expected := `
# foo head comment
# foo head comment2
foo: # foo line comment
  # a head comment
  a: # a line comment
    # b head comment
    b: # b line comment
      c: d # c line comment
o: # o line comment
  # p head comment
  # p head comment2
  p: # p line comment
    # q head comment
    # q head comment2
    q: # q line comment
      r: s # r line comment
t:
  u: true # u line comment
# bar head comment
bar: # bar line comment
  # bbb head comment
  bbb: ccc # bbb line comment
  # bbb foot comment
# baz head comment
# baz head comment2
baz: # baz line comment
  # sequence head comment
  - 1 # sequence line comment
  # sequence head comment2
  - 2 # sequence line comment2
  # sequence foot comment
# baz foot comment
hoge:
  moga: true # moga line comment
  # moga foot comment
`
		actual := "\n" + string(b)
		if expected != actual {
			t.Fatalf("expected:%s but got %s", expected, actual)
		}
	})

}

func Test_CommentToMapOption(t *testing.T) {
	t.Run("line comment", func(t *testing.T) {
		yml := `
foo: aaa #foo comment
bar: #bar comment
  bbb: ccc #bbb comment
baz:
  x: 10 #x comment
`
		var (
			v  interface{}
			cm = yaml.CommentMap{}
		)
		if err := yaml.UnmarshalWithOptions([]byte(yml), &v, yaml.CommentToMap(cm)); err != nil {
			t.Fatal(err)
		}
		expected := []struct {
			path     string
			comments []*yaml.Comment
		}{
			{
				path:     "$.foo",
				comments: []*yaml.Comment{yaml.LineComment("foo comment")},
			},
			{
				path:     "$.bar",
				comments: []*yaml.Comment{yaml.LineComment("bar comment")},
			},
			{
				path:     "$.bar.bbb",
				comments: []*yaml.Comment{yaml.LineComment("bbb comment")},
			},
			{
				path:     "$.baz.x",
				comments: []*yaml.Comment{yaml.LineComment("x comment")},
			},
		}
		for _, exp := range expected {
			comments := cm[exp.path]
			if comments == nil {
				t.Fatalf("failed to get path %s", exp.path)
			}
			if diff := cmp.Diff(exp.comments, comments); diff != "" {
				t.Errorf("(-got, +want)\n%s", diff)
			}
		}
	})
	t.Run("line comment2", func(t *testing.T) {
		yml := `
foo:
  bar: baz # comment`
		var (
			v  interface{}
			cm = yaml.CommentMap{}
		)
		if err := yaml.UnmarshalWithOptions([]byte(yml), &v, yaml.CommentToMap(cm)); err != nil {
			t.Fatal(err)
		}
		expected := []struct {
			path     string
			comments []*yaml.Comment
		}{
			{
				path:     "$.foo.bar",
				comments: []*yaml.Comment{yaml.LineComment(" comment")},
			},
		}
		for _, exp := range expected {
			comments := cm[exp.path]
			if comments == nil {
				t.Fatalf("failed to get path %s", exp.path)
			}
			if diff := cmp.Diff(exp.comments, comments); diff != "" {
				t.Errorf("(-got, +want)\n%s", diff)
			}
		}
	})

	t.Run("single head comment", func(t *testing.T) {
		yml := `
#foo comment
foo: aaa
#bar comment
bar:
  #bbb comment
  bbb: ccc
baz:
  #x comment
  x: 10
`
		var (
			v  interface{}
			cm = yaml.CommentMap{}
		)
		if err := yaml.UnmarshalWithOptions([]byte(yml), &v, yaml.CommentToMap(cm)); err != nil {
			t.Fatal(err)
		}
		expected := []struct {
			path     string
			comments []*yaml.Comment
		}{
			{
				path:     "$.foo",
				comments: []*yaml.Comment{yaml.HeadComment("foo comment")},
			},
			{
				path:     "$.bar",
				comments: []*yaml.Comment{yaml.HeadComment("bar comment")},
			},
			{
				path:     "$.bar.bbb",
				comments: []*yaml.Comment{yaml.HeadComment("bbb comment")},
			},
			{
				path:     "$.baz.x",
				comments: []*yaml.Comment{yaml.HeadComment("x comment")},
			},
		}
		for _, exp := range expected {
			comments := cm[exp.path]
			if comments == nil {
				t.Fatalf("failed to get path %s", exp.path)
			}
			if diff := cmp.Diff(exp.comments, comments); diff != "" {
				t.Errorf("(-got, +want)\n%s", diff)
			}
		}
	})
	t.Run("multiple head comments", func(t *testing.T) {
		yml := `
#foo comment
#foo comment2
foo: aaa
#bar comment
#bar comment2
bar:
  #bbb comment
  #bbb comment2
  bbb: ccc
baz:
  #x comment
  #x comment2
  x: 10
`
		var (
			v  interface{}
			cm = yaml.CommentMap{}
		)
		if err := yaml.UnmarshalWithOptions([]byte(yml), &v, yaml.CommentToMap(cm)); err != nil {
			t.Fatal(err)
		}
		expected := []struct {
			path     string
			comments []*yaml.Comment
		}{
			{
				path: "$.foo",
				comments: []*yaml.Comment{
					yaml.HeadComment(
						"foo comment",
						"foo comment2",
					),
				},
			},
			{
				path: "$.bar",
				comments: []*yaml.Comment{
					yaml.HeadComment(
						"bar comment",
						"bar comment2",
					),
				},
			},
			{
				path: "$.bar.bbb",
				comments: []*yaml.Comment{
					yaml.HeadComment(
						"bbb comment",
						"bbb comment2",
					),
				},
			},
			{
				path: "$.baz.x",
				comments: []*yaml.Comment{
					yaml.HeadComment(
						"x comment",
						"x comment2",
					),
				},
			},
		}
		for _, exp := range expected {
			comments := cm[exp.path]
			if comments == nil {
				t.Fatalf("failed to get path %s", exp.path)
			}
			if diff := cmp.Diff(exp.comments, comments); diff != "" {
				t.Errorf("(-got, +want)\n%s", diff)
			}
		}
	})
	t.Run("foot comment", func(t *testing.T) {
		yml := `
bar:
  bbb: ccc
  #ccc: ddd
baz:
  - 1
  - 2
  #- 3
 # foot comment
#foot comment2
`
		var (
			v  interface{}
			cm = yaml.CommentMap{}
		)
		if err := yaml.UnmarshalWithOptions([]byte(yml), &v, yaml.CommentToMap(cm)); err != nil {
			t.Fatal(err)
		}
		expected := []struct {
			path     string
			comments []*yaml.Comment
		}{
			{
				path:     "$.bar.bbb",
				comments: []*yaml.Comment{yaml.FootComment("ccc: ddd")},
			},
			{
				path:     "$.baz[1]",
				comments: []*yaml.Comment{yaml.FootComment("- 3")},
			},
			{
				path:     "$.baz",
				comments: []*yaml.Comment{yaml.FootComment(" foot comment", "foot comment2")},
			},
		}
		for _, exp := range expected {
			comments := cm[exp.path]
			if comments == nil {
				t.Fatalf("failed to get path %s", exp.path)
			}
			if diff := cmp.Diff(exp.comments, comments); diff != "" {
				t.Errorf("(-got, +want)\n%s", diff)
			}
		}
	})
	t.Run("combination", func(t *testing.T) {
		yml := `
# foo head comment
# foo head comment2
foo: # foo line comment
  # a head comment
  a: # a line comment
    # b head comment
    b: # b line comment
      c: d # c line comment
o: # o line comment
  # p head comment
  # p head comment2
  p: # p line comment
    # q head comment
    # q head comment2
    q: # q line comment
      r: s # r line comment
t:
  u: true # u line comment
# bar head comment
bar: # bar line comment
  # bbb head comment
  bbb: ccc # bbb line comment
  # bbb foot comment
# baz head comment
# baz head comment2
baz: # baz line comment
  # sequence head comment
  - 1 # sequence line comment
  # sequence head comment2
  - 2 # sequence line comment2
  # sequence foot comment
hoge:
  moga: true # moga line comment
  # moga foot comment
# hoge foot comment
`
		var (
			v  interface{}
			cm = yaml.CommentMap{}
		)
		if err := yaml.UnmarshalWithOptions([]byte(yml), &v, yaml.CommentToMap(cm)); err != nil {
			t.Fatal(err)
		}
		expected := []struct {
			path     string
			comments []*yaml.Comment
		}{
			{
				path: "$.foo",
				comments: []*yaml.Comment{
					yaml.HeadComment(" foo head comment", " foo head comment2"),
					yaml.LineComment(" foo line comment"),
				},
			},
			{
				path: "$.foo.a",
				comments: []*yaml.Comment{
					yaml.HeadComment(" a head comment"),
					yaml.LineComment(" a line comment"),
				},
			},
			{
				path: "$.foo.a.b",
				comments: []*yaml.Comment{
					yaml.HeadComment(" b head comment"),
					yaml.LineComment(" b line comment"),
				},
			},
			{
				path: "$.foo.a.b.c",
				comments: []*yaml.Comment{
					yaml.LineComment(" c line comment"),
				},
			},
			{
				path: "$.o",
				comments: []*yaml.Comment{
					yaml.LineComment(" o line comment"),
				},
			},
			{
				path: "$.o.p",
				comments: []*yaml.Comment{
					yaml.HeadComment(" p head comment", " p head comment2"),
					yaml.LineComment(" p line comment"),
				},
			},
			{
				path: "$.o.p.q",
				comments: []*yaml.Comment{
					yaml.HeadComment(" q head comment", " q head comment2"),
					yaml.LineComment(" q line comment"),
				},
			},
			{
				path: "$.o.p.q.r",
				comments: []*yaml.Comment{
					yaml.LineComment(" r line comment"),
				},
			},
			{
				path: "$.t.u",
				comments: []*yaml.Comment{
					yaml.LineComment(" u line comment"),
				},
			},
			{
				path: "$.bar",
				comments: []*yaml.Comment{
					yaml.HeadComment(" bar head comment"),
					yaml.LineComment(" bar line comment"),
				},
			},
			{
				path: "$.bar.bbb",
				comments: []*yaml.Comment{
					yaml.HeadComment(" bbb head comment"),
					yaml.LineComment(" bbb line comment"),
					yaml.FootComment(" bbb foot comment"),
				},
			},
			{
				path: "$.baz[0]",
				comments: []*yaml.Comment{
					yaml.HeadComment(" sequence head comment"),
					yaml.LineComment(" sequence line comment"),
				},
			},
			{
				path: "$.baz[1]",
				comments: []*yaml.Comment{
					yaml.HeadComment(" sequence head comment2"),
					yaml.LineComment(" sequence line comment2"),
					yaml.FootComment(" sequence foot comment"),
				},
			},
			{
				path: "$.baz",
				comments: []*yaml.Comment{
					yaml.HeadComment(" baz head comment", " baz head comment2"),
					yaml.LineComment(" baz line comment"),
				},
			},
			{
				path: "$.hoge",
				comments: []*yaml.Comment{
					yaml.FootComment(" hoge foot comment"),
				},
			},
			{
				path: "$.hoge.moga",
				comments: []*yaml.Comment{
					yaml.LineComment(" moga line comment"),
					yaml.FootComment(" moga foot comment"),
				},
			},
		}
		for _, exp := range expected {
			comments := cm[exp.path]
			if comments == nil {
				t.Fatalf("failed to get path %s", exp.path)
			}
			if diff := cmp.Diff(exp.comments, comments); diff != "" {
				t.Errorf("%s: (-got, +want)\n%s", exp.path, diff)
			}
		}
	})
}

func TestRegisterCustomMarshaler(t *testing.T) {
	type T struct {
		Foo []byte `yaml:"foo"`
	}
	yaml.RegisterCustomMarshaler[T](func(_ T) ([]byte, error) {
		return []byte(`"override"`), nil
	})
	b, err := yaml.Marshal(&T{Foo: []byte("bar")})
	if err != nil {
		t.Fatal(err)
	}
	if !bytes.Equal(b, []byte("\"override\"\n")) {
		t.Fatalf("failed to register custom marshaler. got: %q", b)
	}
}

func TestRegisterCustomUnmarshaler(t *testing.T) {
	type T struct {
		Foo []byte `yaml:"foo"`
	}
	yaml.RegisterCustomUnmarshaler[T](func(v *T, _ []byte) error {
		v.Foo = []byte("override")
		return nil
	})
	var v T
	if err := yaml.Unmarshal([]byte(`"foo: "bar"`), &v); err != nil {
		t.Fatal(err)
	}
	if !bytes.Equal(v.Foo, []byte("override")) {
		t.Fatalf("failed to decode. got %q", v.Foo)
	}
}