Support WithComment option

[goccy]

Add option for encoding with comment .

Please see the following test case .

go-yaml/yaml_test.go

Lines 386 to 468 in 3c954f0

	func Test_WithCommentOption(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},
	}
	t.Run("line comment", func(t *testing.T) {
	b, err := yaml.MarshalWithOptions(v, yaml.WithComment(
	yaml.CommentMap{
	"$.foo": yaml.LineComment("foo comment"),
	"$.bar": yaml.LineComment("bar comment"),
	"$.bar.bbb": yaml.LineComment("bbb comment"),
	"$.baz.x": 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("head comment", func(t *testing.T) {
	b, err := yaml.MarshalWithOptions(v, yaml.WithComment(
	yaml.CommentMap{
	"$.foo": yaml.HeadComment(
	"foo comment",
	"foo comment2",
	),
	"$.bar": yaml.HeadComment(
	"bar comment",
	"bar comment2",
	),
	"$.bar.bbb": yaml.HeadComment(
	"bbb comment",
	"bbb comment2",
	),
	"$.baz.x": 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)
	}
	})
	}

yaml.WithComment is a option for encoding with comment .
The position where you want to add a comment is represented by YAMLPath, and it is the key of yaml.CommentMap .
Also, you can select Head comment or Line comment as the comment type.

[codecov-commenter]

Codecov Report

Merging #238 (225a4d7) into master (cc0aeb9) will decrease coverage by 0.47%.
The diff coverage is 52.45%.

@@            Coverage Diff             @@
##           master     #238      +/-   ##
==========================================
- Coverage   78.84%   78.37%   -0.48%     
==========================================
  Files          12       12              
  Lines        3356     3417      +61     
==========================================
+ Hits         2646     2678      +32     
- Misses        482      505      +23     
- Partials      228      234       +6     

[nakabonne]

I know it's quite tedious to extract comments from the AST so one vote for this option. I have no opportunity to add comments when encoding for now though.