refactor Reflinker to reuse for all release notes

changelog.go

@@ -54,6 +54,7 @@ func (cl *ChangeLog) Generate(rels []*github.RepositoryRelease) error {
 
 	out := bufio.NewWriter(cl.out)
 	heading := strings.Repeat("#", cl.level)
+	linker := NewReflinker(cl.repoURL)
 
 	numRels := len(rels)
 	relLinks := make([]link, 0, numRels)
@@ -99,7 +100,7 @@ func (cl *ChangeLog) Generate(rels []*github.RepositoryRelease) error {
 		}
 
 		fmt.Fprintf(out, "%s [%s](%s) - %s\n\n", heading, title, pageURL, created.Format("02 Jan 2006"))
-		fmt.Fprint(out, LinkRefs(strings.Replace(rel.GetBody(), "\r", "", -1), cl.repoURL))
+		fmt.Fprint(out, linker.Link(strings.Replace(rel.GetBody(), "\r", "", -1)))
 		fmt.Fprintf(out, "\n\n[Changes][%s]\n\n\n", tag)
 
 		relLinks = append(relLinks, link{tag, compareURL})

reflink.go

@@ -66,23 +66,26 @@ type Reflinker struct {
 
 // NewReflinker creates Reflinker instance. repoURL is a repository URL of the service like
 // https://github.com/user/repo.
-func NewReflinker(repoURL string, src []byte) *Reflinker {
+func NewReflinker(repoURL string) *Reflinker {
 	u, err := url.Parse(repoURL)
 	if err != nil {
 		panic(err)
 	}
 	u.Path = ""
 
 	l := &Reflinker{
-		repo:  repoURL,
-		home:  u.String(),
-		src:   src,
-		links: nil,
+		repo: repoURL,
+		home: u.String(),
 	}
 	l.AddExtRef("GH-", repoURL+"/issues/<num>", false)
 	return l
 }
 
+func (l *Reflinker) reset(src []byte) {
+	l.src = src
+	l.links = nil
+}
+
 func (l *Reflinker) isBoundaryAt(idx int) bool {
 	if idx < 0 || len(l.src) <= idx {
 		return true
@@ -371,11 +374,7 @@ func (l *Reflinker) linkURL(n *ast.AutoLink) {
 	}
 }
 
-// BuildLinkedText builds a markdown text linking all references.
-func (l *Reflinker) BuildLinkedText() string {
-	if len(l.links) == 0 {
-		return string(l.src)
-	}
+func (l *Reflinker) buildLinkedText() string {
 	sort.Sort(byStart(l.links))
 
 	var b strings.Builder
@@ -389,17 +388,16 @@ func (l *Reflinker) BuildLinkedText() string {
 	return b.String()
 }
 
-// IsLinkDetected returns whether one or more links were detected.
-func (l *Reflinker) IsLinkDetected() bool {
+func (l *Reflinker) isLinkDetected() bool {
 	return len(l.links) > 0
 }
 
-// LinkRefs replaces all references in the given markdown text with actual links.
-func LinkRefs(input string, repoURL string) string {
+// Link replaces all references in the given markdown text with actual links.
+func (l *Reflinker) Link(input string) string {
 	src := []byte(input)
 	md := goldmark.New(goldmark.WithExtensions(extension.GFM))
 	t := md.Parser().Parse(text.NewReader(src))
-	l := NewReflinker(repoURL, src)
+	l.reset(src)
 
 	ast.Walk(t, func(n ast.Node, entering bool) (ast.WalkStatus, error) {
 		if !entering {
@@ -421,9 +419,9 @@ func LinkRefs(input string, repoURL string) string {
 		}
 	})
 
-	if !l.IsLinkDetected() {
+	if !l.isLinkDetected() {
 		return input
 	}
 
-	return l.BuildLinkedText()
+	return l.buildLinkedText()
 }

reflink_test.go

@@ -570,7 +570,8 @@ func TestLinkRefs(t *testing.T) {
 			if tc.repoURL != "" {
 				u = tc.repoURL
 			}
-			have := LinkRefs(tc.input, u)
+			l := NewReflinker(u)
+			have := l.Link(tc.input)
 			if have != tc.want {
 				t.Fatalf("wanted %q but got %q", tc.want, have)
 			}