modernize some code

clidocstool.go

@@ -174,7 +174,7 @@ func copyFile(src string, dst string) error {
 func getAliases(cmd *cobra.Command) []string {
 	if a := cmd.Annotations["aliases"]; a != "" {
 		aliases := strings.Split(a, ",")
-		for i := 0; i < len(aliases); i++ {
+		for i := range aliases {
 			aliases[i] = strings.TrimSpace(aliases[i])
 		}
 		return aliases

clidocstool_md.go

@@ -110,10 +110,10 @@ func (c *Client) GenMarkdownTree(cmd *cobra.Command) error {
 
 	cs := string(content)
 
-	start := strings.Index(cs, "<!---MARKER_GEN_START-->")
+	before, _, ok := strings.Cut(cs, "<!---MARKER_GEN_START-->")
 	end := strings.Index(cs, "<!---MARKER_GEN_END-->")
 
-	if start == -1 {
+	if !ok {
 		return fmt.Errorf("no start marker in %s", mdFile)
 	}
 	if end == -1 {
@@ -124,7 +124,7 @@ func (c *Client) GenMarkdownTree(cmd *cobra.Command) error {
 	if err != nil {
 		return err
 	}
-	cont := cs[:start] + "<!---MARKER_GEN_START-->" + "\n" + out + "\n" + cs[end:]
+	cont := before + "<!---MARKER_GEN_START-->" + "\n" + out + "\n" + cs[end:]
 
 	fi, err := os.Stat(targetPath)
 	if err != nil {

markdown.go

@@ -74,7 +74,7 @@ func cleanupMarkDown(mdString string) (md string, anchors []string) {
 	var id string
 	// replace trailing whitespace per line, and handle custom anchors
 	lines := strings.Split(mdString, "\n")
-	for i := 0; i < len(lines); i++ {
+	for i := range lines {
 		lines[i] = strings.TrimRightFunc(lines[i], unicode.IsSpace)
 		lines[i], id = convertHTMLAnchor(lines[i])
 		if id != "" {

markdown_test.go

@@ -101,7 +101,6 @@ Last line.`,
 		},
 	}
 	for _, tc := range tests {
-		tc := tc
 		t.Run(tc.doc, func(t *testing.T) {
 			out, _ := cleanupMarkDown(tc.in)
 			if out != tc.expected {
@@ -147,7 +146,6 @@ func TestConvertHTMLAnchor(t *testing.T) {
 		},
 	}
 	for _, tc := range tests {
-		tc := tc
 		t.Run(tc.in, func(t *testing.T) {
 			out, id := convertHTMLAnchor(tc.in)
 			if id != tc.id {