Fix some linter error

Author: xynicole

lex.go

@@ -44,10 +44,15 @@ func SetTokenChanCap(size int) {
 	tokChanCap = size
 }
 
+// LexScanner provides an interface for scanning tokens.
 type LexScanner interface {
+	// Scan is used to advance the scanner to the next token.
 	Scan() bool
+	// Err returns any error encountered during scanning.
 	Err() error
+	// Text returns the most recent token generated by Scan as a string.
 	Text() string
+	// Line returns the line number of the most recent token generated by Scan.
 	Line() int
 }
 
@@ -164,7 +169,6 @@ func tokenize(reader io.Reader, tokenCh chan NgxToken, options LexOptions) {
 			la = "\\" + la
 		}
 
-		// special handling for *_by_lua_block directives
 		if token.Len() > 0 {
 			tokenStr := token.String()
 			if ext, ok := externalLexers[tokenStr]; ok {
@@ -357,8 +361,8 @@ func (ll *LuaLexer) Lex(matchedToken string) <-chan NgxToken {
 		var inQuotes bool
 
 		// special handling for'set_by_lua_block' directive
-		// #nosec G101
-		if matchedToken == "set_by_lua_block" { //nolint
+		// ignore Potential hardcoded credentials linter warning for "set_by_lua_block"
+		if matchedToken == "set_by_lua_block" /* #nosec G101 */ {
 			arg := ""
 			for {
 				if !ll.s.Scan() {
@@ -380,22 +384,23 @@ func (ll *LuaLexer) Lex(matchedToken string) <-chan NgxToken {
 				}
 				arg += next
 			}
-			// skip leading whitespace after the return value
-			for {
-				if !ll.s.Scan() {
-					return
-				}
-				next := ll.s.Text()
+		}
 
-				if !isSpace(next) {
-					if next != "{" {
-						lineno := ll.s.Line()
-						tokenCh <- NgxToken{Error: &ParseError{File: &lexerFile, What: `unexpected "}"`, Line: &lineno}}
-						return
-					}
-					tokenDepth++
-					break
+		// skip leading whitespace after the return value
+		for {
+			if !ll.s.Scan() {
+				return
+			}
+			next := ll.s.Text()
+
+			if !isSpace(next) {
+				if next != "{" {
+					lineno := ll.s.Line()
+					tokenCh <- NgxToken{Error: &ParseError{File: &lexerFile, What: `expected "{" to start lua block`, Line: &lineno}}
+					return
 				}
+				tokenDepth++
+				break
 			}
 		}