chore(debug): add ability to override the debugPrint statement (#2337)

* feat: add ability to override the debugPrint statement

This allows users to use a single logger within their application for all printing, regardless of level.

* chore: make the code more readable, as per review comment

* fix: use tab instead of space for indentation

debug.go

@@ -23,6 +23,9 @@ func IsDebugging() bool {
 // DebugPrintRouteFunc indicates debug log output format.
 var DebugPrintRouteFunc func(httpMethod, absolutePath, handlerName string, nuHandlers int)
 
+// DebugPrintFunc indicates debug log output format.
+var DebugPrintFunc func(format string, values ...interface{})
+
 func debugPrintRoute(httpMethod, absolutePath string, handlers HandlersChain) {
 	if IsDebugging() {
 		nuHandlers := len(handlers)
@@ -48,12 +51,19 @@ func debugPrintLoadTemplate(tmpl *template.Template) {
 }
 
 func debugPrint(format string, values ...any) {
-	if IsDebugging() {
-		if !strings.HasSuffix(format, "\n") {
-			format += "\n"
-		}
-		fmt.Fprintf(DefaultWriter, "[GIN-debug] "+format, values...)
+	if !IsDebugging() {
+		return
+	}
+
+	if DebugPrintFunc != nil {
+		DebugPrintFunc(format, values...)
+		return
+	}
+
+	if !strings.HasSuffix(format, "\n") {
+		format += "\n"
 	}
+	fmt.Fprintf(DefaultWriter, "[GIN-debug] "+format, values...)
 }
 
 func getMinVer(v string) (uint64, error) {