Replace hardcoded '2' in Output with const CallDepth

A `const CallDepth` placeholder has been introduced and has been set to 2. This is used as an argument in Output method calls in various log levels like debug, info, warn, and error in place of previously hardcoded '2'. This change improves the readability of the code. The '2' represented the call depth of log.Logger's Output method, which wasn't immediately clear with the hardcoded value.

log/stdlog.go

@@ -33,6 +33,10 @@ const (
 	LevelDebug
 )
 
+// CallDepth is the call depth value for the log.Logger's Output method
+// This defaults to 2 and is only here for better readablity of the code
+const CallDepth = 2
+
 // New returns a new Stdlog type that satisfies the Logger interface
 func New(o io.Writer, l Level) *Stdlog {
 	lf := log.Lmsgprefix | log.LstdFlags
@@ -48,27 +52,27 @@ func New(o io.Writer, l Level) *Stdlog {
 // Debugf performs a Printf() on the debug logger
 func (l *Stdlog) Debugf(f string, v ...interface{}) {
 	if l.l >= LevelDebug {
-		_ = l.debug.Output(2, fmt.Sprintf(f, v...))
+		_ = l.debug.Output(CallDepth, fmt.Sprintf(f, v...))
 	}
 }
 
 // Infof performs a Printf() on the info logger
 func (l *Stdlog) Infof(f string, v ...interface{}) {
 	if l.l >= LevelInfo {
-		_ = l.info.Output(2, fmt.Sprintf(f, v...))
+		_ = l.info.Output(CallDepth, fmt.Sprintf(f, v...))
 	}
 }
 
 // Warnf performs a Printf() on the warn logger
 func (l *Stdlog) Warnf(f string, v ...interface{}) {
 	if l.l >= LevelWarn {
-		_ = l.warn.Output(2, fmt.Sprintf(f, v...))
+		_ = l.warn.Output(CallDepth, fmt.Sprintf(f, v...))
 	}
 }
 
 // Errorf performs a Printf() on the error logger
 func (l *Stdlog) Errorf(f string, v ...interface{}) {
 	if l.l >= LevelError {
-		_ = l.err.Output(2, fmt.Sprintf(f, v...))
+		_ = l.err.Output(CallDepth, fmt.Sprintf(f, v...))
 	}
 }