Refactor logger to support multiple output writers and disable stdout

main.go

@@ -4,7 +4,6 @@ import (
 	"bytes"
 	"flag"
 	"fmt"
-	"github.com/hexops/valast"
 	"io"
 	"log"
 	"os"
@@ -14,6 +13,8 @@ import (
 	"strings"
 	"sync"
 	"time"
+
+	"github.com/hexops/valast"
 )
 
 // TODO: Enable turning colors on and off maybe even per stream?
@@ -97,7 +98,7 @@ var levelStyles = map[LogLevel]LevelStyle{
 // Logger is our custom logger with level support
 type Logger struct {
 	mu            sync.Mutex
-	out           io.Writer
+	out           []io.Writer
 	currentLevel  LogLevel
 	prefix        string
 	userPrefix    string
@@ -150,7 +151,7 @@ func (l LogLevel) String() string {
 // New creates a new Logger instance
 func New(out io.Writer, prefix string, flag int) *Logger {
 	return &Logger{
-		out:           out,
+		out:           []io.Writer{out},
 		currentLevel:  defaultLogLevel,
 		prefix:        prefix,
 		userPrefix:    "",
@@ -216,7 +217,7 @@ func (l *Logger) ShowGoroutine() bool {
 // WithField adds a field to the logger's context
 func (l *Logger) WithField(key string, value interface{}) *Logger {
 	newLogger := &Logger{
-		out:           l.out,
+		out:           append([]io.Writer(nil), l.out...),
 		currentLevel:  l.currentLevel,
 		prefix:        l.prefix,
 		userPrefix:    l.userPrefix,
@@ -240,7 +241,7 @@ func (l *Logger) WithField(key string, value interface{}) *Logger {
 // WithFields adds multiple fields to the logger's context
 func (l *Logger) WithFields(fields map[string]interface{}) *Logger {
 	newLogger := &Logger{
-		out:           l.out,
+		out:           append([]io.Writer(nil), l.out...),
 		currentLevel:  l.currentLevel,
 		prefix:        l.prefix,
 		userPrefix:    l.userPrefix,
@@ -271,7 +272,7 @@ func (l *Logger) WithPrefix(prefix string) *Logger {
 		l = Default
 	}
 	newLogger := &Logger{
-		out:           l.out,
+		out:           append([]io.Writer(nil), l.out...),
 		currentLevel:  l.currentLevel,
 		prefix:        l.prefix,
 		userPrefix:    strings.TrimSpace(l.userPrefix + " " + prefix),
@@ -301,7 +302,7 @@ func (l *Logger) ToFile(filename string) *Logger {
 		l = Default
 	}
 	newLogger := &Logger{
-		out:           io.MultiWriter(l.out, file),
+		out:           append([]io.Writer(nil), l.out...),
 		currentLevel:  l.currentLevel,
 		prefix:        l.prefix,
 		userPrefix:    l.userPrefix,
@@ -311,6 +312,12 @@ func (l *Logger) ToFile(filename string) *Logger {
 		defaultFields: make(map[string]interface{}),
 		showGoroutine: l.showGoroutine,
 	}
+	// Copy existing fields
+	for k, v := range l.defaultFields {
+		newLogger.defaultFields[k] = v
+	}
+	// Append the new file writer
+	newLogger.out = append(newLogger.out, file)
 	return newLogger
 }
 
@@ -488,7 +495,9 @@ func (l *Logger) log(level LogLevel, format string, args ...interface{}) {
 
 	// Get formatted message with potential background color
 	msg := l.formatMessage(level, format, args...)
-	fmt.Fprintln(l.out, msg)
+	for _, w := range l.out {
+		fmt.Fprintln(w, msg)
+	}
 }
 
 // Error logs an error message
@@ -659,6 +668,38 @@ func ShowGoroutine() bool {
 	return Default.ShowGoroutine()
 }
 
+func (l *Logger) NoStdout() *Logger {
+	if Default == nil {
+		Init(defaultLogLevel)
+	}
+	if l == nil {
+		l = Default
+	}
+	newLogger := &Logger{
+		out:           nil,
+		currentLevel:  l.currentLevel,
+		prefix:        l.prefix,
+		userPrefix:    l.userPrefix,
+		flag:          l.flag,
+		useColors:     l.useColors,
+		callerOffset:  l.callerOffset,
+		defaultFields: make(map[string]interface{}),
+		showGoroutine: l.showGoroutine,
+	}
+	// Copy existing fields
+	for k, v := range l.defaultFields {
+		newLogger.defaultFields[k] = v
+	}
+	// Keep all writers except stdout
+	for _, w := range l.out {
+		if w == os.Stdout {
+			continue
+		}
+		newLogger.out = append(newLogger.out, w)
+	}
+	return newLogger
+}
+
 func main() {
 	Init(LevelDebug)