added ability to set external logger and fatal log methods

Author: jeevatkm

default.go

@@ -4,8 +4,22 @@
 
 package log
 
+import "os"
+
 var stdLogger Logger
 
+// Fatal logs message as `FATAL` and calls os.Exit(1)
+func Fatal(v ...interface{}) {
+	_ = stdLogger.Output(levelFatal, 2, nil, v...)
+	os.Exit(1)
+}
+
+// Fatalf logs message as `FATAL` and calls os.Exit(1)
+func Fatalf(format string, v ...interface{}) {
+	_ = stdLogger.Output(levelFatal, 2, &format, v...)
+	os.Exit(1)
+}
+
 // Error logs message as `LevelError`
 func Error(v ...interface{}) {
 	_ = stdLogger.Output(LevelError, 2, nil, v...)
@@ -72,6 +86,12 @@ func SetLevel(level Level) {
 	stdLogger.SetLevel(level)
 }
 
+// SetOutput allows to set standard logger implementation
+// which statisfies `Logger` interface
+func SetOutput(logger Logger) {
+	stdLogger = logger
+}
+
 func init() {
 	stdLogger, _ = New(`receiver = "CONSOLE"; level = "DEBUG";`)
 }

default_test.go

@@ -0,0 +1,42 @@
+// Copyright (c) Jeevanandam M (https://github.com/jeevatkm)
+// go-aah/log source code and usage is governed by a MIT style
+// license that can be found in the LICENSE file.
+
+package log
+
+import (
+	"fmt"
+	"testing"
+
+	"github.com/go-aah/test/assert"
+)
+
+func TestDefaultStandardLogger(t *testing.T) {
+	SetLevel(LevelInfo)
+	_ = SetPattern("%time:2006-01-02 15:04:05.000 %level:-5 %line %custom:- %message")
+	Trace("I shoudn't see this msg, because standard logger level is DEBUG")
+	Debug("I would like to see this message, debug is useful for dev")
+	Info("Yes, I would love to")
+	Warn("Yes, yes it's an warning")
+	Error("Yes, yes, yes - finally an error")
+	fmt.Println()
+
+	t.Logf("First round: %#v\n\n", Stats())
+
+	SetLevel(LevelDebug)
+	_ = SetPattern("%time:2006-01-02 15:04:05.000 %level:-5 %shortfile %line %custom:- %message")
+	Tracef("I shoudn't see this msg: %v", 4)
+	Debugf("I would like to see this message, debug is useful for dev: %v", 3)
+	Infof("Yes, I would love to: %v", 2)
+	Warnf("Yes, yes it's an warning: %v", 1)
+	Errorf("Yes, yes, yes - finally an error: %v", 0)
+
+	t.Logf("Second round: %#v\n\n", Stats())
+
+	err := SetPattern("%level:-5 %shortfile %line %unknown")
+	assert.NotNil(t, err)
+
+	newLogger, _ := New(`receiver = "CONSOLE"; level = "DEBUG";`)
+	SetOutput(newLogger)
+	Info("Fresh new face ...")
+}

log.go

@@ -22,6 +22,7 @@ import (
 	"os"
 	"runtime"
 	"strings"
+	"sync"
 	"time"
 
 	"github.com/go-aah/config"
@@ -36,7 +37,8 @@ type FmtFlag uint8
 
 // Log Level definition
 const (
-	LevelError Level = iota
+	levelFatal Level = iota
+	LevelError
 	LevelWarn
 	LevelInfo
 	LevelDebug
@@ -102,6 +104,7 @@ var (
 	filePermission     = os.FileMode(0755)
 
 	levelNameToLevel = map[string]Level{
+		"FATAL": levelFatal,
 		"ERROR": LevelError,
 		"WARN":  LevelWarn,
 		"INFO":  LevelInfo,
@@ -110,6 +113,7 @@ var (
 	}
 
 	levelToLevelName = map[Level]string{
+		levelFatal: "FATAL",
 		LevelError: "ERROR",
 		LevelWarn:  "WARN",
 		LevelInfo:  "INFO",
@@ -120,6 +124,7 @@ var (
 	// ANSI color codes
 	resetColor   = []byte("\033[0m")
 	levelToColor = [][]byte{
+		levelFatal: []byte("\033[0;31m"), // red
 		LevelError: []byte("\033[0;31m"), // red
 		LevelWarn:  []byte("\033[0;33m"), // yellow
 		LevelInfo:  []byte("\033[0;37m"), // white
@@ -162,6 +167,9 @@ type Logger interface {
 	// SetLevel allows to set log level dynamically
 	SetLevel(level Level)
 
+	Fatal(v ...interface{})
+	Fatalf(format string, v ...interface{})
+
 	Error(v ...interface{})
 	Errorf(format string, v ...interface{})
 
@@ -260,6 +268,7 @@ func newConsoleReceiver(cfg *config.Config, receiverType string, level Level, fl
 		Type:       receiverType,
 		Flags:      flags,
 		Format:     DefaultFormatter,
+		m:          sync.Mutex{},
 		level:      level,
 		out:        os.Stderr,
 		stats:      &ReceiverStats{},

log_test.go

@@ -5,7 +5,6 @@
 package log
 
 import (
-	"fmt"
 	"os"
 	"path/filepath"
 	"strings"
@@ -14,32 +13,6 @@ import (
 	"github.com/go-aah/test/assert"
 )
 
-func TestDefaultStandardLogger(t *testing.T) {
-	SetLevel(LevelInfo)
-	_ = SetPattern("%time:2006-01-02 15:04:05.000 %level:-5 %line %custom:- %message")
-	Trace("I shoudn't see this msg, because standard logger level is DEBUG")
-	Debug("I would like to see this message, debug is useful for dev")
-	Info("Yes, I would love to")
-	Warn("Yes, yes it's an warning")
-	Error("Yes, yes, yes - finally an error")
-	fmt.Println()
-
-	t.Logf("First round: %#v\n\n", Stats())
-
-	SetLevel(LevelDebug)
-	_ = SetPattern("%time:2006-01-02 15:04:05.000 %level:-5 %shortfile %line %custom:- %message")
-	Tracef("I shoudn't see this msg: %v", 4)
-	Debugf("I would like to see this message, debug is useful for dev: %v", 3)
-	Infof("Yes, I would love to: %v", 2)
-	Warnf("Yes, yes it's an warning: %v", 1)
-	Errorf("Yes, yes, yes - finally an error: %v", 0)
-
-	t.Logf("Second round: %#v\n\n", Stats())
-
-	err := SetPattern("%level:-5 %shortfile %line %unknown")
-	assert.NotNil(t, err)
-}
-
 func TestNewCustomUTCConsoleReceiver(t *testing.T) {
 	config := `
 # console logger configuration
@@ -302,7 +275,7 @@ func TestNewMisc(t *testing.T) {
 
 func TestLevelUnknown(t *testing.T) {
 	var level Level
-	assert.Equal(t, "ERROR", level.String())
+	assert.Equal(t, "FATAL", level.String())
 
 	level = 9 // Unknown log level
 	assert.Equal(t, "Unknown", level.String())

receiver.go

@@ -154,6 +154,18 @@ func (r *Receiver) isFileReceiver() bool {
 	return r.Type == "FILE"
 }
 
+// Fatal logs message as `FATAL` and calls os.Exit(1)
+func (r *Receiver) Fatal(v ...interface{}) {
+	_ = r.Output(levelFatal, 2, nil, v...)
+	os.Exit(1)
+}
+
+// Fatalf logs message as `FATAL` and calls os.Exit(1)
+func (r *Receiver) Fatalf(format string, v ...interface{}) {
+	_ = r.Output(levelFatal, 2, &format, v...)
+	os.Exit(1)
+}
+
 // Error logs message as `LevelError`
 func (r *Receiver) Error(v ...interface{}) {
 	_ = r.Output(LevelError, 2, nil, v...)