add log channel

logger.go

@@ -6,6 +6,7 @@ import (
 	"log"
 	"os"
 	"sync"
+	"time"
 )
 
 type Level int
@@ -22,12 +23,19 @@ const (
 	prefixFatal = "FATAL: "
 )
 
+type LogEntry struct {
+	Timestamp time.Time
+	Level     Level
+	Message   string
+}
+
 type Logger struct {
 	infoLog  *log.Logger
 	errorLog *log.Logger
 	fatalLog *log.Logger
 	mu       sync.Mutex
 	verbose  bool
+	channel  chan LogEntry
 }
 
 // Init loggers for each log levels
@@ -42,6 +50,13 @@ func New(verbose bool) *Logger {
 	return &l
 }
 
+// Sets the output to a channel
+func (l *Logger) SetOutputChannel(c chan LogEntry) {
+	l.mu.Lock()
+	defer l.mu.Unlock()
+	l.channel = c
+}
+
 // Sets the output destination for the loggers
 // By default destination is stdout, you can change that
 // with this function
@@ -81,15 +96,27 @@ func (l *Logger) output(level Level, msg string) {
 
 func (l *Logger) Info(format string, v ...interface{}) {
 	if l.verbose {
-		l.output(INFO, fmt.Sprintf(format, v...))
+		if l.channel != nil {
+			l.channel <- LogEntry{Timestamp: time.Now(), Level: INFO, Message: fmt.Sprintf(format, v...)}
+		} else {
+			l.output(INFO, fmt.Sprintf(format, v...))
+		}
 	}
 }
 
 func (l *Logger) Error(format string, v ...interface{}) {
-	l.output(ERROR, fmt.Sprintf(format, v...))
+	if l.channel != nil {
+		l.channel <- LogEntry{Timestamp: time.Now(), Level: ERROR, Message: fmt.Sprintf(format, v...)}
+	} else {
+		l.output(ERROR, fmt.Sprintf(format, v...))
+	}
 }
 
 func (l *Logger) Fatal(v ...interface{}) {
-	l.output(FATAL, fmt.Sprint(v...))
-	os.Exit(1)
+	if l.channel != nil {
+		l.channel <- LogEntry{Timestamp: time.Now(), Level: FATAL, Message: fmt.Sprint(v...)}
+	} else {
+		l.output(FATAL, fmt.Sprint(v...))
+		os.Exit(1)
+	}
 }

logger_test.go

@@ -9,6 +9,41 @@ import (
 
 const Pattern_ts = `\d{4}/\d{2}/\d{2} \d{2}:\d{2}:\d{2}.\d{6} `
 
+func TestLoggerWithChannel(t *testing.T) {
+	// Create channel
+	logChannel := make(chan LogEntry, 10)
+
+	// Create logger
+	lg := New(true)
+	lg.SetOutputChannel((logChannel))
+
+	// logs messages
+	lg.Info("This is an informational message.")
+	lg.Error("This is an error message.")
+	lg.Fatal("This is a fatal message.")
+
+	// Expected entries
+	expectedEntries := []LogEntry{
+		{Level: INFO, Message: "This is an informational message."},
+		{Level: ERROR, Message: "This is an error message."},
+		{Level: FATAL, Message: "This is a fatal message."},
+	}
+
+	for i, expectedEntry := range expectedEntries {
+		select {
+		case entry := <-logChannel:
+			if entry.Level != expectedEntry.Level || entry.Message != expectedEntry.Message {
+				t.Errorf("Test case %d: Unexpected log entry. Got: %+v, Expected: %+v", i+1, entry, expectedEntry)
+			}
+		default:
+			t.Errorf("Test case %d: No log entry received from the channel.", i+1)
+		}
+	}
+
+	// cleanup
+	close(logChannel)
+}
+
 func TestLogInfo(t *testing.T) {
 	// prepare a buffer instead of stdout and a string to search
 	const msg = "hello world"