add support for format

format.go

@@ -2,13 +2,21 @@ package gologger
 
 import (
 	"fmt"
+	"strings"
 )
 
 const logTemplate = "[%s] %s : %s - %s\n"
 
 func format(logEvent LogEvent) string {
 	data := logEvent.Ts.Format("2006-01-02 15:04:05")
-	msg := fmt.Sprint(logEvent.Data...)
+	msg := ""
+	firstMsg := logEvent.Data[0]
+	if isFormatString(firstMsg) {
+		msg = fmt.Sprintf(firstMsg.(string), logEvent.Data[1:]...)
+	} else {
+		msg = sprint(logEvent.Data)
+	}
+
 	ret := fmt.Sprintf(logTemplate, data, logEvent.Category, getLogLevelStr(logEvent.Level), msg)
 	return ret
 }
@@ -16,8 +24,30 @@ func format(logEvent LogEvent) string {
 func getLogLevelStr(level int) string {
 	for name, slevel := range logLevelMap {
 		if slevel == level {
-			return name
+			return strings.ToUpper(name)
 		}
 	}
 	return "Unknown"
 }
+
+func isFormatString(f interface{}) bool {
+	s, ok := f.(string)
+	if !ok {
+		return false
+	}
+	// 尝试使用空接口来格式化字符串
+	m := fmt.Sprintf(s, []interface{}{})
+	return strings.Index(m, "MISSING") != -1
+}
+
+func sprint(s []interface{}) string {
+	str := make([]any, len(s))
+	for i, v := range s {
+		if i > 0 {
+			str[i] = fmt.Sprintf(" %v", v)
+		} else {
+			str[i] = fmt.Sprintf("%v", v)
+		}
+	}
+	return fmt.Sprint(str...)
+}

format_test.go

@@ -0,0 +1,44 @@
+package gologger
+
+import (
+	"strings"
+	"testing"
+	"time"
+)
+
+func TestFormat(t *testing.T) {
+	tests := []struct {
+		name     string
+		logEvent LogEvent
+		want     string
+	}{
+		{
+			name: "Info level with format string",
+			logEvent: LogEvent{
+				Ts:       time.Now(),
+				Category: "test_category",
+				Level:    Info,
+				Data:     []interface{}{"%s: %v", "key", "value"},
+			},
+			want: "test_category : INFO - key: value",
+		},
+		{
+			name: "Error level without format string",
+			logEvent: LogEvent{
+				Ts:       time.Now(),
+				Category: "test_category",
+				Level:    Error,
+				Data:     []interface{}{"error occurred", "additional info"},
+			},
+			want: "test_category : ERROR - error occurred additional info",
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			if got := format(tt.logEvent); strings.Index(got, tt.want) == -1 {
+				t.Errorf("format() = %v, want %v", got, tt.want)
+			}
+		})
+	}
+}