test log level and add some unit test case

log/level_test.go

@@ -1,6 +1,8 @@
 package log
 
 import (
+	"encoding/json"
+	"os"
 	"testing"
 )
 
@@ -16,4 +18,33 @@ func TestGetLevel(t *testing.T) {
 	if num != 7 {
 		t.Errorf("defaultLogLevel set failed: %d\n", num)
 	}
+
+	initLogLevel("error")
+	Debug("my book is bought in the year of ", 2016)
+	Info("this %s cat is %v years old", "yellow", 3)
+	Notice("Notice log")
+	Warn("json is a type of kv like", map[string]int{"key": 2016})
+	Error("error log")
+	Critical("critical log")
+	Alert("alert log")
+	Emergency("emergency log")
+}
+
+func initLogLevel(level string) {
+	fileName := "/tmp/test.log"
+
+	logConf := struct {
+		FileName string `json:"filename"`
+		Level    int    `json:"level"`
+	}{
+		FileName: fileName,
+		Level:    GetLevel(level),
+	}
+
+	configuration, err := json.Marshal(logConf)
+	if err != nil {
+		panic(err)
+	}
+	Init(string(configuration))
+	os.Remove(fileName)
 }