Feature: add configuration test command (#524)

main.go

@@ -10,13 +10,16 @@ import (
 	"syscall"
 
 	"github.com/Dreamacro/clash/config"
+	"github.com/Dreamacro/clash/constant"
 	C "github.com/Dreamacro/clash/constant"
 	"github.com/Dreamacro/clash/hub"
+	"github.com/Dreamacro/clash/hub/executor"
 	"github.com/Dreamacro/clash/log"
 )
 
 var (
 	version    bool
+	testConfig bool
 	homeDir    string
 	configFile string
 )
@@ -25,6 +28,7 @@ func init() {
 	flag.StringVar(&homeDir, "d", "", "set configuration directory")
 	flag.StringVar(&configFile, "f", "", "specify configuration file")
 	flag.BoolVar(&version, "v", false, "show current version of clash")
+	flag.BoolVar(&testConfig, "t", false, "test configuration and exit")
 	flag.Parse()
 }
 
@@ -57,6 +61,16 @@ func main() {
 		log.Fatalln("Initial configuration directory error: %s", err.Error())
 	}
 
+	if testConfig {
+		if _, err := executor.Parse(); err != nil {
+			log.Errorln(err.Error())
+			fmt.Printf("configuration file %s test failed\n", constant.Path.Config())
+			os.Exit(1)
+		}
+		fmt.Printf("configuration file %s test is successful\n", constant.Path.Config())
+		return
+	}
+
 	if err := hub.Parse(); err != nil {
 		log.Fatalln("Parse config error: %s", err.Error())
 	}