Add test case for load settings

godns.go

@@ -2,7 +2,9 @@ package main
 
 import (
 	"flag"
+	"fmt"
 	"log"
+	"os"
 	"runtime/debug"
 	"strings"
 	"time"
@@ -32,7 +34,15 @@ func main() {
 		return
 	}
 
-	Configuration = LoadSettings(*optConf)
+	var err error
+	Configuration, err = LoadSettings(*optConf)
+
+	if err != nil {
+		fmt.Println(err.Error())
+		log.Println(err.Error())
+		os.Exit(1)
+	}
+
 	dns_loop()
 }
 

settings.go

@@ -4,7 +4,6 @@ import (
 	"encoding/json"
 	"fmt"
 	"io/ioutil"
-	"os"
 )
 
 type Settings struct {
@@ -21,19 +20,19 @@ type Settings struct {
 	Group      int
 }
 
-func LoadSettings(config_path string) Settings {
+func LoadSettings(config_path string) (Settings, error) {
+	setting := Settings{}
 	file, err := ioutil.ReadFile(config_path)
 	if err != nil {
 		fmt.Println("Error occurs while reading config file, please make sure config file exists!")
-		os.Exit(1)
+		return setting, err
 	}
 
-	var setting Settings
 	err = json.Unmarshal(file, &setting)
 	if err != nil {
 		fmt.Println("Error occurs while unmarshal config file, please make sure config file correct!")
-		os.Exit(1)
+		return setting, err
 	}
 
-	return setting
+	return setting, nil
 }

settings_test.go

@@ -0,0 +1,17 @@
+package main
+
+import (
+	"testing"
+)
+
+func TestLoadSetting(t *testing.T) {
+	settings, err := LoadSettings("./config_sample.json")
+
+	if err != nil {
+		t.Error(err.Error())
+	}
+
+	if settings.IP_Url == "" {
+		t.Error("Cannot load ip_url from config file")
+	}
+}