kucoin: refactor bullet url code

examples/kucoin/websocket.go

@@ -3,7 +3,6 @@ package main
 import (
 	"context"
 	"errors"
-	"net/url"
 	"os"
 	"os/signal"
 	"time"
@@ -59,7 +58,7 @@ var websocketCmd = &cobra.Command{
 		}
 
 
-		u, err := url.Parse(bullet.InstanceServers[0].Endpoint)
+		u, err := bullet.URL()
 		if err != nil {
 			return err
 		}
@@ -67,12 +66,7 @@ var websocketCmd = &cobra.Command{
 		interrupt := make(chan os.Signal, 1)
 		signal.Notify(interrupt, os.Interrupt)
 
-		params := url.Values{}
-		params.Add("token", bullet.Token)
-		u.RawQuery = params.Encode()
-
 		logrus.Infof("connecting %s", u.String())
-
 		c, _, err := websocket.DefaultDialer.Dial(u.String(), nil)
 		if err != nil {
 			return err

pkg/exchange/kucoin/kucoinapi/bullet.go

@@ -6,6 +6,7 @@ import (
 	"net/url"
 
 	"github.com/c9s/bbgo/pkg/util"
+	"github.com/pkg/errors"
 )
 
 // ApiClient defines the request builder method and request method for the API service
@@ -48,6 +49,23 @@ type Bullet struct {
 	Token string `json:"token"`
 }
 
+func (b *Bullet) URL() (*url.URL, error) {
+	if len(b.InstanceServers) == 0 {
+		return nil, errors.New("InstanceServers is empty")
+	}
+
+	u, err := url.Parse(b.InstanceServers[0].Endpoint)
+	if err != nil {
+		return nil, err
+	}
+
+	params := url.Values{}
+	params.Add("token", b.Token)
+
+	u.RawQuery = params.Encode()
+	return u, nil
+}
+
 func (r *GetPublicBulletRequest) Do(ctx context.Context) (*Bullet, error) {
 	req, err := r.client.NewRequest("POST", "/api/v1/bullet-public", nil, nil)
 	if err != nil {