fix websocket error catching

Author: zmh-program

Diff for: README.md

@@ -30,7 +30,10 @@ instance := chatnio.NewInstanceFromEnv("CHATNIO_TOKEN")
 
 - Chat
 ```go
-chat := instance.NewChat(-1) // id -1: creating new chat
+chat, err := instance.NewChat(-1) // id -1: creating new chat
+if err != nil {
+    panic(err)
+}
 
 // using hook
 chat.AskStream(&chatnio.ChatRequestForm{

Diff for: chat.go

@@ -27,13 +27,18 @@ type ChatPartialResponse struct {
 	End     bool    `json:"end"`
 }
 
-func (i *Instance) NewChat(id int) *Chat {
+func (i *Instance) NewChat(id int) (*Chat, error) {
+	conn, err := utils.NewWebsocket(i.GetChatEndpoint())
+	if err != nil {
+		return nil, err
+	}
+
 	return &Chat{
 		Id:    id,
 		Uri:   i.GetChatEndpoint(),
 		Token: i.GetApiKey(),
-		Conn:  utils.NewWebsocket(i.GetChatEndpoint()),
-	}
+		Conn:  conn,
+	}, nil
 }
 
 func (c *Chat) Send(v interface{}) bool {

Diff for: chat_test.go

@@ -11,7 +11,12 @@ func TestChat_AskStream(t *testing.T) {
 		return
 	}
 
-	chat := instance.NewChat(-1)
+	chat, err := instance.NewChat(-1)
+	if err != nil {
+		t.Errorf(fmt.Sprintf("error occurred: %s", err.Error()))
+		return
+	}
+
 	defer chat.DeferClose()
 
 	chat.AskStream(&ChatRequestForm{
@@ -27,9 +32,14 @@ func TestChat_Ask(t *testing.T) {
 		return
 	}
 
-	chat := instance.NewChat(-1)
+	chat, err := instance.NewChat(-1)
 	defer chat.DeferClose()
 
+	if err != nil {
+		t.Errorf(fmt.Sprintf("error occurred: %s", err.Error()))
+		return
+	}
+
 	channel := make(chan ChatPartialResponse)
 	chat.Ask(&ChatRequestForm{
 		Message: "hello",

Diff for: utils/websocket.go

@@ -10,15 +10,17 @@ type WebSocket struct {
 	Cursor int
 }
 
-func NewWebsocket(url string) *WebSocket {
-	if conn, _, err := websocket.DefaultDialer.Dial(url, nil); err != nil {
-		return nil
-	} else {
-		return &WebSocket{
-			Conn:   conn,
-			Cursor: 0,
-		}
+func NewWebsocket(url string) (ws *WebSocket, err error) {
+	conn, _, err := websocket.DefaultDialer.Dial(url, nil)
+	if err != nil {
+		return
+	}
+
+	ws = &WebSocket{
+		Conn:   conn,
+		Cursor: 0,
 	}
+	return
 }
 
 func (w *WebSocket) GetCursor() int {

Diff for: utils/websocket_test.go

@@ -1,12 +1,13 @@
 package utils
 
 import (
+	"fmt"
 	"testing"
 )
 
 func TestNewWebsocket(t *testing.T) {
-	ws := NewWebsocket("wss://api.chatnio.net/chat")
-	if ws == nil {
-		t.Error("websocket is nil")
+	_, err := NewWebsocket("wss://api.chatnio.net/chat")
+	if err != nil {
+		t.Errorf(fmt.Sprintf("error occurred: %s", err.Error()))
 	}
 }