chore: update line-bot-sdk-go to v8.23.0 and refactor handler

.github/workflows/go.yml

@@ -11,12 +11,12 @@ jobs:
   build:
     runs-on: ubuntu-latest
     steps:
-    - uses: actions/checkout@v4
+    - uses: actions/checkout@v7
 
     - name: Set up Go
-      uses: actions/setup-go@v5
+      uses: actions/setup-go@v7
       with:
-        go-version: '1.25'
+        go-version-file: go.mod
 
     - name: Build
       run: go build -v ./...

README.md

@@ -13,14 +13,14 @@ A minimal Golang LINE Bot template built on the official [line-bot-sdk-go v8](ht
 - Replies with the sticker ID / resource type when it receives a sticker
 - Logs every incoming event so you can see the payload shape while developing
 
-That is the whole app — one file, [`main.go`](main.go), roughly 100 lines. It is meant to be read and then rewritten into your own bot.
+That is the whole app — one file, [`main.go`](main.go), roughly 150 lines. It is meant to be read and then rewritten into your own bot.
 
 ## Requirements
 
 | | |
 |---|---|
-| Go | 1.25 or later |
-| SDK | `github.com/line/line-bot-sdk-go/v8` v8.22.0 |
+| Go | 1.26 or later |
+| SDK | `github.com/line/line-bot-sdk-go/v8` v8.23.0 |
 
 ## Environment variables
 
@@ -93,10 +93,10 @@ Then set the webhook URL to `https://<subdomain>.ngrok-free.app/callback`.
 
 ## Making it your own
 
-All the interesting code lives in the event loop in `main.go`:
+All the interesting code lives in `handleEvent` in `main.go`; `callbackHandler` verifies the signature and feeds it each event, and `replyText` is a helper for plain text replies:
 
 ```go
-for _, event := range cb.Events {
+func handleEvent(bot *messaging_api.MessagingApiAPI, event webhook.EventInterface) {
     switch e := event.(type) {
     case webhook.MessageEvent:
         switch message := e.Message.(type) {

go.mod

@@ -1,6 +1,6 @@
 module github.com/kkdai/LineBotTemplate
 
-// +heroku goVersion go1.25
-go 1.25
+// +heroku goVersion go1.26
+go 1.26
 
-require github.com/line/line-bot-sdk-go/v8 v8.22.0
+require github.com/line/line-bot-sdk-go/v8 v8.23.0

go.sum

@@ -1,2 +1,2 @@
-github.com/line/line-bot-sdk-go/v8 v8.22.0 h1:jkxX5Ds8zlPSxUYil63P/Xg52SJ+kN/Xa7A4t/ItlDw=
-github.com/line/line-bot-sdk-go/v8 v8.22.0/go.mod h1:QMXJwPka2ysSeVQKWXkBp8DzBFs+CFAXFNo75KJtWho=
+github.com/line/line-bot-sdk-go/v8 v8.23.0 h1:Yw+6RjCmVvZdKX+0H/ZeWIoTqYFFk8WojGB5qYuAafo=
+github.com/line/line-bot-sdk-go/v8 v8.23.0/go.mod h1:WCVmO0tLqNcNZMu3Vldsg6CgXikjVOkzgZzWDENJ+Zo=

main.go

@@ -24,94 +24,81 @@ import (
 )
 
 func main() {
-	channelSecret := os.Getenv("ChannelSecret")
-	bot, err := messaging_api.NewMessagingApiAPI(
-		os.Getenv("ChannelAccessToken"),
-	)
+	bot, err := messaging_api.NewMessagingApiAPI(os.Getenv("ChannelAccessToken"))
 	if err != nil {
 		log.Fatal(err)
 	}
 
 	// Setup HTTP Server for receiving requests from LINE platform
-	http.HandleFunc("/callback", func(w http.ResponseWriter, req *http.Request) {
-		log.Println("/callback called...")
+	http.HandleFunc("/callback", callbackHandler(os.Getenv("ChannelSecret"), bot))
 
+	// This is just sample code.
+	// For actual use, you must support HTTPS by using `ListenAndServeTLS`, a reverse proxy or something else.
+	port := os.Getenv("PORT")
+	if port == "" {
+		port = "5000"
+	}
+	fmt.Println("http://localhost:" + port + "/")
+	if err := http.ListenAndServe(":"+port, nil); err != nil {
+		log.Fatal(err)
+	}
+}
+
+// callbackHandler returns the webhook handler: it verifies the LINE signature,
+// then dispatches every event in the request.
+func callbackHandler(channelSecret string, bot *messaging_api.MessagingApiAPI) http.HandlerFunc {
+	return func(w http.ResponseWriter, req *http.Request) {
 		cb, err := webhook.ParseRequest(channelSecret, req)
 		if err != nil {
 			log.Printf("Cannot parse request: %+v\n", err)
 			if errors.Is(err, webhook.ErrInvalidSignature) {
-				w.WriteHeader(400)
+				w.WriteHeader(http.StatusBadRequest)
 			} else {
-				w.WriteHeader(500)
+				w.WriteHeader(http.StatusInternalServerError)
 			}
 			return
 		}
 
-		log.Println("Handling events...")
 		for _, event := range cb.Events {
-			log.Printf("/callback called%+v...\n", event)
-
-			switch e := event.(type) {
-			case webhook.MessageEvent:
-				switch message := e.Message.(type) {
-				case webhook.TextMessageContent:
-					if _, err = bot.ReplyMessage(
-						&messaging_api.ReplyMessageRequest{
-							ReplyToken: e.ReplyToken,
-							Messages: []messaging_api.MessageInterface{
-								messaging_api.TextMessage{
-									Text: message.Text,
-								},
-							},
-						},
-					); err != nil {
-						log.Print(err)
-					} else {
-						log.Println("Sent text reply.")
-					}
-				case webhook.StickerMessageContent:
-					replyMessage := fmt.Sprintf(
-						"貼圖訊息: sticker id is %s, stickerResourceType is %s", message.StickerId, message.StickerResourceType)
-					if _, err = bot.ReplyMessage(
-						&messaging_api.ReplyMessageRequest{
-							ReplyToken: e.ReplyToken,
-							Messages: []messaging_api.MessageInterface{
-								messaging_api.TextMessage{
-									Text: replyMessage,
-								},
-							},
-						}); err != nil {
-						log.Print(err)
-					} else {
-						log.Println("Sent sticker reply.")
-					}
-				default:
-					log.Printf("Unsupported message content: %T\n", e.Message)
-				}
-			case webhook.FollowEvent:
-				log.Printf("Followed by %s\n", sourceID(e.Source))
-			case webhook.MemberJoinedEvent:
-				log.Printf("Members joined %s: %s\n", sourceID(e.Source), userIDs(orZero(e.Joined).Members))
-			case webhook.MemberLeftEvent:
-				log.Printf("Members left %s: %s\n", sourceID(e.Source), userIDs(orZero(e.Left).Members))
-			case webhook.BeaconEvent:
-				beacon := orZero(e.Beacon)
-				log.Printf("Beacon %q from %s: hwid=%s\n", beacon.Type, sourceID(e.Source), beacon.Hwid)
-			default:
-				log.Printf("Unsupported event: %T\n", event)
-			}
+			log.Printf("Handling event: %+v\n", event)
+			handleEvent(bot, event)
 		}
-	})
+	}
+}
 
-	// This is just sample code.
-	// For actual use, you must support HTTPS by using `ListenAndServeTLS`, a reverse proxy or something else.
-	port := os.Getenv("PORT")
-	if port == "" {
-		port = "5000"
+func handleEvent(bot *messaging_api.MessagingApiAPI, event webhook.EventInterface) {
+	switch e := event.(type) {
+	case webhook.MessageEvent:
+		switch message := e.Message.(type) {
+		case webhook.TextMessageContent:
+			replyText(bot, e.ReplyToken, message.Text)
+		case webhook.StickerMessageContent:
+			replyText(bot, e.ReplyToken, fmt.Sprintf(
+				"貼圖訊息: sticker id is %s, stickerResourceType is %s", message.StickerId, message.StickerResourceType))
+		default:
+			log.Printf("Unsupported message content: %T\n", e.Message)
+		}
+	case webhook.FollowEvent:
+		log.Printf("Followed by %s\n", sourceID(e.Source))
+	case webhook.MemberJoinedEvent:
+		log.Printf("Members joined %s: %s\n", sourceID(e.Source), userIDs(orZero(e.Joined).Members))
+	case webhook.MemberLeftEvent:
+		log.Printf("Members left %s: %s\n", sourceID(e.Source), userIDs(orZero(e.Left).Members))
+	case webhook.BeaconEvent:
+		beacon := orZero(e.Beacon)
+		log.Printf("Beacon %q from %s: hwid=%s\n", beacon.Type, sourceID(e.Source), beacon.Hwid)
+	default:
+		log.Printf("Unsupported event: %T\n", event)
 	}
-	fmt.Println("http://localhost:" + port + "/")
-	if err := http.ListenAndServe(":"+port, nil); err != nil {
-		log.Fatal(err)
+}
+
+// replyText answers a reply token with a single text message.
+func replyText(bot *messaging_api.MessagingApiAPI, replyToken, text string) {
+	if _, err := bot.ReplyMessage(&messaging_api.ReplyMessageRequest{
+		ReplyToken: replyToken,
+		Messages:   []messaging_api.MessageInterface{messaging_api.TextMessage{Text: text}},
+	}); err != nil {
+		log.Print(err)
 	}
 }