Merge pull request #25 from Neur0toxine/send-reactions

add reaction sending support for Instagram

.github/workflows/ci.yml

@@ -19,17 +19,24 @@ jobs:
     steps:
       - name: Check out code into the Go module directory
         uses: actions/checkout@v2
-      - name: Lint code with golangci-lint
-        uses: golangci/golangci-lint-action@v2
+      - name: Set up Go 1.17
+        uses: actions/setup-go@v2
         with:
-          version: v1.36
+          # TODO: Should migrate to 1.18 later
+          go-version: '1.17'
+      - name: Get dependencies
+        run: go mod tidy
+      - name: Lint code with golangci-lint
+        uses: golangci/golangci-lint-action@v3
+        with:
+          version: v1.50.1
           only-new-issues: true
   tests:
     name: Tests
     runs-on: ubuntu-latest
     strategy:
       matrix:
-        go-version: ['1.11', '1.12', '1.13', '1.14', '1.15']
+        go-version: ['1.13', '1.14', '1.15', '1.16', '1.17']
     steps:
       - name: Set up Go ${{ matrix.go-version }}
         uses: actions/setup-go@v2

.golangci.yml

@@ -6,20 +6,33 @@ output:
   format: colored-line-number
   sort-results: true
 
+# Linters below do not support go1.18 yet because of generics.
+# See https://github.com/golangci/golangci-lint/issues/2649
+#    - bodyclose
+#    - sqlclosecheck
+
 linters:
   disable-all: true
   enable:
-    - deadcode
+    - paralleltest
+    - tparallel
+    - asciicheck
+    - asasalint
+    - varnamelen
+    - reassign
+    - nilnil
+    - nilerr
+    - nakedret
+    - goprintffuncname
+    - typecheck
+    - errchkjson
     - errcheck
     - gosimple
     - govet
     - ineffassign
     - staticcheck
-    - structcheck
     - unused
     - unparam
-    - varcheck
-    - bodyclose
     - dogsled
     - dupl
     - errorlint
@@ -32,20 +45,15 @@ linters:
     - gocyclo
     - godot
     - goimports
-    - golint
-    - gomnd
+    - revive
     - gosec
-    - ifshort
-    - interfacer
     - lll
     - makezero
-    - maligned
     - misspell
     - nestif
     - prealloc
     - predeclared
-    - scopelint
-    - sqlclosecheck
+    - exportloopref
     - unconvert
     - whitespace
 
@@ -56,9 +64,11 @@ linters-settings:
     enable:
       - assign
       - atomic
+      - atomicalign
       - bools
       - buildtag
       - copylocks
+      - fieldalignment
       - httpresponse
       - loopclosure
       - lostcancel
@@ -70,7 +80,6 @@ linters-settings:
       - unmarshal
       - unreachable
       - unsafeptr
-      - unused
     settings:
       printf:
         funcs:
@@ -129,11 +138,13 @@ linters-settings:
     threshold: 200
   errorlint:
     errorf: true
+    asserts: false
+    comparison: false
   exhaustive:
     check-generated: false
     default-signifies-exhaustive: false
   funlen:
-    lines: 60
+    lines: 90
     statements: 40
   gocognit:
     min-complexity: 25
@@ -143,8 +154,6 @@ linters-settings:
     local-prefixes: github.com/retailcrm/messenger
   lll:
     line-length: 120
-  maligned:
-    suggest-new: true
   misspell:
     locale: US
   nestif:
@@ -152,28 +161,36 @@ linters-settings:
   whitespace:
     multi-if: false
     multi-func: false
-
+  varnamelen:
+    max-distance: 10
+    ignore-map-index-ok: true
+    ignore-type-assert-ok: true
+    ignore-chan-recv-ok: true
+    ignore-decls:
+      - t *testing.T
+      - e error
+      - i int
 issues:
   exclude-rules:
     - path: _test\.go
       linters:
-        - gomnd
         - lll
-        - bodyclose
         - errcheck
-        - sqlclosecheck
         - misspell
         - ineffassign
         - whitespace
         - makezero
-        - maligned
-        - ifshort
         - errcheck
         - funlen
         - goconst
         - gocognit
         - gocyclo
         - godot
+        - unused
+        - errchkjson
+        - varnamelen
+    - path: \.go
+      text: "Error return value of `io.WriteString` is not checked"
   exclude-use-default: true
   exclude-case-sensitive: false
   max-issues-per-linter: 0
@@ -185,4 +202,4 @@ severity:
   case-sensitive: false
 
 service:
-  golangci-lint-version: 1.36.x
+  golangci-lint-version: 1.50.x

actions.go

@@ -24,3 +24,20 @@ const (
 	// status.
 	AccountLinkingAction
 )
+
+// SenderAction is used to send a specific action (event) to the Facebook.
+// The result of sending said action is supposed to give more interactivity to the bot.
+type SenderAction string
+
+const (
+	// MarkSeen marks message as seen.
+	MarkSeen SenderAction = "MARK_SEEN"
+	// TypingOn turns on "Bot is typing..." indicator.
+	TypingOn SenderAction = "TYPING_ON"
+	// TypingOff turns off typing indicator.
+	TypingOff SenderAction = "TYPING_OFF"
+	// React to the message.
+	React SenderAction = "REACT"
+	// Unreact to the message (remove reaction).
+	Unreact SenderAction = "UNREACT"
+)

go.mod

@@ -1,8 +1,11 @@
 module github.com/retailcrm/messenger
 
+require (
+	github.com/stretchr/testify v1.2.2
+	golang.org/x/xerrors v0.0.0-20190717185122-a985d3407aa7
+)
+
 require (
 	github.com/davecgh/go-spew v1.1.1 // indirect
 	github.com/pmezard/go-difflib v1.0.0 // indirect
-	github.com/stretchr/testify v1.2.2
-	golang.org/x/xerrors v0.0.0-20190717185122-a985d3407aa7
 )

message.go

@@ -33,6 +33,18 @@ type Message struct {
 	// Entities for NLP
 	// https://developers.facebook.com/docs/messenger-platform/built-in-nlp/
 	NLP json.RawMessage `json:"nlp"`
+	// Read Instagram message data to which this reply was sent to.
+	Read *IGMessageRead `json:"read,omitempty"`
+	// Reaction represents reaction to Instagram message.
+	Reaction *IGMessageReaction `json:"reaction,omitempty"`
+	// Referral with Instagram product data.
+	Referral *IGMessageReferral `json:"referral,omitempty"`
+	// IsUnsupported is being sent if Instagram message is not supported.
+	IsUnsupported bool `json:"is_unsupported,omitempty"`
+	// IsDeleted is being sent if message was deleted.
+	IsDeleted bool `json:"is_deleted,omitempty"`
+	// ReplyTo the Instagram story or to the message.
+	ReplyTo *IGReplyTo `json:"reply_to"`
 }
 
 // Delivery represents a the event fired when Facebook delivers a message to the
@@ -54,6 +66,64 @@ type Read struct {
 	RawWatermark int64 `json:"watermark"`
 	// Seq is the sequence the message was sent in.
 	Seq int `json:"seq"`
+	// Mid is the ID of the message.
+	Mid string `json:"mid"`
+}
+
+// IGMessageRead represents data with the read message ID. Present in the Instagram webhook.
+type IGMessageRead struct {
+	// Mid is a message ID.
+	Mid string `json:"mid"`
+}
+
+// IGMessageReaction represents reaction to the Instagram message.
+type IGMessageReaction struct {
+	// Mid is a message ID.
+	Mid string `json:"mid"`
+	// Action can be {react|unreact}
+	Action ReactionAction `json:"action"`
+	// Reaction is a reaction name. Optional.
+	Reaction string `json:"reaction,omitempty"`
+	// Emoji is optional.
+	Emoji string `json:"emoji,omitempty"`
+}
+
+// IGMessageProduct represents Instagram product.
+type IGMessageProduct struct {
+	// ID of the product.
+	ID string `json:"id,omitempty"`
+}
+
+// IGMessageReferral represents Instagram message referral with ad data and product ID.
+type IGMessageReferral struct {
+	// Ad data
+	Referral
+	// Product data.
+	Product IGMessageProduct `json:"product,omitempty"`
+}
+
+// IGPostback represents Instagram postback webhook data.
+type IGPostback struct {
+	// Selected icebreaker question or title for the CTA (Generic Template)
+	Title string `json:"title,omitempty"`
+	// Payload is user defined payload.
+	Payload string `json:"payload"`
+}
+
+// IGReplyTo represents data of the thing to what reply has been sent.
+type IGReplyTo struct {
+	// Mid is a message ID to which reply was sent.
+	Mid string `json:"mid"`
+	// Story data.
+	Story *IGReplyToStory `json:"story,omitempty"`
+}
+
+// IGReplyToStory is a story data to which reply has been sent.
+type IGReplyToStory struct {
+	// URL of the story.
+	URL string `json:"url,omitempty"`
+	// ID of the story.
+	ID string `json:"id,omitempty"`
 }
 
 // PostBack represents postback callback.
@@ -68,6 +138,10 @@ type PostBack struct {
 	Payload string `json:"payload"`
 	// Optional referral info
 	Referral Referral `json:"referral"`
+	// Title for the CTA that was clicked on
+	Title string `json:"title"`
+	// Message ID
+	Mid string `json:"mid"`
 }
 
 type AccountLinking struct {

messenger.go

@@ -48,6 +48,8 @@ type Options struct {
 	WebhookURL string
 	// Mux is shared mux between several Messenger objects
 	Mux *http.ServeMux
+	// SendAPIVersion is a Send API version
+	SendAPIVersion string
 }
 
 // MessageHandler is a handler used for responding to a message containing text.
@@ -86,6 +88,7 @@ type Messenger struct {
 	verifyHandler          func(http.ResponseWriter, *http.Request)
 	verify                 bool
 	appSecret              string
+	sendAPIVersion         string
 }
 
 // New creates a new Messenger. You pass in Options in order to affect settings.
@@ -95,16 +98,21 @@ func New(mo Options) *Messenger {
 	}
 
 	m := &Messenger{
-		mux:       mo.Mux,
-		token:     mo.Token,
-		verify:    mo.Verify,
-		appSecret: mo.AppSecret,
+		mux:            mo.Mux,
+		token:          mo.Token,
+		verify:         mo.Verify,
+		appSecret:      mo.AppSecret,
+		sendAPIVersion: mo.SendAPIVersion,
 	}
 
 	if mo.WebhookURL == "" {
 		mo.WebhookURL = "/"
 	}
 
+	if m.sendAPIVersion == "" {
+		m.sendAPIVersion = DefaultSendAPIVersion
+	}
+
 	m.verifyHandler = newVerifyHandler(mo.VerifyToken)
 	m.mux.HandleFunc(mo.WebhookURL, m.handle)
 
@@ -190,7 +198,7 @@ func (m *Messenger) ProfileByID(id int64, profileFields []string) (Profile, erro
 
 	err = json.Unmarshal(content, &p)
 	if err != nil {
-		return p, err
+		return p, NewUnmarshalError(err).WithContent(content)
 	}
 
 	if p == *new(Profile) {
@@ -366,8 +374,9 @@ func (m *Messenger) dispatch(r Receive) {
 			}
 
 			resp := &Response{
-				to:    Recipient{info.Sender.ID},
-				token: m.token,
+				to:             Recipient{ID: info.Sender.ID},
+				token:          m.token,
+				sendAPIVersion: m.sendAPIVersion,
 			}
 
 			switch a {
@@ -427,8 +436,9 @@ func (m *Messenger) dispatch(r Receive) {
 // Response returns new Response object.
 func (m *Messenger) Response(to int64) *Response {
 	return &Response{
-		to:    Recipient{to},
-		token: m.token,
+		to:             Recipient{ID: to},
+		token:          m.token,
+		sendAPIVersion: m.sendAPIVersion,
 	}
 }
 
@@ -440,8 +450,9 @@ func (m *Messenger) Send(to Recipient, message string, messagingType MessagingTy
 // SendGeneralMessage will send the GenericTemplate message.
 func (m *Messenger) SendGeneralMessage(to Recipient, elements *[]StructuredMessageElement, messagingType MessagingType, metadata string, tags ...string) (QueryResponse, error) {
 	r := &Response{
-		token: m.token,
-		to:    to,
+		token:          m.token,
+		to:             to,
+		sendAPIVersion: m.sendAPIVersion,
 	}
 	return r.GenericTemplate(elements, messagingType, metadata, tags...)
 }
@@ -449,8 +460,9 @@ func (m *Messenger) SendGeneralMessage(to Recipient, elements *[]StructuredMessa
 // SendWithReplies sends a textual message to a user, but gives them the option of numerous quick response options.
 func (m *Messenger) SendWithReplies(to Recipient, message string, replies []QuickReply, messagingType MessagingType, metadata string, tags ...string) (QueryResponse, error) {
 	response := &Response{
-		token: m.token,
-		to:    to,
+		token:          m.token,
+		to:             to,
+		sendAPIVersion: m.sendAPIVersion,
 	}
 
 	return response.TextWithReplies(message, replies, messagingType, metadata, tags...)
@@ -459,8 +471,9 @@ func (m *Messenger) SendWithReplies(to Recipient, message string, replies []Quic
 // Attachment sends an image, sound, video or a regular file to a given recipient.
 func (m *Messenger) Attachment(to Recipient, dataType AttachmentType, url string, messagingType MessagingType, metadata string, tags ...string) (QueryResponse, error) {
 	response := &Response{
-		token: m.token,
-		to:    to,
+		token:          m.token,
+		to:             to,
+		sendAPIVersion: m.sendAPIVersion,
 	}
 
 	return response.Attachment(dataType, url, messagingType, metadata, tags...)
@@ -495,6 +508,29 @@ func (m *Messenger) EnableChatExtension(homeURL HomeURL) error {
 	return checkFacebookError(resp.Body)
 }
 
+func (m *Messenger) SenderAction(to Recipient, action SenderAction) (QueryResponse, error) {
+	response := &Response{
+		token:          m.token,
+		to:             to,
+		sendAPIVersion: m.sendAPIVersion,
+	}
+	return response.SenderAction(action)
+}
+
+func (m *Messenger) InstagramReaction(
+	to Recipient,
+	mid string,
+	action ReactionAction,
+	reaction ...string,
+) (QueryResponse, error) {
+	response := &Response{
+		token:          m.token,
+		to:             to,
+		sendAPIVersion: m.sendAPIVersion,
+	}
+	return response.InstagramReaction(mid, action, reaction...)
+}
+
 // classify determines what type of message a webhook event is.
 func (m *Messenger) classify(info MessageInfo) Action {
 	if info.Message != nil {

messenger_test.go

@@ -106,7 +106,7 @@ func TestMessenger_Dispatch(t *testing.T) {
 		messages := []MessageInfo{
 			{
 				Sender:    Sender{111},
-				Recipient: Recipient{222},
+				Recipient: Recipient{ID: 222},
 				// 2018-11-24 21:31:51 UTC + 999ms
 				Timestamp: 1543095111999,
 				Message:   &Message{},
@@ -138,7 +138,7 @@ func TestMessenger_Dispatch(t *testing.T) {
 		messages := []MessageInfo{
 			{
 				Sender:    Sender{111},
-				Recipient: Recipient{222},
+				Recipient: Recipient{ID: 222},
 				// 2018-11-24 21:31:51 UTC + 999ms
 				Timestamp: 1543095111999,
 				Delivery:  &Delivery{},
@@ -170,7 +170,7 @@ func TestMessenger_Dispatch(t *testing.T) {
 		messages := []MessageInfo{
 			{
 				Sender:    Sender{111},
-				Recipient: Recipient{222},
+				Recipient: Recipient{ID: 222},
 				// 2018-11-24 21:31:51 UTC + 999ms
 				Timestamp: 1543095111999,
 				Read:      &Read{},
@@ -205,7 +205,7 @@ func TestMessenger_Dispatch(t *testing.T) {
 		messages := []MessageInfo{
 			{
 				Sender:    Sender{111},
-				Recipient: Recipient{222},
+				Recipient: Recipient{ID: 222},
 				// 2018-11-24 21:31:51 UTC + 999ms
 				Timestamp: 1543095111999,
 				PostBack:  &PostBack{},
@@ -240,7 +240,7 @@ func TestMessenger_Dispatch(t *testing.T) {
 		messages := []MessageInfo{
 			{
 				Sender:    Sender{111},
-				Recipient: Recipient{222},
+				Recipient: Recipient{ID: 222},
 				// 2018-11-24 21:31:51 UTC + 999ms
 				Timestamp: 1543095111999,
 				OptIn:     &OptIn{},
@@ -275,7 +275,7 @@ func TestMessenger_Dispatch(t *testing.T) {
 		messages := []MessageInfo{
 			{
 				Sender:    Sender{111},
-				Recipient: Recipient{222},
+				Recipient: Recipient{ID: 222},
 				// 2018-11-24 21:31:51 UTC + 999ms
 				Timestamp:       1543095111999,
 				ReferralMessage: &ReferralMessage{},

receiving.go

@@ -35,6 +35,8 @@ type MessageInfo struct {
 	// Delivery is the contents of a message if it is a DeliveryAction.
 	// Nil if it is not a DeliveryAction.
 	Delivery *Delivery `json:"delivery"`
+	// Reaction represents reaction to Instagram message.
+	Reaction *IGMessageReaction `json:"reaction,omitempty"`
 
 	PostBack *PostBack `json:"postback"`
 
@@ -78,6 +80,26 @@ type Referral struct {
 	Source string `json:"source"`
 	// The identifier dor the referral
 	Type string `json:"type"`
+	// ID of the ad
+	AdID string `json:"ad_id,omitempty"`
+	// The data containing information about the CTM ad, the user initiated the thread from.
+	AdsContextData AdsContextData `json:"ads_context_data,omitempty"`
+	// URI of the site from which the message was sent to the Facebook chat plugin.
+	RefererURI string `json:"referer_uri,omitempty"`
+}
+
+// AdsContextData represents data containing information about the CTM ad, the user initiated the thread from.
+type AdsContextData struct {
+	// Title of the Ad
+	AdTitle string `json:"ad_title"`
+	// Url of the image from the Ad the user is interested
+	PhotoURL string `json:"photo_url,omitempty"`
+	// Thumbnail url of the video from the ad
+	VideoURL string `json:"video_url,omitempty"`
+	// ID of the post
+	PostID string `json:"post_id"`
+	// Product ID from the Ad the user is interested
+	ProductID string `json:"product_id,omitempty"`
 }
 
 // Sender is who the message was sent from.
@@ -87,7 +109,9 @@ type Sender struct {
 
 // Recipient is who the message was sent to.
 type Recipient struct {
-	ID int64 `json:"id,string"`
+	ID        int64  `json:"id,string,omitempty"`
+	PostID    string `json:"post_id,omitempty"`
+	CommentID string `json:"comment_id,omitempty"`
 }
 
 // Attachment is a file which used in a message.
@@ -115,7 +139,20 @@ type Payload struct {
 	URL   string `json:"url,omitempty"`
 	Title string `json:"title,omitempty"`
 	// Coordinates is Lat/Long pair of location pin
-	Coordinates *Coordinates `json:"coordinates,omitempty"`
+	Coordinates  *Coordinates `json:"coordinates,omitempty"`
+	TemplateType string       `json:"template_type,omitempty"`
+	Buttons      []Button     `json:"buttons,omitempty"`
+}
+
+type Button struct {
+	Type                string `json:"type,omitempty"`
+	Title               string `json:"title,omitempty"`
+	Payload             string `json:"payload,omitempty"`
+	URL                 string `json:"url,omitempty"`
+	WebviewHeightRatio  string `json:"webview_height_ratio,omitempty"`
+	MessengerExtensions bool   `json:"messenger_extensions,omitempty"`
+	FallbackURL         string `json:"fallback_url,omitempty"`
+	WebviewShareButton  string `json:"webview_share_button,omitempty"`
 }
 
 // Coordinates is a pair of latitude and longitude.

response.go

@@ -23,10 +23,12 @@ type TopElementStyle string
 type ImageAspectRatio string
 
 const (
+	// DefaultSendAPIVersion is a default Send API version
+	DefaultSendAPIVersion = "v2.11"
 	// SendMessageURL is API endpoint for sending messages.
-	SendMessageURL = "https://graph.facebook.com/v2.11/me/messages"
+	SendMessageURL = "https://graph.facebook.com/%s/me/messages"
 	// ThreadControlURL is the API endpoint for passing thread control.
-	ThreadControlURL = "https://graph.facebook.com/v2.6/me/pass_thread_control"
+	ThreadControlURL = "https://graph.facebook.com/%s/me/pass_thread_control"
 	// InboxPageID is managed by facebook for secondary pass to inbox features: https://developers.facebook.com/docs/messenger-platform/handover-protocol/pass-thread-control
 	InboxPageID = 263902037430900
 
@@ -85,9 +87,10 @@ func checkFacebookError(r io.Reader) error {
 	var err error
 
 	qr := QueryResponse{}
-	err = json.NewDecoder(r).Decode(&qr)
+	decoder := json.NewDecoder(r)
+	err = decoder.Decode(&qr)
 	if err != nil {
-		return xerrors.Errorf("json unmarshal error: %w", err)
+		return NewUnmarshalError(err).WithReader(decoder.Buffered())
 	}
 	if qr.Error != nil {
 		return xerrors.Errorf("facebook error: %w", qr.Error)
@@ -98,9 +101,9 @@ func checkFacebookError(r io.Reader) error {
 
 func getFacebookQueryResponse(r io.Reader) (QueryResponse, error) {
 	qr := QueryResponse{}
-	err := json.NewDecoder(r).Decode(&qr)
-	if err != nil {
-		return qr, xerrors.Errorf("json unmarshal error: %w", err)
+	decoder := json.NewDecoder(r)
+	if err := decoder.Decode(&qr); err != nil {
+		return qr, NewUnmarshalError(err).WithReader(decoder.Buffered())
 	}
 	if qr.Error != nil {
 		return qr, xerrors.Errorf("facebook error: %w", qr.Error)
@@ -110,8 +113,9 @@ func getFacebookQueryResponse(r io.Reader) (QueryResponse, error) {
 
 // Response is used for responding to events with messages.
 type Response struct {
-	token string
-	to    Recipient
+	token          string
+	to             Recipient
+	sendAPIVersion string
 }
 
 // SetToken is for using DispatchMessage from outside.
@@ -178,7 +182,7 @@ func (r *Response) Image(im image.Image) (QueryResponse, error) {
 		return qr, err
 	}
 
-	return r.AttachmentData(ImageAttachment, "meme.jpg", imageBytes)
+	return r.AttachmentData(ImageAttachment, "meme.jpg", "image/jpeg", imageBytes)
 }
 
 // Attachment sends an image, sound, video or a regular file to a chat.
@@ -224,15 +228,14 @@ func createFormFile(filename string, w *multipart.Writer, contentType string) (i
 }
 
 // AttachmentData sends an image, sound, video or a regular file to a chat via an io.Reader.
-func (r *Response) AttachmentData(dataType AttachmentType, filename string, filedata io.Reader) (QueryResponse, error) {
+func (r *Response) AttachmentData(
+	dataType AttachmentType, filename string, contentType string, filedata io.Reader) (QueryResponse, error) {
 	var qr QueryResponse
 
 	filedataBytes, err := ioutil.ReadAll(filedata)
 	if err != nil {
 		return qr, err
 	}
-	contentType := http.DetectContentType(filedataBytes[:512])
-	fmt.Println("Content-type detected:", contentType)
 
 	var body bytes.Buffer
 	multipartWriter := multipart.NewWriter(&body)
@@ -249,7 +252,7 @@ func (r *Response) AttachmentData(dataType AttachmentType, filename string, file
 	multipartWriter.WriteField("recipient", fmt.Sprintf(`{"id":"%v"}`, r.to.ID))
 	multipartWriter.WriteField("message", fmt.Sprintf(`{"attachment":{"type":"%v", "payload":{}}}`, dataType))
 
-	req, err := http.NewRequest("POST", SendMessageURL, &body)
+	req, err := http.NewRequest("POST", fmt.Sprintf(SendMessageURL, r.sendAPIVersion), &body)
 	if err != nil {
 		return qr, err
 	}
@@ -348,8 +351,8 @@ func (r *Response) ListTemplate(elements *[]StructuredMessageElement, messagingT
 	return r.DispatchMessage(&m)
 }
 
-// SenderAction sends a info about sender action.
-func (r *Response) SenderAction(action string) (QueryResponse, error) {
+// SenderAction sends an info about sender action.
+func (r *Response) SenderAction(action SenderAction) (QueryResponse, error) {
 	m := SendSenderAction{
 		Recipient:    r.to,
 		SenderAction: action,
@@ -357,6 +360,21 @@ func (r *Response) SenderAction(action string) (QueryResponse, error) {
 	return r.DispatchMessage(&m)
 }
 
+// InstagramReaction sends an info about Instagram reaction.
+func (r *Response) InstagramReaction(mid string, action ReactionAction, reaction ...string) (QueryResponse, error) {
+	m := SendInstagramReaction{
+		Recipient:    r.to,
+		SenderAction: action,
+		Payload: SenderInstagramReactionPayload{
+			MessageID: mid,
+		},
+	}
+	if len(reaction) > 0 {
+		m.Payload.Reaction = reaction[0]
+	}
+	return r.DispatchMessage(&m)
+}
+
 // DispatchMessage posts the message to messenger, return the error if there's any.
 func (r *Response) DispatchMessage(m interface{}) (QueryResponse, error) {
 	var res QueryResponse
@@ -365,7 +383,7 @@ func (r *Response) DispatchMessage(m interface{}) (QueryResponse, error) {
 		return res, err
 	}
 
-	req, err := http.NewRequest("POST", SendMessageURL, bytes.NewBuffer(data))
+	req, err := http.NewRequest("POST", fmt.Sprintf(SendMessageURL, r.sendAPIVersion), bytes.NewBuffer(data))
 	if err != nil {
 		return res, err
 	}
@@ -397,7 +415,7 @@ func (r *Response) PassThreadToInbox() error {
 		return err
 	}
 
-	req, err := http.NewRequest("POST", ThreadControlURL, bytes.NewBuffer(data))
+	req, err := http.NewRequest("POST", fmt.Sprintf(ThreadControlURL, r.sendAPIVersion), bytes.NewBuffer(data))
 	if err != nil {
 		return err
 	}
@@ -508,7 +526,7 @@ type StructuredMessageElement struct {
 	ItemURL       string                     `json:"item_url,omitempty"`
 	Subtitle      string                     `json:"subtitle"`
 	DefaultAction *DefaultAction             `json:"default_action,omitempty"`
-	Buttons       *[]StructuredMessageButton `json:"buttons"`
+	Buttons       *[]StructuredMessageButton `json:"buttons,omitempty"`
 	ReceiptMessageElement
 }
 
@@ -543,6 +561,29 @@ type StructuredMessageButton struct {
 
 // SendSenderAction is the information about sender action.
 type SendSenderAction struct {
-	Recipient    Recipient `json:"recipient"`
-	SenderAction string    `json:"sender_action"`
+	Recipient    Recipient    `json:"recipient"`
+	SenderAction SenderAction `json:"sender_action"`
+}
+
+// ReactionAction contains info about reaction action type.
+type ReactionAction string
+
+const (
+	// ReactionActionReact is used when user added a reaction.
+	ReactionActionReact ReactionAction = "react"
+	// ReactionActionUnReact is used when user removed a reaction.
+	ReactionActionUnReact ReactionAction = "unreact"
+)
+
+// SendInstagramReaction is the information about sender action.
+type SendInstagramReaction struct {
+	Recipient    Recipient                      `json:"recipient"`
+	SenderAction ReactionAction                 `json:"sender_action"`
+	Payload      SenderInstagramReactionPayload `json:"payload"`
+}
+
+// SenderInstagramReactionPayload contains target message ID and reaction name.
+type SenderInstagramReactionPayload struct {
+	MessageID string `json:"message_id"`
+	Reaction  string `json:"reaction"`
 }

response_test.go

@@ -0,0 +1,33 @@
+package messenger
+
+import (
+	"bytes"
+	"encoding/json"
+	"errors"
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+)
+
+func Test_MarshalStructuredMessageElement(t *testing.T) {
+	data, err := json.Marshal(StructuredMessageElement{
+		Title: "Title",
+	})
+	require.NoError(t, err)
+	assert.JSONEq(t, string(data), `{"image_url":"", "subtitle":"", "title": "Title"}`)
+}
+
+func TestResponse_checkFacebookError_UnmarshalError(t *testing.T) {
+	r := bytes.NewReader([]byte("test error text"))
+	err := checkFacebookError(r)
+	assert.True(t, errors.Is(err, ErrUnmarshal))
+	assert.Contains(t, err.Error(), "test error text")
+}
+
+func TestResponse_getFacebookQueryResponse_UnmarshalError(t *testing.T) {
+	r := bytes.NewReader([]byte("test error text"))
+	_, err := getFacebookQueryResponse(r)
+	assert.True(t, errors.Is(err, ErrUnmarshal))
+	assert.Contains(t, err.Error(), "test error text")
+}

unmarshal_error.go

@@ -0,0 +1,47 @@
+package messenger
+
+import (
+	"errors"
+	"fmt"
+	"io"
+	"io/ioutil"
+)
+
+var ErrUnmarshal = errors.New("unmarshal error")
+
+type UnmarshalError struct {
+	Content   []byte
+	ErrorText string
+	Err       error
+}
+
+func (u *UnmarshalError) Error() string {
+	return fmt.Sprintf("can not unmarshal content: %s; error: %s", string(u.Content), u.ErrorText)
+}
+
+func (u *UnmarshalError) Unwrap() error {
+	return u.Err
+}
+
+func NewUnmarshalError(err error) *UnmarshalError {
+	return &UnmarshalError{
+		Err:       ErrUnmarshal,
+		ErrorText: err.Error(),
+	}
+}
+
+func (u *UnmarshalError) WithReader(reader io.Reader) *UnmarshalError {
+	content, _ := ioutil.ReadAll(reader)
+	u.Content = content
+	return u
+}
+
+func (u *UnmarshalError) WithContent(content []byte) *UnmarshalError {
+	u.Content = content
+	return u
+}
+
+func (u *UnmarshalError) WithErr(err error) *UnmarshalError {
+	u.Err = err
+	return u
+}

unmarshal_error_test.go

@@ -0,0 +1,57 @@
+package messenger
+
+import (
+	"bytes"
+	"errors"
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+)
+
+func TestNewUnmarshalError(t *testing.T) {
+	err := errors.New("some error")
+	unmarshalError := NewUnmarshalError(err)
+	assert.True(t, errors.Is(unmarshalError, ErrUnmarshal))
+}
+
+func TestUnmarshalError_Error(t *testing.T) {
+	err := errors.New("some error")
+	content := []byte("test content")
+	actual := NewUnmarshalError(err).WithContent(content).Error()
+	expected := "can not unmarshal content: test content; error: some error"
+	assert.Equal(t, expected, actual)
+}
+
+func TestUnmarshalError_Unwrap(t *testing.T) {
+	err := errors.New("some error")
+	actual := NewUnmarshalError(err).Unwrap()
+	expected := ErrUnmarshal
+	assert.Equal(t, expected, actual)
+}
+
+func TestUnmarshalError_WithContent(t *testing.T) {
+	err := errors.New("some error")
+	content := []byte("test content")
+
+	actual := NewUnmarshalError(err).WithContent(content)
+	expected := &UnmarshalError{Err: ErrUnmarshal, Content: content, ErrorText: err.Error()}
+	assert.Equal(t, expected, actual)
+}
+
+func TestUnmarshalError_WithReader(t *testing.T) {
+	err := errors.New("some error")
+	content := []byte("test content")
+	reader := bytes.NewReader(content)
+
+	actual := NewUnmarshalError(err).WithReader(reader)
+	expected := &UnmarshalError{Err: ErrUnmarshal, Content: content, ErrorText: err.Error()}
+	assert.Equal(t, expected, actual)
+}
+
+func TestUnmarshalError_WithErr(t *testing.T) {
+	someError := errors.New("some error")
+	otherError := errors.New("other error")
+	actual := NewUnmarshalError(someError).WithErr(otherError)
+	expected := &UnmarshalError{Err: otherError, ErrorText: someError.Error()}
+	assert.Equal(t, expected, actual)
+}