Add reaction events to websocket API

item.go

@@ -11,11 +11,12 @@ const (
 
 // Item is any type of slack message - message, file, or file comment.
 type Item struct {
-	Type    string   `json:"type"`
-	Channel string   `json:"channel,omitempty"`
-	Message *Message `json:"message,omitempty"`
-	File    *File    `json:"file,omitempty"`
-	Comment *Comment `json:"comment,omitempty"`
+	Type      string   `json:"type"`
+	Channel   string   `json:"channel,omitempty"`
+	Message   *Message `json:"message,omitempty"`
+	File      *File    `json:"file,omitempty"`
+	Comment   *Comment `json:"comment,omitempty"`
+	Timestamp string   `json:"ts,omitempty"`
 }
 
 // NewMessageItem turns a message on a channel into a typed message struct.

websocket.go

@@ -262,6 +262,9 @@ func callEvent(eventType string, ch chan SlackEvent, event json.RawMessage) {
 		"file_comment_edited":  &FileCommentEditedEvent{},
 		"file_comment_deleted": &FileCommentDeletedEvent{},
 
+		"reaction_added":   &ReactionAddedEvent{},
+		"reaction_removed": &ReactionAddedEvent{},
+
 		"star_added":   &StarAddedEvent{},
 		"star_removed": &StarRemovedEvent{},
 

websocket_reactions.go

@@ -0,0 +1,11 @@
+package slack
+
+type reactionEvent struct {
+	Type           string         `json:"type"`
+	UserId         string         `json:"user"`
+	Item           ReactedItem    `json:"item"`
+	Reaction       string         `json:"reaction"`
+	EventTimestamp JSONTimeString `json:"event_ts"`
+}
+type ReactionAddedEvent reactionEvent
+type ReactionRemovedEvent reactionEvent