Add files to MessageEdit (bwmarrin#1253)

* Add files to MessageEdit

* Remove files from json

Co-authored-by: Fedor Lapshin <[email protected]>

Co-authored-by: Fedor Lapshin <[email protected]>

Author: ShadiestGoat

message.go

@@ -249,6 +249,10 @@ type MessageEdit struct {
 	Embeds          []*MessageEmbed         `json:"embeds"`
 	AllowedMentions *MessageAllowedMentions `json:"allowed_mentions,omitempty"`
 	Flags           MessageFlags            `json:"flags,omitempty"`
+	// Files to append to the message
+	Files []*File `json:"-"`
+	// Overwrite existing attachments
+	Attachments *[]*MessageAttachment `json:"attachments,omitempty"`
 
 	ID      string
 	Channel string

restapi.go

@@ -1729,7 +1729,19 @@ func (s *Session) ChannelMessageEditComplex(m *MessageEdit) (st *Message, err er
 			embed.Type = "rich"
 		}
 	}
-	response, err := s.RequestWithBucketID("PATCH", EndpointChannelMessage(m.Channel, m.ID), m, EndpointChannelMessage(m.Channel, ""))
+
+	endpoint := EndpointChannelMessage(m.Channel, m.ID)
+
+	var response []byte
+	if len(m.Files) > 0 {
+		contentType, body, encodeErr := MultipartBodyWithJSON(m, m.Files)
+		if encodeErr != nil {
+			return st, encodeErr
+		}
+		response, err = s.request("PATCH", endpoint, contentType, body, EndpointChannelMessage(m.Channel, ""), 0)
+	} else {
+		response, err = s.RequestWithBucketID("PATCH", endpoint, m, EndpointChannelMessage(m.Channel, ""))
+	}
 	if err != nil {
 		return
 	}