API: Add File.AttachmentURI for convenience

Author: diamondburned

api/send.go

@@ -102,6 +102,8 @@ type SendMessageData struct {
 	// Embed is embedded rich content.
 	Embed *discord.Embed `json:"embed,omitempty"`
 
+	// Files is the list of file attachments to be uploaded. To reference a file
+	// in an embed, use (sendpart.File).AttachmentURI().
 	Files []sendpart.File `json:"-"`
 
 	// AllowedMentions are the allowed mentions for a message.

utils/sendpart/sendpart.go

@@ -3,6 +3,7 @@ package sendpart
 import (
 	"io"
 	"mime/multipart"
+	"net/url"
 	"strconv"
 
 	"github.com/diamondburned/arikawa/v2/utils/httputil"
@@ -16,6 +17,16 @@ type File struct {
 	Reader io.Reader
 }
 
+// AttachmentURI returns the file encoded using the attachment URI required for
+// embedding an attachment image.
+func (f File) AttachmentURI() string {
+	u := url.URL{
+		Scheme: "attachment",
+		Path:   f.Name,
+	}
+	return u.String()
+}
+
 // DataMultipartWriter is a MultipartWriter that also contains data that's
 // JSON-marshalable.
 type DataMultipartWriter interface {