backport: RichEmbed#attachFiles

src/structures/RichEmbed.js

@@ -72,6 +72,12 @@ class RichEmbed {
      * @type {FileOptions|string|Attachment}
      */
     this.file = data.file;
+
+    /**
+     * The files to upload alongside this Embed
+     * @type {Array<FileOptions|string|Attachment>}
+     */
+    this.files = [];
   }
 
   /**
@@ -216,6 +222,18 @@ class RichEmbed {
     return this;
   }
 
+  /**
+   * Sets the files to upload alongside the embed. A file can be accessed via `attachment://fileName.extension` when
+   * setting an embed image or author/footer icons. Multiple files can be attached.
+   * @param {Array<FileOptions|string|Attachment>} files Files to attach
+   * @returns {RichEmbed}
+   */
+  attachFiles(files) {
+    files = files.map(file => file instanceof Attachment ? file.file : file);
+    this.files = this.files.concat(files);
+    return this;
+  }
+
   /**
    * Transforms the embed object to be processed.
    * @returns {Object} The raw data of this embed

src/structures/interfaces/TextBasedChannel.js

@@ -125,9 +125,15 @@ class TextBasedChannel {
     }
     options.reply = reply;
 
-    if (options.embed && options.embed.file) {
+    if (options.embed) {
-      if (options.files) options.files.push(options.embed.file);
+      if (options.embed.file) {
-      else options.files = [options.embed.file];
+        if (options.files) options.files.push(options.embed.file);
+        else options.files = [options.embed.file];
+      }
+      if (options.embed.files) {
+        if (options.files) options.files = options.files.concat(options.embed.files);
+        else options.files = options.embed.files;
+      }
     }
 
     if (options.file) {