Add attachment to test email

Author: rajumsys

admin.widget.class.php

@@ -51,10 +51,13 @@ public function set_html_content_type()
     private function send_email($recipient)
     {
         add_filter('wp_mail_content_type', array($this, 'set_html_content_type'));
+        $headers = array();
+        $attachments= array(__DIR__ . '/sample.txt');
         $result = wp_mail($recipient,
             'SparkPost email test',
             '<h3>Hurray!!</h3><p>You\'ve got mail! <br/><br> Regards,<br/><a href="https://www.sparkpost.com">SparkPost</a> WordPress plugin</p>',
-            ''
+            $headers,
+            $attachments
         );
         remove_filter('wp_mail_content_type', array($this, 'set_html_content_type'));
         return $result;

sample.txt

@@ -0,0 +1 @@
+This is a sample file to be sent as an attachment.