From dec0a3b3e5de9c99dd9e066aa63e596c6a9ac96c Mon Sep 17 00:00:00 2001
From: Davy Dequidt <3024137+ddequidt@users.noreply.github.com>
Date: Fri, 16 May 2025 17:29:14 +0200
Subject: [PATCH] #468 fix DeprecationWarning: Calling promisify on a function
 that returns a Promise is likely a mistake.

---
 index.js | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/index.js b/index.js
index e012f41..3972876 100644
--- a/index.js
+++ b/index.js
@@ -9,6 +9,7 @@ const getPaths = require('get-paths');
 const { convert } = require('html-to-text');
 const juice = require('juice');
 const nodemailer = require('nodemailer');
+const { isPromise } = require('util/types');
 
 let previewEmail;
 
@@ -251,7 +252,11 @@ class Email {
       if (locale !== locals.locale) i18n.setLocale(locals.locale);
     }
 
-    const res = await util.promisify(renderFn)(filePath, locals);
+    const res = await (isPromise(
+      Reflect.apply(renderFn, this, [filePath, locals])
+    )
+      ? renderFn(filePath, locals)
+      : util.promisify(renderFn)(filePath, locals));
     // transform the html with juice using remote paths
     // google now supports media queries
     // https://developers.google.com/gmail/design/reference/supported_css