From 3a5c233122c333a0b7a3834092574d9b90df9d32 Mon Sep 17 00:00:00 2001
From: Simon Backx <simon@ghost.org>
Date: Tue, 26 Sep 2023 16:25:03 +0200
Subject: [PATCH] =?UTF-8?q?=F0=9F=90=9B=20Fixed=20staff=20emails=20eventua?=
 =?UTF-8?q?lly=20having=20invalid=20styles=20(#18363)?=
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

fixes https://github.com/TryGhost/Ghost/issues/17937

- We used a global Handlebars instance, which means it was reused across
Ghost
- Partials are different between parts of Ghost, that means the partials
were overwritten every time a normal Mailgun email was send
- All staff emails send after a normal newsletter would have invalid
styles because the partials for styles were overwritten
---
 .../services/comments/CommentsServiceEmails.js      |  2 +-
 ghost/email-service/lib/EmailRenderer.js            |  2 +-
 ghost/staff-service/lib/StaffServiceEmails.js       | 13 ++++++++-----
 3 files changed, 10 insertions(+), 7 deletions(-)

diff --git a/ghost/core/core/server/services/comments/CommentsServiceEmails.js b/ghost/core/core/server/services/comments/CommentsServiceEmails.js
index c5fbe9e784..252ec07473 100644
--- a/ghost/core/core/server/services/comments/CommentsServiceEmails.js
+++ b/ghost/core/core/server/services/comments/CommentsServiceEmails.js
@@ -15,7 +15,7 @@ class CommentsServiceEmails {
         this.urlService = urlService;
         this.urlUtils = urlUtils;
 
-        this.Handlebars = require('handlebars');
+        this.Handlebars = require('handlebars').create();
     }
 
     async notifyPostAuthors(comment) {
diff --git a/ghost/email-service/lib/EmailRenderer.js b/ghost/email-service/lib/EmailRenderer.js
index ad037c4b36..5c22ef0972 100644
--- a/ghost/email-service/lib/EmailRenderer.js
+++ b/ghost/email-service/lib/EmailRenderer.js
@@ -668,7 +668,7 @@ class EmailRenderer {
     }
 
     async renderTemplate(data) {
-        this.#handlebars = require('handlebars');
+        this.#handlebars = require('handlebars').create();
 
         // Helpers
         this.#handlebars.registerHelper('if', function (conditional, options) {
diff --git a/ghost/staff-service/lib/StaffServiceEmails.js b/ghost/staff-service/lib/StaffServiceEmails.js
index 75f1657d0b..516c84d31c 100644
--- a/ghost/staff-service/lib/StaffServiceEmails.js
+++ b/ghost/staff-service/lib/StaffServiceEmails.js
@@ -13,8 +13,9 @@ class StaffServiceEmails {
         this.urlUtils = urlUtils;
         this.labs = labs;
 
-        this.Handlebars = require('handlebars');
+        this.Handlebars = require('handlebars').create();
         this.registerPartials();
+        this.registerHelpers();
     }
 
     async notifyFreeMemberSignup({
@@ -478,10 +479,7 @@ class StaffServiceEmails {
         });
     }
 
-    async renderHTML(templateName, data) {
-        const htmlTemplateSource = await fs.readFile(path.join(__dirname, './email-templates/', `${templateName}.hbs`), 'utf8');
-        const htmlTemplate = this.Handlebars.compile(Buffer.from(htmlTemplateSource).toString());
-
+    registerHelpers() {
         this.Handlebars.registerHelper('eq', function (arg, value, options) {
             if (arg === value) {
                 return options.fn(this);
@@ -496,6 +494,11 @@ class StaffServiceEmails {
             }
             return array.slice(0,limit);
         });
+    }
+
+    async renderHTML(templateName, data) {
+        const htmlTemplateSource = await fs.readFile(path.join(__dirname, './email-templates/', `${templateName}.hbs`), 'utf8');
+        const htmlTemplate = this.Handlebars.compile(Buffer.from(htmlTemplateSource).toString());
 
         let sharedData = {};
         if (data.recipient) {