From 07d3724a46de3c570bf07313b006cb3c0c713b8c Mon Sep 17 00:00:00 2001
From: Alan Willms <dyulax@gmail.com>
Date: Mon, 23 Mar 2020 16:43:20 -0300
Subject: [PATCH] Fix bug when data layer name contains unexpected characters

---
 src/Snippets.js | 15 ++++++++-------
 1 file changed, 8 insertions(+), 7 deletions(-)

diff --git a/src/Snippets.js b/src/Snippets.js
index b798e3db..db8ea2c5 100644
--- a/src/Snippets.js
+++ b/src/Snippets.js
@@ -8,11 +8,11 @@ const Snippets = {
     const gtm_preview = `&gtm_preview=${preview}`
 
     if (!id) warn('GTM Id is required')
-    
+
     const iframe = `
       <iframe src="https://www.googletagmanager.com/ns.html?id=${id}${gtm_auth}${gtm_preview}&gtm_cookies_win=x"
         height="0" width="0" style="display:none;visibility:hidden" id="tag-manager"></iframe>`
-  
+
     const script = `
       (function(w,d,s,l,i){w[l]=w[l]||[];
         w[l].push({'gtm.start': new Date().getTime(),event:'gtm.js', ${JSON.stringify(events).slice(1, -1)}});
@@ -20,9 +20,9 @@ const Snippets = {
         j.async=true;j.src='https://www.googletagmanager.com/gtm.js?id='+i+dl+'${gtm_auth}${gtm_preview}&gtm_cookies_win=x';
         f.parentNode.insertBefore(j,f);
       })(window,document,'script','${dataLayerName}','${id}');`
-  
+
     const dataLayerVar = this.dataLayer(dataLayer, dataLayerName)
-  
+
     return {
       iframe,
       script,
@@ -30,10 +30,11 @@ const Snippets = {
     }
   },
   dataLayer: function (dataLayer, dataLayerName) {
+    const escapedDataLayerName = JSON.stringify(dataLayerName)
     return `
-      window.${dataLayerName} = window.${dataLayerName} || [];
-      window.${dataLayerName}.push(${JSON.stringify(dataLayer)})`
+      window[${escapedDataLayerName}] = window[${escapedDataLayerName}] || [];
+      window[${escapedDataLayerName}].push(${JSON.stringify(dataLayer)})`
   }
-}  
+}
 
 module.exports = Snippets