From 9beb4b7f2090cac99a622bffe41cf2b7e731d60a Mon Sep 17 00:00:00 2001
From: Sebastian Sebbie Silbermann <sebastian.silbermann@vercel.com>
Date: Tue, 29 Apr 2025 15:17:07 +0200
Subject: [PATCH] [toolbox-optimizer] Fix crash if `<template>` is the very
 last element

---
 .../optimizer/lib/transformers/OptimizeAmpBind.js   |  6 +++++-
 .../template_last/expected_output.html              | 13 +++++++++++++
 .../valid/OptimizeAmpBind/template_last/input.html  | 11 +++++++++++
 3 files changed, 29 insertions(+), 1 deletion(-)
 create mode 100644 packages/optimizer/spec/transformers/valid/OptimizeAmpBind/template_last/expected_output.html
 create mode 100644 packages/optimizer/spec/transformers/valid/OptimizeAmpBind/template_last/input.html
diff --git a/packages/optimizer/lib/transformers/OptimizeAmpBind.js b/packages/optimizer/lib/transformers/OptimizeAmpBind.js
index 565249b8f..d14a85ff1 100644
--- a/packages/optimizer/lib/transformers/OptimizeAmpBind.js
+++ b/packages/optimizer/lib/transformers/OptimizeAmpBind.js
@@ -43,7 +43,11 @@ class OptimizeAmpBind {
     for (let node = html; node !== null; node = nextNode(node)) {
       if (isTemplate(node)) {
         node = skipNodeAndChildren(node);
-        continue;
+        if (node === null) {
+          break;
+        } else {
+          continue;
+        }
       }
 
       const {attribs} = node;
diff --git a/packages/optimizer/spec/transformers/valid/OptimizeAmpBind/template_last/expected_output.html b/packages/optimizer/spec/transformers/valid/OptimizeAmpBind/template_last/expected_output.html
new file mode 100644
index 000000000..a4a7fa942
--- /dev/null
+++ b/packages/optimizer/spec/transformers/valid/OptimizeAmpBind/template_last/expected_output.html
@@ -0,0 +1,13 @@
+<!doctype html>
+<html ⚡ i-amphtml-binding>
+<head>
+  <meta charset="utf-8">
+  <meta name="viewport" content="width=device-width,minimum-scale=1">
+  <script async src="https://cdn.ampproject.org/v0.js"></script>
+  <script async custom-element="amp-bind" src="https://cdn.ampproject.org/v0/amp-bind-0.1.js"></script>
+</head>
+<body>
+  <div data-amp-bind-text="foo" i-amphtml-binding>Hello, AMP world.</div>
+  <template id="my-template">Must be the very last element. Whitespace after closing tag would alter the test.</template>
+</body>
+</html>
\ No newline at end of file
diff --git a/packages/optimizer/spec/transformers/valid/OptimizeAmpBind/template_last/input.html b/packages/optimizer/spec/transformers/valid/OptimizeAmpBind/template_last/input.html
new file mode 100644
index 000000000..2e7008f8a
--- /dev/null
+++ b/packages/optimizer/spec/transformers/valid/OptimizeAmpBind/template_last/input.html
@@ -0,0 +1,11 @@
+<!doctype html>
+<html ⚡>
+<head>
+  <meta charset="utf-8">
+  <meta name="viewport" content="width=device-width,minimum-scale=1">
+  <script async src="https://cdn.ampproject.org/v0.js"></script>
+  <script async custom-element="amp-bind" src="https://cdn.ampproject.org/v0/amp-bind-0.1.js"></script>
+</head>
+<body>
+    <div data-amp-bind-text="foo">Hello, AMP world.</div>
+    <template id="my-template">Must be the very last element. Whitespace after closing tag would alter the test.</template></body></html>
