From b7abe3d4a5f4bf00fc8af503c2fb358745ff855b Mon Sep 17 00:00:00 2001
From: Domenic Denicola <domenic@chromium.org>
Date: Thu, 17 Jul 2025 21:21:15 -0700
Subject: [PATCH] Fire error events for invalid speculation rules

This CL introduces error handling for <script type=speculationrules>,
mirroring the behavior of <script type=importmap>.

Specifically, it adds error events for two cases:
- Inline speculation rules with unparsable JSON.
- External speculation rules, which are not yet supported.

This is verified by new web platform tests.

This follows the spec change at
https://github.com/whatwg/html/pull/11426.

Change-Id: I9b0776b86059f6c8734d57c17f50ed26e89215da
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/6758353
Reviewed-by: Hiroki Nakagawa <nhiroki@chromium.org>
Commit-Queue: Domenic Denicola <domenic@chromium.org>
Cr-Commit-Position: refs/heads/main@{#1488632}
---
 .../external-speculation-rules-errors.html    | 36 +++++++++++++++++++
 .../inline-speculation-rules-errors.html      | 36 +++++++++++++++++++
 speculation-rules/resources/empty.json        |  1 +
 3 files changed, 73 insertions(+)
 create mode 100644 speculation-rules/external-speculation-rules-errors.html
 create mode 100644 speculation-rules/inline-speculation-rules-errors.html
 create mode 100644 speculation-rules/resources/empty.json
diff --git a/speculation-rules/external-speculation-rules-errors.html b/speculation-rules/external-speculation-rules-errors.html
new file mode 100644
index 00000000000000..f97376f20b0c11
--- /dev/null
+++ b/speculation-rules/external-speculation-rules-errors.html
@@ -0,0 +1,36 @@
+<!DOCTYPE html>
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<script>
+  window.markupErrored = false;
+  window.markupLoaded = false;
+</script>
+<script src="resources/empty.json" type="speculationrules" onload="window.markupLoaded = true;" onerror="window.markupErrored = true;"></script>
+<script>
+promise_test(async () => {
+  await new Promise((resolve, reject) => {
+    const element = document.createElement("script");
+    element.onload = () => { reject("Got an unexpected load event"); };
+    element.onerror = () => { resolve("Got an error event"); };
+    element.src = "resources/empty.json";
+    element.type = "speculationrules";
+    document.head.appendChild(element);
+  })
+}, "Test that an external speculation rules script fires an error event");
+
+promise_test(async () => {
+  await new Promise((resolve, reject) => {
+    const element = document.createElement("script");
+    element.type = "speculationrules";
+    element.onload = () => { reject("Got an unexpected load event"); };
+    element.onerror = () => { resolve("Got an error event"); };
+    element.src = "resources/empty.json";
+    document.head.appendChild(element);
+  })
+}, "Test that an external speculation rules script fires an error event, regardless of attribute order");
+
+promise_test(async () => {
+  assert_true(window.markupErrored, "error");
+  assert_false(window.markupLoaded, "load");
+}, "Test that an external speculation rules script in markup fires an error event");
+</script>
diff --git a/speculation-rules/inline-speculation-rules-errors.html b/speculation-rules/inline-speculation-rules-errors.html
new file mode 100644
index 00000000000000..69e9cf3df5c6a1
--- /dev/null
+++ b/speculation-rules/inline-speculation-rules-errors.html
@@ -0,0 +1,36 @@
+<!DOCTYPE html>
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<script>
+setup({ allow_uncaught_exception: true });
+
+promise_test(async t => {
+  const script = document.createElement('script');
+  script.type = 'speculationrules';
+  script.textContent = 'invalid json';
+
+  const log = [];
+  const elementError = new Promise(resolve => {
+    script.addEventListener('error', e => {
+      assert_equals(e.constructor, Event, 'event should be a simple Event');
+      log.push('element error');
+      resolve();
+    }, { once: true });
+  });
+
+  const globalError = new Promise(resolve => {
+    window.addEventListener('error', e => {
+      e.preventDefault();
+      assert_equals(e.constructor, ErrorEvent, 'global event should be an ErrorEvent');
+      assert_equals(e.error.constructor, TypeError, 'e.error should be a TypeError');
+      log.push('global error');
+      resolve();
+    }, { once: true });
+  });
+
+  document.head.appendChild(script);
+
+  await Promise.all([elementError, globalError]);
+  assert_array_equals(log, ['element error', 'global error']);
+}, 'A script with invalid JSON should fire error events on the element and window');
+</script>
diff --git a/speculation-rules/resources/empty.json b/speculation-rules/resources/empty.json
new file mode 100644
index 00000000000000..9e26dfeeb6e641
--- /dev/null
+++ b/speculation-rules/resources/empty.json
@@ -0,0 +1 @@
+{}
\ No newline at end of file
