From b9e2c79ebb05e2d671f4310bab8e3f19d1d82f09 Mon Sep 17 00:00:00 2001
From: Timothy Flynn <trflynn89@pm.me>
Date: Mon, 24 Mar 2025 15:52:41 -0400
Subject: [PATCH] LibWeb: Pass along the init dictionary for error / buffer
 change events

Otherwise, information stored in the base event init dictionary will be
dropped.
---
 Libraries/LibWeb/HTML/ErrorEvent.cpp              |  2 +-
 .../MediaSourceExtensions/BufferedChangeEvent.cpp |  4 ++--
 .../Text/expected/DOM/cancelable-events.txt       |  4 ++++
 .../wpt-import/dom/events/event-global.txt        |  5 ++---
 .../LibWeb/Text/input/DOM/cancelable-events.html  | 15 +++++++++++++++
 5 files changed, 24 insertions(+), 6 deletions(-)
 create mode 100644 Tests/LibWeb/Text/expected/DOM/cancelable-events.txt
 create mode 100644 Tests/LibWeb/Text/input/DOM/cancelable-events.html

diff --git a/Libraries/LibWeb/HTML/ErrorEvent.cpp b/Libraries/LibWeb/HTML/ErrorEvent.cpp
index 76a19b02d78..dc8a3bffa82 100644
--- a/Libraries/LibWeb/HTML/ErrorEvent.cpp
+++ b/Libraries/LibWeb/HTML/ErrorEvent.cpp
@@ -25,7 +25,7 @@ WebIDL::ExceptionOr<GC::Ref<ErrorEvent>> ErrorEvent::construct_impl(JS::Realm& r
 }
 
 ErrorEvent::ErrorEvent(JS::Realm& realm, FlyString const& event_name, ErrorEventInit const& event_init)
-    : DOM::Event(realm, event_name)
+    : DOM::Event(realm, event_name, event_init)
     , m_message(event_init.message)
     , m_filename(event_init.filename)
     , m_lineno(event_init.lineno)
diff --git a/Libraries/LibWeb/MediaSourceExtensions/BufferedChangeEvent.cpp b/Libraries/LibWeb/MediaSourceExtensions/BufferedChangeEvent.cpp
index bddb8402fb8..529c178a757 100644
--- a/Libraries/LibWeb/MediaSourceExtensions/BufferedChangeEvent.cpp
+++ b/Libraries/LibWeb/MediaSourceExtensions/BufferedChangeEvent.cpp
@@ -17,8 +17,8 @@ WebIDL::ExceptionOr<GC::Ref<BufferedChangeEvent>> BufferedChangeEvent::construct
     return realm.create<BufferedChangeEvent>(realm, type, event_init);
 }
 
-BufferedChangeEvent::BufferedChangeEvent(JS::Realm& realm, AK::FlyString const& type, BufferedChangeEventInit const&)
-    : DOM::Event(realm, type)
+BufferedChangeEvent::BufferedChangeEvent(JS::Realm& realm, AK::FlyString const& type, BufferedChangeEventInit const& event_init)
+    : DOM::Event(realm, type, event_init)
 {
 }
 
diff --git a/Tests/LibWeb/Text/expected/DOM/cancelable-events.txt b/Tests/LibWeb/Text/expected/DOM/cancelable-events.txt
new file mode 100644
index 00000000000..869bb0d4db8
--- /dev/null
+++ b/Tests/LibWeb/Text/expected/DOM/cancelable-events.txt
@@ -0,0 +1,4 @@
+event=test1 cancelable=false
+event=test2 cancelable=true
+event=test3 cancelable=false
+event=test4 cancelable=true
diff --git a/Tests/LibWeb/Text/expected/wpt-import/dom/events/event-global.txt b/Tests/LibWeb/Text/expected/wpt-import/dom/events/event-global.txt
index 8690e08a540..d32db710d3b 100644
--- a/Tests/LibWeb/Text/expected/wpt-import/dom/events/event-global.txt
+++ b/Tests/LibWeb/Text/expected/wpt-import/dom/events/event-global.txt
@@ -2,13 +2,12 @@ Harness status: OK
 
 Found 8 tests
 
-7 Pass
-1 Fail
+8 Pass
 Pass	event exists on window, which is initially set to undefined
 Pass	window.event is only defined during dispatch
 Pass	window.event is undefined if the target is in a shadow tree (event dispatched outside shadow tree)
 Pass	window.event is undefined if the target is in a shadow tree (event dispatched inside shadow tree)
-Fail	window.event is undefined inside window.onerror if the target is in a shadow tree (ErrorEvent dispatched inside shadow tree)
+Pass	window.event is undefined inside window.onerror if the target is in a shadow tree (ErrorEvent dispatched inside shadow tree)
 Pass	window.event is set to the current event during dispatch
 Pass	window.event is set to the current event, which is the event passed to dispatch
 Pass	window.event is set to the current event, which is the event passed to dispatch (2)
\ No newline at end of file
diff --git a/Tests/LibWeb/Text/input/DOM/cancelable-events.html b/Tests/LibWeb/Text/input/DOM/cancelable-events.html
new file mode 100644
index 00000000000..cb137196c70
--- /dev/null
+++ b/Tests/LibWeb/Text/input/DOM/cancelable-events.html
@@ -0,0 +1,15 @@
+<!DOCTYPE html>
+<script src="../include.js"></script>
+<script>
+    test(() => {
+        const printEvent = event => {
+            println(`event=${event.type} cancelable=${event.cancelable}`);
+        };
+
+        printEvent(new ErrorEvent("test1"));
+        printEvent(new ErrorEvent("test2", { cancelable: true }));
+
+        printEvent(new BufferedChangeEvent("test3"));
+        printEvent(new BufferedChangeEvent("test4", { cancelable: true }));
+    });
+</script>