1 files changed, 8 insertions, 1 deletions
diff --git a/cli/tests/testdata/run/onload/main.ts b/cli/tests/testdata/run/onload/main.ts
index 798b8aa7b..126627e34 100644
--- a/cli/tests/testdata/run/onload/main.ts
+++ b/cli/tests/testdata/run/onload/main.ts
@@ -6,12 +6,14 @@ assert(window.hasOwnProperty("onload"));
 assert(window.onload === null);
 
 const eventHandler = (e: Event) => {
-  assert(!e.cancelable);
+  assert(e.type === "beforeunload" ? e.cancelable : !e.cancelable);
   console.log(`got ${e.type} event in event handler (main)`);
 };
 
 window.addEventListener("load", eventHandler);
 
+window.addEventListener("beforeunload", eventHandler);
+
 window.addEventListener("unload", eventHandler);
 
 window.onload = (e: Event) => {
@@ -19,6 +21,11 @@ window.onload = (e: Event) => {
   console.log(`got ${e.type} event in onload function`);
 };
 
+window.onbeforeunload = (e: BeforeUnloadEvent) => {
+  assert(e.cancelable);
+  console.log(`got ${e.type} event in onbeforeunload function`);
+};
+
 window.onunload = (e: Event) => {
   assert(!e.cancelable);
   console.log(`got ${e.type} event in onunload function`);