feat(web): add beforeunload event (#14830)

This commit adds the 'beforeunload' event.

Co-authored-by: Bartek Iwańczuk <biwanczuk@gmail.com>

1 files changed, 21 insertions, 0 deletions

diff --git a/cli/tests/testdata/before_unload.js b/cli/tests/testdata/before_unload.js
new file mode 100644
index 000000000..2572e512b
--- /dev/null
+++ b/cli/tests/testdata/before_unload.js
@@ -0,0 +1,21 @@
+let count = 0;
+
+console.log("0");
+
+globalThis.addEventListener("beforeunload", (e) => {
+  console.log("GOT EVENT");
+  if (count === 0 || count === 1) {
+    e.preventDefault();
+    setTimeout(() => {
+      console.log("3");
+    }, 100);
+  }
+
+  count++;
+});
+
+console.log("1");
+
+setTimeout(() => {
+  console.log("2");
+}, 100);