feat: add "unhandledrejection" event support (#12994)

This commit adds support for "unhandledrejection" event.

This event will trigger event listeners registered using:

"globalThis.addEventListener("unhandledrejection")
"globalThis.onunhandledrejection"
This is done by registering a default handler using
"Deno.core.setPromiseRejectCallback" that allows to
handle rejected promises in JavaScript instead of Rust.

This commit will make it possible to polyfill
"process.on("unhandledRejection")" in the Node compat
layer.

Co-authored-by: Colin Ihrig <cjihrig@gmail.com>

1 files changed, 11 insertions, 0 deletions

diff --git a/cli/tests/testdata/unhandled_rejection.js b/cli/tests/testdata/unhandled_rejection.js
new file mode 100644
index 000000000..352e861b4
--- /dev/null
+++ b/cli/tests/testdata/unhandled_rejection.js
@@ -0,0 +1,11 @@
+globalThis.addEventListener("unhandledrejection", (e) => {
+  console.log("unhandled rejection at:", e.promise, "reason:", e.reason);
+  e.preventDefault();
+});
+
+function Foo() {
+  this.bar = Promise.reject(new Error("bar not available"));
+}
+
+new Foo();
+Promise.reject();