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, 48 insertions, 0 deletions

diff --git a/core/ops_builtin_v8.rs b/core/ops_builtin_v8.rs
index 4bc80faa5..8af50f860 100644
--- a/core/ops_builtin_v8.rs
+++ b/core/ops_builtin_v8.rs
@@ -48,6 +48,9 @@ pub(crate) fn init_builtins_v8() -> Vec<OpDecl> {
     op_apply_source_map::decl(),
     op_set_format_exception_callback::decl(),
     op_event_loop_has_more_work::decl(),
+    op_store_pending_promise_exception::decl(),
+    op_remove_pending_promise_exception::decl(),
+    op_has_pending_promise_exception::decl(),
   ]
 }
 
@@ -810,3 +813,48 @@ fn op_event_loop_has_more_work(scope: &mut v8::HandleScope) -> bool {
     || has_pending_background_tasks
     || has_tick_scheduled
 }
+
+#[op(v8)]
+fn op_store_pending_promise_exception<'a>(
+  scope: &mut v8::HandleScope<'a>,
+  promise: serde_v8::Value<'a>,
+  reason: serde_v8::Value<'a>,
+) {
+  let state_rc = JsRuntime::state(scope);
+  let mut state = state_rc.borrow_mut();
+  let promise_value =
+    v8::Local::<v8::Promise>::try_from(promise.v8_value).unwrap();
+  let promise_global = v8::Global::new(scope, promise_value);
+  let error_global = v8::Global::new(scope, reason.v8_value);
+  state
+    .pending_promise_exceptions
+    .insert(promise_global, error_global);
+}
+
+#[op(v8)]
+fn op_remove_pending_promise_exception<'a>(
+  scope: &mut v8::HandleScope<'a>,
+  promise: serde_v8::Value<'a>,
+) {
+  let state_rc = JsRuntime::state(scope);
+  let mut state = state_rc.borrow_mut();
+  let promise_value =
+    v8::Local::<v8::Promise>::try_from(promise.v8_value).unwrap();
+  let promise_global = v8::Global::new(scope, promise_value);
+  state.pending_promise_exceptions.remove(&promise_global);
+}
+
+#[op(v8)]
+fn op_has_pending_promise_exception<'a>(
+  scope: &mut v8::HandleScope<'a>,
+  promise: serde_v8::Value<'a>,
+) -> bool {
+  let state_rc = JsRuntime::state(scope);
+  let state = state_rc.borrow();
+  let promise_value =
+    v8::Local::<v8::Promise>::try_from(promise.v8_value).unwrap();
+  let promise_global = v8::Global::new(scope, promise_value);
+  state
+    .pending_promise_exceptions
+    .contains_key(&promise_global)
+}