fix: unhandledrejection handling for sync throw in top level (#15279)

Fixes an edge in "unhandledrejection" event that prevent synchronous
errors being surfaced when throw from a top-level scope.

2 files changed, 11 insertions, 1 deletions

diff --git a/core/bindings.rs b/core/bindings.rs
index 6fa9f745b..a93a3e746 100644
--- a/core/bindings.rs
+++ b/core/bindings.rs
@@ -363,6 +363,8 @@ pub extern "C" fn promise_reject_callback(message: v8::PromiseRejectMessage) {
       }
     }
 
+    // TODO(bartlomieju): remove this whole block, `js_uncaught_exception_cb` is
+    // not needed anymore
     if let Some(exception) = tc_scope.exception() {
       if let Some(js_uncaught_exception_cb) = js_uncaught_exception_cb {
         tc_scope.reset(); // Cancel pending exception.
diff --git a/core/runtime.rs b/core/runtime.rs
index 64e7f635c..4568f2018 100644
--- a/core/runtime.rs
+++ b/core/runtime.rs
@@ -1335,7 +1335,15 @@ impl JsRuntime {
         .expect("Expected to get promise as module evaluation result");
       let promise_global = v8::Global::new(tc_scope, promise);
       let mut state = state_rc.borrow_mut();
-      state.pending_promise_exceptions.remove(&promise_global);
+      {
+        let pending_mod_evaluate = state.pending_mod_evaluate.as_ref().unwrap();
+        let pending_rejection_was_already_handled = pending_mod_evaluate
+          .handled_promise_rejections
+          .contains(&promise_global);
+        if !pending_rejection_was_already_handled {
+          state.pending_promise_exceptions.remove(&promise_global);
+        }
+      }
       let promise_global = v8::Global::new(tc_scope, promise);
       state.pending_mod_evaluate.as_mut().unwrap().promise =
         Some(promise_global);