fix(core): always report the first error on unhandled rejection (#18992)

The root cause of denoland/deno_std#3320, I believe, is that
`pending_promise_rejections` is a `HashMap` whose entries are in
arbitrary order, and as a result either of the two errors (`AddrInUse`
and `TypeError`) may be selected when determining which one to report. I
changed the field to a `VecDeque` so that the first error (`AddrInUse`
in this case) is always selected.

1 files changed, 18 insertions, 1 deletions

diff --git a/core/runtime.rs b/core/runtime.rs
index 8c78be55b..bb77bb25a 100644
--- a/core/runtime.rs
+++ b/core/runtime.rs
@@ -1831,7 +1831,7 @@ impl JsRuntime {
             .state(tc_scope)
             .borrow_mut()
             .pending_promise_rejections
-            .remove(&promise_global);
+            .retain(|(key, _)| key != &promise_global);
         }
       }
       let promise_global = v8::Global::new(tc_scope, promise);
@@ -4139,6 +4139,23 @@ Deno.core.opAsync("op_async_serialize_object_with_numbers_as_keys", {
   }
 
   #[tokio::test]
+  async fn test_unhandled_rejection_order() {
+    let mut runtime = JsRuntime::new(Default::default());
+    runtime
+      .execute_script_static(
+        "",
+        r#"
+        for (let i = 0; i < 100; i++) {
+          Promise.reject(i);
+        }
+        "#,
+      )
+      .unwrap();
+    let err = runtime.run_event_loop(false).await.unwrap_err();
+    assert_eq!(err.to_string(), "Uncaught (in promise) 0");
+  }
+
+  #[tokio::test]
   async fn test_set_promise_reject_callback() {
     static PROMISE_REJECT: AtomicUsize = AtomicUsize::new(0);