From 0f493e9baf281c4c754cf48476aa3a27f91342c2 Mon Sep 17 00:00:00 2001
From: Benjamin Gruenbaum <benjamingr@gmail.com>
Date: Mon, 24 Jan 2022 20:47:11 +0200
Subject: [PATCH] process: unhandledRejection support more errors

Support cross realm errors where `instanceof` errors in our
unhandledRejection warning to print better error with stack traces.
---
 lib/internal/process/promises.js | 16 ++++++++++++----
 1 file changed, 12 insertions(+), 4 deletions(-)

diff --git a/lib/internal/process/promises.js b/lib/internal/process/promises.js
index 76099b1032a466..49445d258febe7 100644
--- a/lib/internal/process/promises.js
+++ b/lib/internal/process/promises.js
@@ -5,6 +5,7 @@ const {
   ArrayPrototypeShift,
   Error,
   ObjectDefineProperty,
+  ObjectPrototypeHasOwnProperty,
   SafeWeakMap,
 } = primordials;
 
@@ -179,14 +180,21 @@ function emitUnhandledRejectionWarning(uid, reason) {
       `(rejection id: ${uid})`
   );
   try {
-    if (reason instanceof Error) {
+    if (ObjectPrototypeHasOwnProperty(reason, 'stack')) {
       warning.stack = reason.stack;
       process.emitWarning(reason.stack, unhandledRejectionErrName);
     } else {
       process.emitWarning(
         noSideEffectsToString(reason), unhandledRejectionErrName);
     }
-  } catch {}
+  } catch {
+    try {
+      process.emitWarning(
+        noSideEffectsToString(reason), unhandledRejectionErrName);
+    } catch {
+      // Ignore.
+    }
+  }
 
   process.emitWarning(warning);
 }
@@ -232,7 +240,7 @@ function processPromiseRejections() {
     try {
       switch (unhandledRejectionsMode) {
         case kStrictUnhandledRejections: {
-          const err = reason instanceof Error ?
+          const err = ObjectPrototypeHasOwnProperty(reason, 'stack') ?
             reason : generateUnhandledRejectionError(reason);
           // This destroys the async stack, don't clear it after
           triggerUncaughtException(err, true /* fromPromise */);
@@ -259,7 +267,7 @@ function processPromiseRejections() {
         case kThrowUnhandledRejections: {
           const handled = emit(reason, promise, promiseInfo);
           if (!handled) {
-            const err = reason instanceof Error ?
+            const err = ObjectPrototypeHasOwnProperty(reason, 'stack') ?
               reason : generateUnhandledRejectionError(reason);
               // This destroys the async stack, don't clear it after
             triggerUncaughtException(err, true /* fromPromise */);