Handle host errors captured in Promises

Author: XmiliaH

lib/setup-sandbox.js

@@ -439,23 +439,36 @@ global.eval = new LocalProxy(localEval, EvalHandler);
  * Promise sanitization
  */
 
-if (localPromise && !allowAsync) {
+if (localPromise) {
 
 	const PromisePrototype = localPromise.prototype;
 
-	overrideWithProxy(PromisePrototype, 'then', PromisePrototype.then, AsyncErrorHandler);
-	// This seems not to work, and will produce
-	// UnhandledPromiseRejectionWarning: TypeError: Method Promise.prototype.then called on incompatible receiver [object Object].
-	// This is likely caused since the host.Promise.prototype.then cannot use the VM Proxy object.
-	// Contextify.connect(host.Promise.prototype.then, Promise.prototype.then);
+	if (!allowAsync) {
+
+		overrideWithProxy(PromisePrototype, 'then', PromisePrototype.then, AsyncErrorHandler);
+		// This seems not to work, and will produce
+		// UnhandledPromiseRejectionWarning: TypeError: Method Promise.prototype.then called on incompatible receiver [object Object].
+		// This is likely caused since the host.Promise.prototype.then cannot use the VM Proxy object.
+		// Contextify.connect(host.Promise.prototype.then, Promise.prototype.then);
+
+	} else {
+
+		overrideWithProxy(PromisePrototype, 'then', PromisePrototype.then, {
+			__proto__: null,
+			apply(target, thiz, args) {
+				if (args.length > 1) {
+					const onRejected = args[1];
+					if (typeof onRejected === 'function') {
+						args[1] = function wrapper(error) {
+							error = ensureThis(error);
+							return localReflectApply(onRejected, this, [error]);
+						};
+					}
+				}
+				return localReflectApply(target, thiz, args);
+			}
+		});
 
-	if (PromisePrototype.finally) {
-		overrideWithProxy(PromisePrototype, 'finally', PromisePrototype.finally, AsyncErrorHandler);
-		// Contextify.connect(host.Promise.prototype.finally, Promise.prototype.finally);
-	}
-	if (Promise.prototype.catch) {
-		overrideWithProxy(PromisePrototype, 'catch', PromisePrototype.catch, AsyncErrorHandler);
-		// Contextify.connect(host.Promise.prototype.catch, Promise.prototype.catch);
 	}
 
 }