test: introduce common.crashOnUnhandledRejection

Ref: #12442 PR-URL: #12489 Backport-PR-URL: #13103 Reviewed-By: Matthew Loring <mattloring@google.com> Reviewed-By: Julien Gilli <jgilli@nodejs.org> Reviewed-By: Benjamin Gruenbaum <benjamingr@gmail.com> Reviewed-By: James M Snell <jasnell@gmail.com>

Author: addaleax

test/common.js

@@ -552,3 +552,9 @@ exports.expectWarning = function(name, expected) {
  expected.splice(expected.indexOf(warning.message), 1);
  }, expected.length));
 };
+
+// Crash the process on unhandled rejections.
+exports.crashOnUnhandledRejection = function() {
+ process.on('unhandledRejection',
+ (err) => process.nextTick(() => { throw err; }));
+};