process: cast promise rejection reason to string

The unhandled promise rejection warning uses a template literal and
prints the reason a promise was rejected. If rejecting with a symbol,
the symbol failed to convert to a string and the process crashed. Now,
symbols are casted to strings and the process does not crash.

Fixes: https://github.com/nodejs/node/issues/11637
PR-URL: https://github.com/nodejs/node/pull/11640
Reviewed-By: Anna Henningsen <anna@addaleax.net>

1 files changed, 18 insertions, 0 deletions

diff --git a/test/parallel/test-promises-unhandled-symbol-rejections.js b/test/parallel/test-promises-unhandled-symbol-rejections.js
new file mode 100644
index 0000000000..a60a5f2e8a
--- /dev/null
+++ b/test/parallel/test-promises-unhandled-symbol-rejections.js
@@ -0,0 +1,18 @@
+'use strict';
+const common = require('../common');
+
+const expectedDeprecationWarning = 'Unhandled promise rejections are ' +
+                                   'deprecated. In the future, promise ' +
+                                   'rejections that are not handled will ' +
+                                   'terminate the Node.js process with a ' +
+                                   'non-zero exit code.';
+const expectedPromiseWarning = 'Unhandled promise rejection (rejection id: ' +
+                               '1): Symbol()';
+
+common.expectWarning({
+  DeprecationWarning: expectedDeprecationWarning,
+  UnhandledPromiseRejectionWarning: expectedPromiseWarning,
+});
+
+// ensure this doesn't crash
+Promise.reject(Symbol());