process: improve unhandled rejection message

PR-URL: https://github.com/nodejs/node/pull/17158
Refs: https://github.com/nodejs/node/pull/16768
Reviewed-By: Refael Ackermann <refack@gmail.com>
Reviewed-By: Benjamin Gruenbaum <benjamingr@gmail.com>
Reviewed-By: Evan Lucas <evanlucas@me.com>
Reviewed-By: James M Snell <jasnell@gmail.com>

1 files changed, 31 insertions, 6 deletions

diff --git a/test/parallel/test-promises-warning-on-unhandled-rejection.js b/test/parallel/test-promises-warning-on-unhandled-rejection.js
index 10f95162a0..3ac7d8698b 100644
--- a/test/parallel/test-promises-warning-on-unhandled-rejection.js
+++ b/test/parallel/test-promises-warning-on-unhandled-rejection.js
@@ -12,18 +12,43 @@ let b = 0;
 process.on('warning', common.mustCall((warning) => {
   switch (b++) {
     case 0:
-      assert.strictEqual(warning.name, 'UnhandledPromiseRejectionWarning');
-      assert(/Unhandled promise rejection/.test(warning.message));
+      // String rejection error displayed
+      assert.strictEqual(warning.message, 'This was rejected');
       break;
     case 1:
-      assert.strictEqual(warning.name, 'DeprecationWarning');
+      // Warning about rejection not being handled (will be next tick)
+      assert.strictEqual(warning.name, 'UnhandledPromiseRejectionWarning');
+      assert(
+        /Unhandled promise rejection/.test(warning.message),
+        'Expected warning message to contain "Unhandled promise rejection" ' +
+        'but did not. Had "' + warning.message + '" instead.'
+      );
       break;
     case 2:
+      // One time deprecation warning, first unhandled rejection
+      assert.strictEqual(warning.name, 'DeprecationWarning');
+      break;
+    case 3:
+      // Number rejection error displayed. Note it's been stringified
+      assert.strictEqual(warning.message, '42');
+      break;
+    case 4:
+      // Unhandled rejection warning (won't be handled next tick)
+      assert.strictEqual(warning.name, 'UnhandledPromiseRejectionWarning');
+      assert(
+        /Unhandled promise rejection/.test(warning.message),
+        'Expected warning message to contain "Unhandled promise rejection" ' +
+        'but did not. Had "' + warning.message + '" instead.'
+      );
+      break;
+    case 5:
+      // Rejection handled asynchronously.
       assert.strictEqual(warning.name, 'PromiseRejectionHandledWarning');
       assert(/Promise rejection was handled asynchronously/
         .test(warning.message));
   }
-}, 3));
+}, 6));
 
-const p = Promise.reject('This was rejected');
-setImmediate(common.mustCall(() => p.catch(() => {})));
+const p = Promise.reject('This was rejected'); // Reject with a string
+setImmediate(common.mustCall(() => p.catch(() => { })));
+Promise.reject(42); // Reject with a number