From c53db1e8e9bb65779d791046daa39ed88c8f1045 Mon Sep 17 00:00:00 2001
From: Ruslan Bekenev <furyinbox@gmail.com>
Date: Sun, 2 Apr 2017 20:11:42 +0300
Subject: [PATCH] assert: show thrown message in doesNotThrow()

assert.doesNotThrow() should show actual error message instead
of "Got unwanted exception" which is not really helpful.

PR-URL: https://github.com/nodejs/node/pull/12167
Reviewed-By: Anna Henningsen <anna@addaleax.net>
Reviewed-By: Yuta Hiroto <hello@about-hiroppy.com>
Reviewed-By: James M Snell <jasnell@gmail.com>
Reviewed-By: Joyee Cheung <joyeec9h3@gmail.com>
Reviewed-By: Refael Ackermann <refack@gmail.com>
---
 lib/assert.js                |  5 ++++-
 test/parallel/test-assert.js | 28 ++++++++++++++++++++++++++++
 2 files changed, 32 insertions(+), 1 deletion(-)

diff --git a/lib/assert.js b/lib/assert.js
index b66061b29b0614..a948028501adfc 100644
--- a/lib/assert.js
+++ b/lib/assert.js
@@ -546,7 +546,10 @@ function innerThrows(shouldThrow, block, expected, message) {
   } else if (actual !== undefined) {
     if (!expected || expectedException(actual, expected)) {
       details = message ? `: ${message}` : '.';
-      fail(actual, expected, `Got unwanted exception${details}`, fail);
+      fail(actual,
+           expected,
+           `Got unwanted exception${details}\n${actual.message}`,
+           fail);
     }
     throw actual;
   }
diff --git a/test/parallel/test-assert.js b/test/parallel/test-assert.js
index d4a1b277bcc195..348927cd5c6a1b 100644
--- a/test/parallel/test-assert.js
+++ b/test/parallel/test-assert.js
@@ -468,6 +468,34 @@ assert.throws(() => {
 }, /Got unwanted exception: user message/,
               'a.doesNotThrow ignores user message');
 
+{
+  let threw = false;
+  try {
+    assert.doesNotThrow(makeBlock(thrower, Error), 'user message');
+  } catch (e) {
+    threw = true;
+    common.expectsError({
+      code: 'ERR_ASSERTION',
+      message: /Got unwanted exception: user message\n\[object Object\]/
+    })(e);
+  }
+  assert.ok(threw);
+}
+
+{
+  let threw = false;
+  try {
+    assert.doesNotThrow(makeBlock(thrower, Error));
+  } catch (e) {
+    threw = true;
+    common.expectsError({
+      code: 'ERR_ASSERTION',
+      message: /Got unwanted exception\.\n\[object Object\]/
+    })(e);
+  }
+  assert.ok(threw);
+}
+
 // make sure that validating using constructor really works
 {
   let threw = false;