From 3741f0516d9eb1364b92b7d372a9d7e93d5700af Mon Sep 17 00:00:00 2001
From: laconbass <lorenzogrv@gmail.com>
Date: Wed, 15 Jan 2014 18:49:16 +0100
Subject: [PATCH] Avoid error instantiation if possible on assert.throws

Given an error constructor as function, try to get the error name from
its prototype or itself before relying on the old behaviour.

Closes #220

Replaces [the old pull](https://github.com/chaijs/chai/pull/221) to avoid
useless commits.
---
 lib/chai/core/assertions.js | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/lib/chai/core/assertions.js b/lib/chai/core/assertions.js
index d08a4205c..d41a48c1c 100644
--- a/lib/chai/core/assertions.js
+++ b/lib/chai/core/assertions.js
@@ -1026,7 +1026,10 @@ module.exports = function (chai, _) {
       constructor = null;
       errMsg = null;
     } else if (typeof constructor === 'function') {
-      name = (new constructor()).name;
+      name = constructor.prototype.name || constructor.name;
+      if (name === 'Error' && constructor !== Error) {
+        name = (new constructor()).name;
+      }
     } else {
       constructor = null;
     }