util: Fix inspection for Error

Fixes #1634.

1 files changed, 26 insertions, 2 deletions

diff --git a/lib/util.js b/lib/util.js
index 84833d38c4..5e4f1a67a2 100644
--- a/lib/util.js
+++ b/lib/util.js
@@ -185,6 +185,9 @@ function formatValue(ctx, value, recurseTimes) {
     if (isDate(value)) {
       return ctx.stylize(value.toUTCString(), 'date');
     }
+    if (isError(value)) {
+      return formatError(value);
+    }
   }
 
   var base = '', array = false, braces = ['{', '}'];
@@ -211,6 +214,11 @@ function formatValue(ctx, value, recurseTimes) {
     base = ' ' + value.toUTCString();
   }
 
+  // Make error with message first say the error
+  if (isError(value)) {
+    base = ' ' + formatError(value);
+  }
+
   if (keys.length === 0 && (!array || value.length == 0)) {
     return braces[0] + base + braces[1];
   }
@@ -264,6 +272,11 @@ function formatPrimitive(ctx, value) {
 }
 
 
+function formatError(value) {
+  return '[' + Error.prototype.toString.call(value) + ']';
+}
+
+
 function formatArray(ctx, value, recurseTimes, visibleKeys, keys) {
   var output = [];
   for (var i = 0, l = value.length; i < l; ++i) {
@@ -374,13 +387,24 @@ function isArray(ar) {
 
 function isRegExp(re) {
   return re instanceof RegExp ||
-    (typeof re === 'object' && Object.prototype.toString.call(re) === '[object RegExp]');
+    (typeof re === 'object' && objectToString(re) === '[object RegExp]');
 }
 
 
 function isDate(d) {
   return d instanceof Date ||
-    (typeof d === 'object' && Object.prototype.toString.call(d) === '[object Date]');
+    (typeof d === 'object' && objectToString(d) === '[object Date]');
+}
+
+
+function isError(e) {
+  return e instanceof Error ||
+    (typeof e === 'object' && objectToString(e) === '[object Error]');
+}
+
+
+function objectToString(o) {
+  return Object.prototype.toString.call(o);
 }