Fix for stack traces appearing twice in node v6 - issue #389

.travis.yml

@@ -1,6 +1,7 @@
 language: node_js
 sudo: false
 node_js:
+  - "6"
   - "5"
   - "4"
   - "0.12"

lib/layouts.js

@@ -3,6 +3,7 @@ var dateFormat = require('./date_format')
 , os = require('os')
 , eol = os.EOL || '\n'
 , util = require('util')
+, semver = require('semver')
 , replacementRegExp = /%[sdj]/g
 , layoutMakers = {
   "messagePassThrough": function() { return messagePassThroughLayout; },
@@ -28,7 +29,13 @@ var dateFormat = require('./date_format')
 function wrapErrorsWithInspect(items) {
   return items.map(function(item) {
     if ((item instanceof Error) && item.stack) {
-      return { inspect: function() { return util.format(item) + '\n' + item.stack; } };
+      return { inspect: function() {
+        if (semver.satisfies(process.version, '>=6')) {
+          return util.format(item);
+        } else {
+          return util.format(item) + '\n' + item.stack;           
+        }
+      } };
     } else {
       return item;
     }

test/layouts-test.js

@@ -2,6 +2,7 @@
 var vows = require('vows')
 , assert = require('assert')
 , os =  require('os')
+, semver = require('semver')
 , EOL = os.EOL || '\n';
 
 //used for patternLayout tests.
@@ -108,7 +109,7 @@ vows.describe('log4js layouts').addBatch({
         });
       },
       'should print error the contained error message': function(layoutOutput) {
-        var m = layoutOutput.match(/\{ \[Error: My Unique Error Message\]/);
+        var m = layoutOutput.match(/Error: My Unique Error Message/);
         assert.isArray(m);
       },
       'should print error augmented string attributes': function(layoutOutput) {
@@ -142,7 +143,7 @@ vows.describe('log4js layouts').addBatch({
       assert.equal(layout(event), "[2010-12-05 14:18:30.045] [DEBUG] tests - this is a test");
     },
     'should output a stacktrace, message if the event has an error attached': function(args) {
-      var layout = args[0], event = args[1], output, lines,
+      var i, layout = args[0], event = args[1], output, lines,
       error = new Error("Some made-up error"),
       stack = error.stack.split(/\n/);
 
@@ -150,15 +151,26 @@ vows.describe('log4js layouts').addBatch({
       output = layout(event);
       lines = output.split(/\n/);
 
-      assert.equal(lines.length - 1, stack.length);
-      assert.equal(
-        lines[0],
-        "[2010-12-05 14:18:30.045] [DEBUG] tests - this is a test [Error: Some made-up error]"
-      );
-
-      for (var i = 1; i < stack.length; i++) {
-        assert.equal(lines[i+2], stack[i+1]);
+      if (semver.satisfies(process.version, '>=6')) {
+        assert.equal(lines.length, stack.length);
+        assert.equal(
+          lines[0],
+          "[2010-12-05 14:18:30.045] [DEBUG] tests - this is a test Error: Some made-up error"
+        );
+        for (i = 1; i < stack.length; i++) {
+          assert.equal(lines[i], stack[i]);
+        }
+      } else {
+        assert.equal(lines.length - 1, stack.length);
+        assert.equal(
+          lines[0],
+          "[2010-12-05 14:18:30.045] [DEBUG] tests - this is a test [Error: Some made-up error]"
+        );
+        for (i = 1; i < stack.length; i++) {
+          assert.equal(lines[i+2], stack[i+1]);
+        }
       }
+
     },
     'should output any extra data in the log event as util.inspect strings': function(args) {
       var layout = args[0], event = args[1], output, lines;