Changed layouts to use util.format instead of my own implementation

lib/layouts.js

@@ -24,37 +24,19 @@ var dateFormat = require('./date_format')
     , OFF: "grey"
   };
 
-function formatLogData(logData) {
-    var output = ""
-      , data = Array.isArray(logData) ? logData.slice() : Array.prototype.slice.call(arguments)
-      , format = data.shift();
-
-    if (typeof format  === "string") {
-        output = format.replace(replacementRegExp, function(match) {
-            switch (match) {
-            case "%s": return new String(data.shift());
-            case "%d": return new Number(data.shift());
-            case "%j": return JSON.stringify(data.shift());
-            default:
-                return match;
-            };
-        });
+function wrapErrorsWithInspect(items) {
+  return items.map(function(item) {
+    if ((item instanceof Error) && item.stack) {
+      return { inspect: function() { return util.format(item) + '\n' + item.stack; } };
     } else {
-        //put it back, it's not a format string
-        data.unshift(format);
+      return item;
     }
+  });
+}
 
-    data.forEach(function (item) {
-        if (output) {
-            output += ' ';
-        }
-        output += util.inspect(item);
-        if (item && item.stack) {
-            output += "\n" + item.stack;
-        }
-    });
-
-    return output;
+function formatLogData(logData) {
+  var data = Array.isArray(logData) ? logData : Array.prototype.slice.call(arguments);
+  return util.format.apply(util, wrapErrorsWithInspect(data));
 }
 
 var styles = {

test/layouts-test.js

@@ -64,7 +64,7 @@ vows.describe('log4js layouts').addBatch({
                     colour: "green"
                   , toString: function() { return "ERROR"; }
                 }
-              }), "thing 1 'cheese'");
+              }), "thing 1 cheese");
           },
         'should output the first item even if it is not a string': function(layout) {
             assert.equal(layout({
@@ -89,21 +89,20 @@ vows.describe('log4js layouts').addBatch({
             }).match(/Error\s+at Object\..*\s+\((.*)test[\\\/]layouts-test\.js\:\d+\:\d+\)\s+at runTest/)
             , 'regexp did not return a match');
         },
-        'with passed augmented errors':
-        { topic:
-          function(layout){
-              var e = new Error("My Unique Error Message");
-              e.augmented = "My Unique attribute value"
-              e.augObj = { at1: "at2" }
-              return layout({
-                  data: [ e ]
-                , startTime: new Date(2010, 11, 5, 14, 18, 30, 45)
-                , categoryName: "cheese"
-                , level: {
-                    colour: "green"
-                  , toString: function() { return "ERROR"; }
-                }
-              });
+        'with passed augmented errors': { 
+          topic: function(layout){
+            var e = new Error("My Unique Error Message");
+            e.augmented = "My Unique attribute value"
+            e.augObj = { at1: "at2" }
+            return layout({
+              data: [ e ]
+              , startTime: new Date(2010, 11, 5, 14, 18, 30, 45)
+              , categoryName: "cheese"
+              , level: {
+                colour: "green"
+                , toString: function() { return "ERROR"; }
+              }
+            });
           },
           'should print error the contained error message': function(layoutOutput) {
               var m = layoutOutput.match(/\{ \[Error: My Unique Error Message\]/);