add custom date logger

Readme.md

@@ -25,6 +25,14 @@ Specifying a specific stream:
       , Log = require('log')
       , log = new Log(Log.DEBUG, fs.createWriteStream('my.log'));
 
+Specifying a specific date logging (in epoch milliseconds):
+    var Log = require('log')
+      , log = new Log(Log.DEBUG, process.stdout, { write: function(date) {
+        return Date.getTime();
+      }, read: function(s) {
+        return new Date(parseInt(s, 10));
+      }});  
+
 Instead of the log level constants, you may also supply a string:
 
     var Log = require('log')

lib/log.js

@@ -20,10 +20,18 @@ var EventEmitter = require('events').EventEmitter;
  * @api public
  */
 
-var Log = exports = module.exports = function Log(level, stream){
+var Log = exports = module.exports = function Log(level, stream, date){
   if ('string' == typeof level) level = exports[level.toUpperCase()];
   this.level = level || exports.DEBUG;
   this.stream = stream || process.stdout;
+  this.date = date || {
+    write: function(d) {
+      return d.toUTCString();
+    },
+    read: function(s) {
+      return new Date(s);
+    }
+  };
   if (this.stream.readable) this.read();
 };
 
@@ -117,7 +125,7 @@ Log.prototype = {
         try {
           var captures = line.match(/^\[([^\]]+)\] (\w+) (.*)/);
           var obj = {
-              date: new Date(captures[1])
+              date: self.date.read(captures[1])
             , level: exports[captures[2]]
             , levelString: captures[2]
             , msg: captures[3] 
@@ -146,7 +154,7 @@ Log.prototype = {
   log: function(levelStr, msg) {
     if (exports[levelStr] <= this.level) {
       this.stream.write(
-          '[' + new Date().toUTCString() + ']'
+          '[' + this.date.write(new Date()) + ']'
         + ' ' + levelStr
         + ' ' + msg
         + '\n'

test/test.js

@@ -0,0 +1,67 @@
+var assert = require('assert'),
+fs = require('fs'),
+Log = require('../lib/log'),
+Stream = require('stream').Stream,
+util = require('util');
+
+var WriteStream = function() {
+  this.data = '';
+};
+util.inherits(WriteStream, Stream);
+WriteStream.prototype.write = function(data) {
+  this.data += data;
+};
+
+var ReadStream = function(data) {
+  var self = this;
+  self.readable = true;
+  process.nextTick(function() {
+    data.split('').forEach(function(c) {
+      self.emit('data', c);
+    });
+    self.emit('end');
+  });
+};
+util.inherits(ReadStream, Stream);
+ReadStream.prototype.setEncoding = function() {
+};
+
+module.exports = {
+  'test default date format ': function(beforeExit) {
+    var write_stream = new WriteStream(),
+    write_log = new Log(Log.DEBUG, write_stream);
+    write_log.notice('foo');
+
+    var read_stream = new ReadStream(write_stream.data),
+    read_log = new Log('debug', read_stream),
+    lines = [];
+
+    read_log.on('line', function(line){
+      lines.push(line);
+    });
+    
+    beforeExit(function() {
+      assert.equal(1, lines.length);
+      assert.equal(true, lines[0].date.getTime() > 0);
+    });
+  },
+  'test custom date format': function(beforeExit) {
+    var write_stream = new WriteStream(),
+    custom_date = { write: function(d) { return 42; }, read: function(s) { return new Date(parseInt(s, 10)); } },
+    write_log = new Log(Log.DEBUG, write_stream, custom_date);
+    write_log.notice('foo');
+
+    var read_stream = new ReadStream(write_stream.data),
+    read_log = new Log('debug', read_stream, custom_date),
+    lines = [];
+    read_log.on('line', function(line){
+      lines.push(line);
+    });
+
+    beforeExit(function() {
+      assert.equal(1, lines.length);
+      assert.equal(42, lines[0].date.getTime());
+    });
+  }
+};  
+