Fixed the timer test to output on a timer basis as it suggests

Added a random duration to give a clear picture of what the timer actually does

tests/timer.js

@@ -2,26 +2,39 @@ var Timer = require('../metrics/timer');
 
 var test = function(callback){
   console.log("\nCreating a new timer, updating 10 times / sec for 30 secs");
-  var timer = new Timer();
+  var timer = new Timer()
+      , n = 0;
+
+  var updateInterval = setInterval(function(){
+    //simulates the duration that a task takes between 0 and 500 milliseconds
+    //And then update the timer for the duration of that time
+    var duration = Math.round(Math.random() * (500));
+    timer.update(duration);
+    n += 1;
+    if (n % 10 == 0) {
+      process.stdout.write(".")
+    }
+  }, 100);
+
+  setTimeout(function(){
+    clearInterval(updateInterval);
+    console.log('Expected rate: 10/sec');
+    console.log('count: ' + timer.count());
+    console.log('min: ' + timer.min());
+    console.log('max: ' + timer.max());
+    console.log('mean: ' + timer.mean());
+    console.log('stdDev: ' + timer.stdDev());
+    console.log('percentiles: ' + JSON.stringify(timer.percentiles(), undefined, 2));
+    console.log('oneMinuteRate: ' + timer.oneMinuteRate());
+    console.log('fiveMinuteRate: ' + timer.fiveMinuteRate());
+    console.log('fifteeenMinuteRate: ' + timer.fifteenMinuteRate());
+    console.log('meanRate: ' + timer.meanRate());
+  }, 30000);
 
-  for(var i = 0; i < 10000; i++) {
-    timer.update(i);
-  }
-  timer.tick();
-  console.log(timer.count());
-  console.log(timer.min());
-  console.log(timer.max());
-  console.log(timer.mean());
-  console.log(timer.stdDev());
-  console.log(timer.percentiles());
-  console.log(timer.oneMinuteRate());
-  console.log(timer.fiveMinuteRate());
-  console.log(timer.fifteenMinuteRate());
-  console.log(timer.meanRate());
   if (typeof callback == 'function') {
     callback();
   }
-}
+};
 
 if (module.parent) {
   module.exports = test;