Fixing variable naming bugs in TokenBucket, adding basic unit tests f…

…or TokenBucket

.gitignore

@@ -0,0 +1,4 @@
+build
+.lock-wscript
+.DS_Store
+node_modules

lib/tokenBucket.js

@@ -56,8 +56,10 @@ TokenBucket.prototype = {
    *  false.
    */
   removeTokens: function(count, callback) {
+    var self = this;
+
     // Is this an infinite size bucket?
-    if (!this.maxBurst) {
+    if (!this.bucketSize) {
       callback(null, count, Number.POSITIVE_INFINITY);
       return true;
     }
@@ -77,15 +79,13 @@ TokenBucket.prototype = {
       // How long do we need to wait to make up the difference in tokens?
       var waitInterval = Math.ceil(
         (count - this.content) * (this.interval / this.tokensPerInterval));
-      setTimeout(function() { removeTokens(count, callback); }, waitInterval);
+      setTimeout(function() { self.removeTokens(count, callback); }, waitInterval);
       return false;
     }
 
-    if (parent) {
-      var self = this;
-
+    if (this.parentBucket) {
       // Remove the requested from the parent bucket first
-      return parent.removeTokens(count, function(err, remainingTokens) {
+      return this.parentBucket.removeTokens(count, function(err, remainingTokens) {
         if (err) {
           callback(err, null);
           return;
@@ -101,7 +101,7 @@ TokenBucket.prototype = {
     } else {
       // Remove the requested tokens from this bucket and fire the callback
       this.content -= count;
-      callback(null, self.content);
+      callback(null, this.content);
       return true;
     }
   },
@@ -121,7 +121,7 @@ TokenBucket.prototype = {
     this.lastDrip = now;
 
     var dripAmount = deltaMS * (this.tokensPerInterval / this.interval);
-    this.content = Math.min(this.content + dripAmount, maxBurst);
+    this.content = Math.min(this.content + dripAmount, this.bucketSize);
   }
 };
 

package.json

@@ -4,7 +4,10 @@
   "version": "0.0.2",
   "author": "John Hurliman <jhurliman@cull.tv>",
   "dependencies": { },
-  "devDependencies": { },
+  "devDependencies": {
+    "assert": "0.4.9",
+    "vows": "0.6.3"
+  },
   "keywords": ["rate", "limiting", "throttling"],
   "repository": "git://github.com/jhurliman/node-rate-limiter",
   "bugs": { "url": "http://github.com/jhurliman/node-rate-limiter/issues" },

tests/tokenbucket-tests.js

@@ -0,0 +1,70 @@
+var vows = require('vows');
+var assert = require('assert');
+
+var TIMING_EPSILON = 10;
+
+var TokenBucket = require('../lib/tokenBucket');
+var gBucket;
+var gStart;
+
+vows.describe('TokenBucket').addBatch({
+  'capacity 10, 1 per 100ms': {
+    topic: new TokenBucket(10, 1, 100),
+
+    'is initialized empty': function(bucket) {
+      gBucket = bucket;
+      assert.equal(bucket.bucketSize, 10);
+      assert.equal(bucket.tokensPerInterval, 1);
+      assert.equal(bucket.content, 0);
+    },
+    'removing 10 tokens': {
+      topic: function(bucket) {
+        gStart = +new Date();
+        bucket.removeTokens(10, this.callback);
+      },
+      'takes 1 second': function(remainingTokens) {
+        var duration = +new Date() - gStart;
+        var diff = Math.abs(1000 - duration);
+        assert.ok(diff < TIMING_EPSILON, diff+'');
+        assert.equal(remainingTokens, 0);
+      },
+      'and removing another 10 tokens': {
+        topic: function() {
+          gStart = +new Date();
+          assert.equal(gBucket.content, 0);
+          gBucket.removeTokens(10, this.callback);
+        },
+        'takes 1 second': function() {
+          var duration = +new Date() - gStart;
+          var diff = Math.abs(1000 - duration);
+          assert.ok(diff < TIMING_EPSILON, diff+'');
+        }
+      },
+      'and waiting 2 seconds': {
+        topic: function() {
+          var self = this;
+          setTimeout(function() {
+            gStart = +new Date();
+            gBucket.removeTokens(10, self.callback);
+          }, 2000);
+        },
+        'gives us only 10 tokens': function(remainingTokens) {
+          var duration = +new Date() - gStart;
+          assert.ok(duration < TIMING_EPSILON, duration+'');
+          assert.equal(remainingTokens, 0);
+        },
+        'and removing 1 token': {
+          topic: function() {
+            gStart = +new Date();
+            gBucket.removeTokens(1, this.callback);
+          },
+          'takes 100ms': function() {
+            var duration = +new Date() - gStart;
+            var diff = Math.abs(100 - duration);
+            assert.ok(diff < TIMING_EPSILON, diff+'');
+          }
+        }
+      }
+    }
+  },
+}).export(module);