Extract buffer key generation logic and add some more tests

Author: dbader

lib/aggregators.js

@@ -8,12 +8,13 @@ function Aggregator(opts) {
     this.buffer = {};
 }
 
-Aggregator.prototype.addPoint = function(Type, key, value, tags, host) {
-    var bufferKey = key;
-    if (tags) {
-        bufferKey += tags.concat().sort().join();
-    }
+Aggregator.prototype.makeBufferKey = function(key, tags) {
+    tags = tags || [''];
+    return key + '#' + tags.concat().sort().join('.');
+};
 
+Aggregator.prototype.addPoint = function(Type, key, value, tags, host) {
+    var bufferKey = this.makeBufferKey(key, tags);
     if (!this.buffer.hasOwnProperty(bufferKey)) {
         this.buffer[bufferKey] = new Type(key, tags, host);
     }

test/aggregators_tests.js

@@ -54,5 +54,24 @@ describe('Aggregator', function() {
         f[0].should.have.deep.property('points[0][1]', 2);
         f[1].should.have.deep.property('points[0][1]', 3);
     });
+
+    it('should treat all empty tags definitions the same', function() {
+        var agg = new aggregators.Aggregator();
+        agg.addPoint(metrics.Gauge, 'noTagsKey', 1, null, 'myhost');
+        agg.addPoint(metrics.Gauge, 'noTagsKey', 2, undefined, 'myhost');
+        agg.addPoint(metrics.Gauge, 'noTagsKey', 3, [], 'myhost');
+        var f = agg.flush();
+        f.should.have.length(1);
+        f[0].should.have.deep.property('points[0][1]', 3);
+    });
+
+    it('should normalize the tag order', function() {
+        var agg = new aggregators.Aggregator();
+        agg.addPoint(metrics.Gauge, 'mykey', 1, ['t1', 't2', 't3'], 'myhost');
+        agg.addPoint(metrics.Gauge, 'mykey', 2, ['t3', 't2', 't1'], 'myhost');
+        var f = agg.flush();
+        f.should.have.length(1);
+        f[0].should.have.deep.property('points[0][1]', 2);
+    });
 });