[api test] Added .tag() reactor for setting tags based on values ca…

…lculated from other reactors.
nodejitsu · Mar 11, 2013 · b84a118 · b84a118
1 parent 74555a8
commit b84a118
Show file tree

Hide file tree

Showing 2 changed files with 108 additions and 0 deletions.
diff --git a/lib/godot/reactor/tag.js b/lib/godot/reactor/tag.js
@@ -0,0 +1,50 @@
+/*
+ * tag.js: Stream for setting the value (and any tags) from a second reactor on any data received.
+ *
+ * (C) 2013, Nodejitsu Inc.
+ *
+ */
+
+var util = require('util'),
+    ReadWriteStream = require('../common/read-write-stream'),
+    Reactor = require('./reactor');
+
+//
+// ### function Tag (tag, reactor)
+// #### @tag {string} Tag to use for the value of `reactor`.
+// #### @reactor {godot.reactor().type()} Reactor to be created
+// Constructor function for the tag stream responsible for setting
+// the value (and any tags) from a second reactor on any data received.
+//
+var Tag = module.exports = function (tag, reactor) {
+  ReadWriteStream.call(this);
+
+  var self = this;
+
+  this.tag     = tag;
+  this.stream  = new ReadWriteStream();
+  this.reactor = reactor.createStream(this.stream);
+  this.reactor.on('data', function (data) {
+    data.tags.push(self.tag + ':' + data.metric)
+    data.metric = data._metric;
+    data.tags = data.tags || [];
+    delete data._metric;
+    self.emit('data', data);
+  });
+};
+
+//
+// Inherit from ReadWriteStream
+//
+util.inherits(Tag, ReadWriteStream);
+
+//
+// ### function write (data)
+// Writes the `data` to the tag stream associated
+// with this instance and sets `_metric` so it can
+// be replaced later on.
+//
+Tag.prototype.write = function (data) {
+  data._metric = data.metric;
+  this.stream.write(data);
+};
diff --git a/test/reactor/tag-test.js b/test/reactor/tag-test.js
@@ -0,0 +1,58 @@
+/*
+ * tag-test.js: Tests for the Tag reactor stream.
+ *
+ * (C) 2012, Nodejitsu Inc.
+ *
+ */
+
+var assert = require('assert'),
+    vows = require('vows'),
+    range = require('r...e'),
+    windowStream = require('window-stream'),
+    godot = require('../../lib/godot'),
+    helpers = require('../helpers'),
+    macros = require('../macros').reactor;
+
+var M1_ALPHA = 1 - Math.exp(-5/60);
+
+vows.describe('godot/reactor/tag').addBatch({
+  "Godot tag": {
+    "with a simple movingAverage": macros.shouldEmitDataSync(
+      godot
+        .reactor()
+        .tag('avg', godot.reactor().movingAverage({
+          average: 'simple',
+          window: new windowStream.EventWindow({ size: 10 })
+        })),
+      helpers.timeSeries({
+        metric: function (num) {
+          return num;
+        }
+      }, 1000, 10),
+      100,
+      function (all) {
+        all.forEach(function (data, i) {
+          var num = data.metric,
+              di  = i + 1,
+              avg, set;
+
+          set = di < 10
+            ? range(1, di)
+            : range(di - 9, di);
+
+          avg = data.tags.filter(function (tag) {
+            return tag.indexOf('avg') !== -1
+          })[0];
+
+          assert.equal(num, di);
+          assert.isString(avg);
+
+          avg = parseFloat(avg.split(':')[1], 10);
+          assert.equal(avg, godot.math.mean(set.toArray().map(function (n) {
+            return { metric: n };
+          })));
+        });
+      }
+    )
+  }
+}).export(module);