Baconize RequestCounter

Author: sheac

package.json

@@ -30,6 +30,7 @@
   },
   "dependencies": {
     "async": "^0.9.0",
+    "baconjs": "^0.7.22",
     "body-parser": "^1.8.2",
     "express": "^4.9.3",
     "grunt-env": "^0.4.1",

src/controllers/request-counter.js

@@ -1,20 +1,17 @@
 module.exports = RequestCounter;
 
+var Bacon = require('baconjs'),
+    _ = require('lodash');
+
 var redis = require('../resources/redis'),
     ApiResponder = require('../resources/api-responder');
 
 var NUM_REQS_KEY = 'NUM_REQS';
 
 RequestCounter.get = function(req, res) {
-    redis.incr(NUM_REQS_KEY, function(err, newVal) {
-        var apiResponder = new ApiResponder(res);
-        if (err) {
-            apiResponder.sendError(err);
-        } else {
-            var data = { num_reqs: newVal };
-            apiResponder.sendSuccess(data);
-        }
-    });
+    var newNum = Bacon.fromNodeCallback(_.bind(redis.incr, redis), NUM_REQS_KEY).toProperty(),
+        data = Bacon.combineTemplate({ num_reqs: newNum });
+    ApiResponder.respond(res, data);
 };
 
 function RequestCounter() {}

src/resources/api-responder.js

@@ -2,14 +2,10 @@ module.exports = ApiResponder;
 
 var _ = require('lodash');
 
-function ApiResponder(res) {
-    this.res = res;
-    this.sendSuccess = function(data) {
-        this.res.status(200).send(data);
-    };
-
-    this.sendError = function(err) {
-        this.res.status(500).send(err);
-    };
-}
+function ApiResponder() {}
+
+ApiResponder.respond = function(res, stream, redCode) {
+    stream.onValue(_.bind(res.send, res.status(typeof retCode === 'number' ? retCode : 200)));
+    stream.onError(_.bind(res.send, res.status(500)));
+};
 

test/request-counter.js

@@ -17,15 +17,16 @@ after(function(done) {
 it('should count the number of requests sent', function(done) {
     var url = 'http://' + config.ip + ':' + config.port + '/requestcounter';
 
-    async.times(5, function(n, next) {
+    var numReqs = Math.ceil(Math.random() * 20),
+        expected = 1;
+    async.times(numReqs, function(reqIndex, next) {
         request(url, function(err, resp, body) {
             if (err) next(err);
 
             try {
                 body = JSON.parse(body);
-                var found = parseInt(body.num_reqs),
-                    expected = n + 1;
-                found.should.equal(expected);
+                parseInt(body.num_reqs).should.equal(expected);
+                expected += 1;
                 next();
             } catch(e) {
                 next(e);