added performance profiling support

.jshintrc

@@ -35,7 +35,7 @@
     "maxlen": 120,
 
     // Require capitalized names for constructor functions.
-    "newcap": true,
+    "newcap": false,
 
     // Enforce use of single quotation marks for strings.
     "quotmark": "single",

CHANGELOG.md

@@ -1,3 +1,7 @@
+## 1.3.0 (April 30, 2015)
+
+* added Performance profiling
+
 ## 1.2.0 (April 25, 2015)
 
 * Generate semantic html by injecting script tag before end of html tag

README.md

@@ -19,6 +19,7 @@
     // create the view engine with `react-engine`
     var engine = require('react-engine').server.create({
       reactRoutes: <string> /* pass in the path to react-router routes optionally */
+      performanceCollector: <function> /* optional function to collect perf stats */
     });
 
     // set the engine
@@ -50,7 +51,8 @@
             "renderer": {
               "method": "create",
                 "arguments": [{
-                    "reactRoutes": "path:<PATH_TO_REACT-ROUTER_ROUTES>"
+                    "reactRoutes": "path:<PATH_TO_REACT-ROUTER_ROUTES>",
+                    "performanceCollector": "require:<PATH_TO_PERF_COLLECTOR_FUNCTION>"
                 }]
             }
         }
@@ -100,6 +102,32 @@ document.addEventListener('DOMContentLoaded', function onLoad() {
 };
 ```
 
+### Performance Profiling
+
+Pass in a function to the `performanceCollector` property to collect the `stats` 
+object for every render.
+
+##### `stats`
+The object that contains the stats info for each render by react-engine.
+It has the below properties.
+- `name` - Name of the template or the url in case of react router rendering.
+- `startTime` - The start time of render.
+- `endTime` - The completion time of render.
+- `duration` - The duration taken to render (in milliseconds).
+
+```js
+// example
+function collector(stats) {
+  console.log(stats);
+}
+
+var engine = require('react-engine').server.create({
+  reactRoutes: './routes.jsx'
+  performanceCollector: collector
+});
+```
+
+
 ### Notes
 * On the client side, the state is exposed on the window object's property `__REACT_ENGINE__`
 * In development mode, views are automatically reloaded before render. So there is no need to restart the server for seeing the changes.

lib/performance.js

@@ -0,0 +1,37 @@
+/*-------------------------------------------------------------------------------------------------------------------*\
+|  Copyright (C) 2015 PayPal                                                                                          |
+|                                                                                                                     |
+|  Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance     |
+|  with the License.                                                                                                  |
+|                                                                                                                     |
+|  You may obtain a copy of the License at                                                                            |
+|                                                                                                                     |
+|       http://www.apache.org/licenses/LICENSE-2.0                                                                    |
+|                                                                                                                     |
+|  Unless required by applicable law or agreed to in writing, software distributed under the License is distributed   |
+|  on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for  |
+|  the specific language governing permissions and limitations under the License.                                     |
+\*-------------------------------------------------------------------------------------------------------------------*/
+
+'use strict';
+
+module.exports = function Performance(name) {
+
+  var startTime = Date.now();
+  var time = process.hrtime();
+
+  return function end() {
+
+    var diff = process.hrtime(time);
+
+    // duration in milliseconds
+    var duration = diff[0] + (diff[1] / 1000000);
+
+    return {
+      name: name,
+      startTime: startTime,
+      endTime: Date.now(),
+      duration: duration
+    };
+  };
+};

lib/server.js

@@ -16,8 +16,10 @@
 'use strict';
 
 var util = require('./util');
+var assert = require('assert');
 var Config = require('./config');
 var format = require('util').format;
+var Performance = require('./performance');
 var omit = require('lodash-node/compat/object/omit');
 var merge = require('lodash-node/compat/object/merge');
 
@@ -36,10 +38,21 @@ exports.create = function create(createOptions) {
 
   createOptions = createOptions || {};
 
+  if (createOptions.performanceCollector) {
+    assert.equal(typeof createOptions.performanceCollector,
+        'function',
+        '`performanceCollector` - should be a function');
+  }
+
   // the render implementation
   return function render(thing, options, callback) {
 
     var routes;
+    var perfInstance;
+
+    if (createOptions.performanceCollector) {
+      perfInstance = Performance(thing);
+    }
 
     function done(err, html) {
       if (options.settings.env === 'development') {
@@ -49,6 +62,10 @@ exports.create = function create(createOptions) {
         util.clearRequireCacheInDir(options.settings.views, options.settings['view engine']);
       }
 
+      if (createOptions.performanceCollector) {
+        createOptions.performanceCollector(perfInstance());
+      }
+
       callback(err, html);
     }
 

package.json

@@ -1,6 +1,6 @@
 {
   "name": "react-engine",
-  "version": "1.2.0",
+  "version": "1.3.0",
   "description": "a composite render engine for express apps to render both plain react views and react-router views",
   "main": "index.js",
   "scripts": {

test/server.js

@@ -114,6 +114,55 @@ test('rendering a react view', function(t) {
   setup(options);
 });
 
+test('performance collector to be asserted to be a function', function(t) {
+
+  function underTest1() {
+    renderer.create({
+      performanceCollector: 'SOME_STRING_AND_NOT_FUNCTION'
+    });
+  }
+
+  function underTest2() {
+    renderer.create({
+      performanceCollector: console.dir
+    });
+  }
+
+  t.throws(underTest1);
+  t.doesNotThrow(underTest2);
+  t.end();
+});
+
+test('performance collector', function(t) {
+
+  var recorder = [];
+
+  function collector(stats) {
+    recorder.push(stats);
+  }
+
+  var options = {
+    engine: renderer.create({
+      performanceCollector: collector
+    }),
+    onSetup: function(done) {
+      inject('/profile', function(err, data) {
+        t.error(err);
+        t.strictEqual(typeof data, 'string');
+        t.strictEqual(recorder.length, 1);
+        t.strictEqual(Object.keys(recorder[0]).length, 4);
+        t.strictEqual(recorder[0].name, path.resolve(__dirname, 'fixtures/views', 'profile.js'));
+        t.strictEqual(typeof recorder[0].startTime, 'number');
+        t.strictEqual(typeof recorder[0].endTime, 'number');
+        t.strictEqual(typeof recorder[0].duration, 'number');
+        t.ok(recorder[0].endTime > recorder[0].startTime);
+        done(t);
+      });
+    }
+  };
+  setup(options);
+});
+
 test('all views get cleared from require cache in dev mode', function(t) {
   var options = {
     engine: renderer.create(),