Sunday, 26 April 2015

Getting Started with Benchpress

Lately, most of us are quite busy with writing great front-end centric applications to make the look and feeling of our apps jazzy. Despite of the jazziness, the application won’t give a great experience to the user unless it performs really well on the browser. Performance of any piece of code can be improved only if we know that there is some scope for the improvement. Benchpress is one of the tools available to measure performance of AngularJS applications. In this post, we will see how to install benchpress and get started with using the data it provides us.

Benchpress is a performance measuring tool built on top of Protractor. It is built by the Angular team and is extensively used by them to measure performance of the framework. It is made available and can be used by anyone to measure performance of the Angular apps.

Installing Benchpress

Benchpress is an NPM package. So, it needs Node.js to be installed. As it uses protractor, you need to install protractor globally. Use the following command to install protractor:

npm install –g protractor

If you are installing it on a Windows machine, webdriver-manager may throw an error. To oversome this, you will have to update the webdriver-manager. Following command updates it:

webdriver-manager update

Restart the command prompt after this command completes execution.
Install protractor again after updating the webdriver-manager and it shouldn’t fail this time. You can find more details on installing protractor in its official documentation on GitHub.
Now that the system has protractor available as a global package, we can install benchpress. Benchpress also has to be installed globally. Following is the command:

npm install -g generator-benchpress

Getting a Glimpse of Benchpress ng-tasty
Now that we have all of the required setup, we can apply benchpress on a project. For this post, I will show the benchpress results using the yeoman scaffold of ng-tasty. I will explain the process of getting benchpress results on an existing piece of code in a future article. As we need to install a yeoman scaffold, you must have yeoman installed. If you don’t already have, run the following command to install it:

npm install –g yo

Create a new folder at your desired location and install the following NPM packages locally:
  • http-server
  • benchpress


Benchpress needs these packages to start the Node.js HTTP server and run the scenarios tests. The final thing that we need to get is, the yeoman scaffold. Run the following command in the same folder where the above NPM packages are installed: yo benchpress ng-tasty

This scaffold adds a folder called benchmarks and inside this folder and the folder has following content:
  • protractorBenchmarks.conf.js: It is the configuration file for benchpress. It contains the browser details, spec files to run, test framework to use, the task to be performed before launching benchpress and a config object for jasmine
  • index.html: This file is inside the ng-tasty folder and it is the page to be inspected on
  • benchmark.spec.js: This file is inside the ng-tasty folder. The spec file that uses Selenium web driver to perform operations on the page
Now, we have everything to run benchpress and see some results. Run the following command on the console and see the outcome:

protractor benchmarks\protractorBenchmarks.conf.js

This command starts Selenium Web Driver and loads the index.html on Chrome. It performs the set of operations configured and prints results on the console.


Happy coding!

3 comments:

  1. I am getting this err

    description: failed loading configuration file benchmarks\protractorBenchmarks.conf.js


    Can you please help me?

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  2. This comment has been removed by the author.

    ReplyDelete
  3. Nice post! :)

    But I'm getting this error:

    Error: Error: Cannot find module 'benchpress/src/webdriver/selenium_webdriver_adapter'

    Seems like the benchpress module has changed. Anyone know the correct path for this?

    ReplyDelete