To run this recipe, we will need a target URL.

We will use confess.js to analyze that target URL and produce a lightweight performance report.

Lastly, the script in this recipe runs against the demo site that is included with the book's sample code repository. To run that demo site, we must have Node.js installed. In a separate terminal, change to the phantomjs-sandbox directory (in the sample code's directory), and start the app with the following command:

node app.js

With the Node.js demo app running, make sure we are in the root directory for the book's sample code, and enter the following on the command line:

phantomjs lib/confess/confess.js http://localhost:3000/css-demo performance lib/confess/config.json

Something...