RubyMine 2024.2 Help

Tutorial: Debug JavaScript in a Rails application

RubyMine provides the capability to debug client-side JavaScript code in a Rails application. In this tutorial, we'll show you how to debug JavaScript in Chrome. We'll use a sample Rails application with a JavaScript asset created in the Add a JavaScript asset to a Rails application tutorial. This application uses Webpacker to manage JavaScript modules.

Clone the sample Rails app

To clone the sample Rails application, follow the steps below:

  1. Check out the sample application as described in Check out a project from a remote host (git clone). In the URL field, insert the following address: https://github.com/rubyminedoc/rails_helloworld.git.

  2. Switch to the javascript branch.

  3. Specify the Ruby interpreter and install dependencies:

Enable the JavaScript debugger

RubyMine uses run/debug configurations as a unified way to run and debug applications. For Rails projects, RubyMine automatically creates the development and production run/debug configurations with the corresponding Rails environments. To debug JavaScript, we need to enable automatic running of the JavaScript debugger in the Rails configuration.

  1. Go to Run | Edit Configurations, and choose the automatically created Development: rails_helloworld configuration in the Rails group.

  2. Specify the following options:

    Enable JavaScript debugger in Rails
    • Enable the Run browser option and specify the following address: http://0.0.0.0:3000/welcome/index. This URL will be used to open the app/views/welcome/index.html.erb view referencing a debugged JavaScript asset.

    • Enable Start JavaScript debugger automatically when debugging.

Start debugging

To debug JavaScript code, follow the steps below:

  1. Open the app/javascript/packs/hello.js file and set a breakpoint on the first hello function call.

    Set a breakpoint
  2. To start debugging, press Ctrl twice and start typing the configuration name in the popup: Development: rails_helloworld. Then, select this configuration, press and hold down the Shift key (the dialog title changes to Debug) and press Enter.

  3. In the opened http://0.0.0.0:3000/welcome/index page, click the Hello! button. The debugger pauses its session on a breakpoint and enables you to examine the application state. You can learn more about debugging JavaScript from Debug JavaScript in Chrome.

    Examine a suspended program
Last modified: 11 February 2024