Callstacking::Rails

Call Stacking is a rolling, checkpoint debugger for Rails. It records all of the critical method calls within your app, along with their important context (param/argument/return/local variable values).

You no longer need to debug with binding.pry or puts statements, as the entire callstack for a given request is captured.

Demo video:

Class method calls are labeled. Return values for those calls are denoted with ↳

Arguments for a method will be listed along with their calling values.

For method returns ↳, the final values of the local variables will be listed when you hover over the entry.

Subsequent calls within a method are visibly nested.

Call Stacking is a Rails engine that you mount within your Rails app.

Here's a sample debugging sessions recorded from a Jumpstart Rails based app I've been working on. This is a request for the main page ( https://smartk.id/ ).

Call Stacking Rails records all of the critical method calls within your app, along with their important context (param/argument/return/local variable values).

All in a rolling panel, so that you can debug your call chains from any point in the stack.

You'll never have to debug with puts statements ever again.

Calls are visibly nested so that it's easy to see which calls are issued from which parent methods.

Installation

Add this line to your application's Gemfile:

gem "callstacking-rails"

And then execute:

$ bundle

CLI Setup

Step 1:

bundle exec callstacking-rails register

The above command will open a browser window and allow you to register an account at callstacking.com.

Step 2:

bundle exec callstacking-rails setup

This interactively prompts you for your callstacking.com username/password.

The auth details are stored in ~/.callstacking.

Enabling Tracing

Call Stacking provides a helper method callstacking_setup that you can use to enable tracing for a given request.

You control how you enable tracing.

Here's a sample setup to add tracing to your requests that both checks for the current user to be an admin and for a debug param to be set to 1:

class ApplicationController < ActionController::Base
  include Callstacking::Rails::Helpers::InstrumentHelper

  prepend_around_action :callstacking_setup, if: -> { current_user&.admin? && params[:debug] == '1' }

For the above setup, you would you have to be authenticated as an admin and would append ?debug=1 to the URL you wish to trace.

e.g.

• http://localhost:3000/?debug=1
• http://example.com/?debug=1

The local Rails server log outputs the trace URL.

Production Environment

For production, you can provide the auth token via the CALLSTACKING_API_TOKEN environment variable.

Your API token values can be viewed at https://callstacking.com/api_tokens

The traces are recorded at https://callstacking.com/traces

Local Development: Heads Up Debugger

For local HTML requests, once your page has rendered, you will see a 💥 icon on the right hand side.

Click the icon and observe the trace.

Headless API requests

The trace URL is output via the Rails logs. https://callstacking.com/traces will updated with your latest trace.

Tests

rake app:test:all

Questions/Bugs/Feature Requests

Create an issue: https://github.com/callstacking/callstacking-rails/issues

License

The license can be viewed at https://github.com/callstacking/callstacking-rails/blob/main/LICENSE