Rails Debugging Guide

This skill provides a systematic approach to debugging Ruby on Rails applications, covering common error patterns, modern debugging tools, and proven troubleshooting techniques.

Common Error Patterns

1. ActiveRecord::RecordNotFound

Symptoms: Rails fails to find a record in the database when using find or find_by! methods.

Diagnosis:

# Check if record exists
rails console
> Model.exists?(id)
> Model.where(conditions).count