laravel-systematic-debugging

Systematic Debugging for Laravel

Overview

Random fixes waste time and create new bugs in Laravel applications. Quick patches mask underlying issues.

Core principle: ALWAYS find root cause before attempting fixes. Symptom fixes are failure.

Violating the letter of this process is violating the spirit of debugging.

The Iron Law

NO FIXES WITHOUT ROOT CAUSE INVESTIGATION FIRST

If you haven't completed Phase 1, you cannot propose fixes.

When to Use

Use for ANY Laravel technical issue:

• Test failures
• Eloquent query issues
• Authentication/authorization bugs
• Validation failures
• Queue job failures
• Route errors
• Migration issues
• N+1 query problems
• Performance issues

Use this ESPECIALLY when:

• Under time pressure
• "Just one quick fix" seems obvious
• You've already tried multiple fixes
• Previous fix didn't work
• You don't fully understand the issue

The Four Phases

You MUST complete each phase before proceeding to the next.

Phase 1: Root Cause Investigation

BEFORE attempting ANY fix:

1. Read Error Messages Carefully

   SQLSTATE[23000]: Integrity constraint violation
   → Check foreign key constraints, not a code bug
   
   Class 'App\Models\Post' not found
   → Check namespace, run composer dump-autoload
   
   Method Illuminate\Database\Eloquent\Collection::save does not exist
   → get() returns Collection, not Model. Use first() or update()
   

2. Check Laravel Logs

   # Main Laravel log
   tail -f storage/logs/laravel.log
   
   # Check for specific errors
   grep "SQLSTATE" storage/logs/laravel.log
   
   # Clear logs if too large
   > storage/logs/laravel.log
   

3. Enable Debug Mode (Local Only)

   APP_DEBUG=true
   APP_ENV=local
   

4. Use Laravel Telescope

   composer require laravel/telescope --dev
   php artisan telescope:install
   php artisan migrate
   
   # Access at /telescope
   # View: Requests, Queries, Jobs, Events, Exceptions