Summary

This PR adds a new Artisan command php artisan route:conflicts that analyzes registered routes and detects potential routing conflicts where two routes could match the same incoming request.

The Problem

Route conflicts are a common source of subtle bugs in Laravel applications. When a parameterized route is defined before a literal route, the parameter route may "shadow" the literal one:

// This route will match /users/admin with id="admin"
Route::get('/users/{id}', [UserController::class, 'show']);

// This route will NEVER be reached!
Route::get('/users/admin', [AdminController::class, 'dashboard']);

These conflicts are difficult to detect manually in large applications with hundreds of routes, and often only surface in production when users report unexpected behavior.

The Solution

The new route:conflicts command provides:

• Automatic conflict detection - Scans all routes and identifies potential conflicts
• Constraint awareness - Respects where() constraints (e.g., ->where('id', '[0-9]+') won't conflict with /users/admin)
• HTTP method checking - Only flags routes that share HTTP methods
• Detailed output - Shows URIs, route names, and controller actions for each conflict
• JSON output - --json flag for CI/CD pipeline integration
• Proper exit codes - Returns 0 for no conflicts, 1 when conflicts are found

Usage

# Basic usage - human-readable output
php artisan route:conflicts

# JSON output for CI/CD pipelines
php artisan route:conflicts --json

Example Output

CLI format:

🚨 Route conflicts found:
[GET,HEAD]
  Earlier: users/{id} (App\Http\Controllers\UserController@show)
  Later:   users/admin (App\Http\Controllers\AdminController@dashboard)

JSON format:

[
  {
    "methods": "GET,HEAD",
    "earlier": {
      "uri": "users/{id}",
      "name": "users.show",
      "action": "App\\Http\\Controllers\\UserController@show"
    },
    "later": {
      "uri": "users/admin",
      "name": "admin.dashboard",
      "action": "App\\Http\\Controllers\\AdminController@dashboard"
    }
  }
]

Conflict Detection Logic

The command detects conflicts when:

1. Two routes share at least one HTTP method
2. Routes have the same number of URI segments
3. For each segment position:
   • Both are literals and match, OR
   • At least one is a parameter that could match the other's value

The command correctly handles:

• Parameter constraints via where() clauses
• Multiple HTTP methods on a single route
• Closure and controller-based routes
• Named and unnamed routes

Why This Matters

• Development - Catch routing issues early during development
• Code Review - Quickly audit route files for potential problems
• CI/CD - Integrate into pipelines to prevent deployment of conflicting routes
• Debugging - Diagnose unexpected routing behavior in existing applications

Test Plan

• Test no conflicts detected with non-overlapping routes
• Test parameter vs literal conflict detection (/users/{id} vs /users/admin)
• Test parameter constraints prevent false positives
• Test parameter vs parameter conflict detection (/posts/{slug} vs /posts/{id})
• Test different HTTP methods don't conflict
• Test shared HTTP methods trigger conflict detection
• Test different segment counts don't conflict
• Test JSON output format and structure
• Test CLI output format
• Test multiple conflicts detection
• Test named routes included in output
• Test complex non-overlapping URIs
• Test controller-based routes
• Test literal-first ordering doesn't report false conflicts

Files Changed

• src/Illuminate/Foundation/Console/RouteConflictsCommand.php - New command implementation
• src/Illuminate/Foundation/Providers/ArtisanServiceProvider.php - Command registration
• tests/Foundation/Console/RouteConflictsCommandTest.php - Comprehensive test suite

Now developers can also verify route integrity with route:conflicts.