Upgrade guide: Laravel 11 to 12

{
  "require": {
    "laravel/framework": "^12.0"
  },
  "require-dev": {
    "phpunit/phpunit": "^11.0",
    "pestphp/pest": "^3.0"
  }
}

composer update

composer global update laravel/installer

laravel new my-app

cd my-app
npm install && npm run build
composer run dev

use Illuminate\Database\Eloquent\Concerns\HasUuids; // [tl! remove]
use Illuminate\Database\Eloquent\Concerns\HasVersion4Uuids as HasUuids; // [tl! add]

use Illuminate\Validation\Rules\File;

'photo' => 'required|image:allow_svg'

// or
'photo' => ['required', File::image(allowSvg: true)],

// config/filesystems.php
'local' => [
    'driver' => 'local',
    'root' => storage_path('app'),
],

// All schemas
$tables = Schema::getTables();

// Only the 'main' schema
$tables = Schema::getTables(schema: 'main');

$tables = Schema::getTableListing();
// ['main.migrations', 'main.users', 'blog.posts']

$tables = Schema::getTableListing(schema: 'main', schemaQualified: false);
// ['migrations', 'users']

// Laravel <= 11.x
$grammar = new MySqlGrammar;
$grammar->setConnection($connection);

// Laravel >= 12.x
$grammar = new MySqlGrammar($connection);

$prefix = $connection->getTablePrefix();

$result = Concurrency::run([
    'task-1' => fn () => 1 + 1,
    'task-2' => fn () => 2 + 2,
]);

// ['task-1' => 2, 'task-2' => 4]

class Example
{
    public function __construct(public ?Carbon $date = null) {}
}

$example = resolve(Example::class);

// Laravel <= 11.x: returns a Carbon instance
// Laravel >= 12.x: returns null

$request->mergeIfMissing([
    'user.last_name' => 'Otwell',
]);