Laravel Collection Macro: mapWithCast

Automatically cast values in Laravel collections when using mapWithCast with typed closures.

collect([['name' => 'John'], ['name' => 'Jane']])
    ->mapWithCast(fn (Fluent $data) => $data->name)

// Result: ['John', 'Jane']

📦 About

mapWithCast is a Laravel collection macro that enhances the map method by automatically casting each item in the collection to the type hinted in your closure. It saves you from manual casting and enforces better type safety, making your code cleaner and more expressive.

It supports both scalar types like int and string and complex Laravel-specific types like Collection, Fluent, and Stringable.

🚀 Installation

Install the package via Composer:

composer require derheyne/laravel-collection-mapwithcast

The macro will be automatically registered thanks to Laravel's package discovery.

🧠 Type Support

✅ Supported Types (Out of the Box)

• int
• float
• bool
• string
• array
• object
• Illuminate\Support\Carbon and Carbon\Carbon
• Illuminate\Support\Collection
• Illuminate\Support\Fluent
• Illuminate\Support\Optional
• Illuminate\Support\Stringable
• Illuminate\Support\Uri

⚙️ Extending with Custom Casters

Need to handle your own types or custom logic? You can register additional casters by publishing the config file:

php artisan vendor:publish --tag=laravel-collection-mapwithcast-config

This will create a config file where you can specify your own custom casters:

// config/mapwithcast.php

return [
    'casters' => [
        App\Caster\SpatieLaravelDataCaster::class
    ],
];

namespace App\Casters;

use dhy\LaravelMapWithCastMacro\Contract\Caster;
use Spatie\LaravelData\Data;

class SpatieLaravelDataCaster implements Caster
{
    public function qualifies(mixed $type): bool
    {
        if (! is_string($type)) {
            return false;
        }

        return is_subclass_of(object_or_class: $type, class: Data::class, allow_string: true);
    }

    /** @param  Data  $type */
    public function cast(mixed $value, mixed $type): Data
    {
        return $type::from($value);
    }
}

Now you can automatically cast the value into the specified laravel-data DTO:

use Spatie\LaravelData\Data;

class CustomerData extends Data {
    public function __construct(
        public string $prename,
        public string $surname,
        public string $city,
    ) {}   
}
collect([['prename' => 'Jane', 'surname' => 'Doe', 'city' => 'New York']])
    ->mapWithCast(fn (CustomerData $customer) => $customer->prename.' '.$customer->surname)

// Returns: ['Jane Doe']

📚 Examples

🧮 Convert and Process Numbers

$totals = collect(['10.50', '20.75', '30'])
    ->mapWithCast(fn (float $price) => $price * 1.2);

// Result: [12.6, 24.9, 36.0]

🧠 Cast to Laravel Collection

$sums = collect([[1, 2, 3], [4, 5, 6]])
    ->mapWithCast(fn (Collection $items) => $items->sum());

// Result: [6, 15]

🔄 Cast to Stringable

$slugs = collect(['Laravel Tips', 'PHP Tricks'])
    ->mapWithCast(fn (Stringable $str) => $str->slug());

// Result: ['laravel-tips', 'php-tricks']

🪡 Cast by specifying a custom caster

class CustomDataObject
{
    public function __construct(
        public string $value,
    ) {}
}

collect(['one', 'two', 'three'])
    ->mapWithCast(
        callback: fn (CustomDataObject $value) => 'Value: '.$value->value,
        caster: fn ($value, $type) => new $type($value),
    );

// Return ['Value: one', 'Value: two', 'Value: three']

✅ Testing

composer test

🧪 Compatibility

• Laravel 11.x, 12.x
• PHP 8.3+

License

The MIT License (MIT). Please see License File for more information.