Type-safe PHP collections based on Laravel Collections

[!NOTE]
Laravel 11 added the ensure() collection method that verifies that all elements of a collection are of a given type or list of types. However, this verification does not prevent items of different types to be added at a later time.

[!NOTE]
If you use Laravel collections combined with Larastan/PHPStan, you won't need this library and can just™ annotate your collection classes directly.

Installation

The package can be installed with Composer:

$ composer require gamez/typed-collection

Usage

class Person
{
    public $name;

    public function __construct($name)
    {
        $this->name = $name;
    }
}

$taylor = new Person('Taylor');
$jeffrey = new Person('Jeffrey');

Typed Collections

use Gamez\Illuminate\Support\TypedCollection;

/**
 * @extends TypedCollection<array-key, Person> 
 */
class People extends TypedCollection
{
    protected static array $allowedTypes = [Person::class];
}

$people = People::make([$taylor, $jeffrey])
    ->each(function (Person $person) {
        printf("This is %s.\n", $person->name);
    });
/* Output:
This is Taylor.
This is Jeffrey.
*/

try {
    People::make('Not a person');
} catch (InvalidArgumentException $e) {
    echo $e->getMessage().PHP_EOL;
}
/* Output:
Output: A People collection only accepts items of the following type(s): Person.
*/

Lazy Typed Collections

use Gamez\Illuminate\Support\LazyTypedCollection;

/**
 * @extends LazyTypedCollection<array-key, Person> 
 */
class LazyPeople extends LazyTypedCollection
{
    protected static array $allowedTypes = [Person::class];
}

$lazyPeople = LazyPeople::make([$taylor, $jeffrey])
    ->each(function (Person $person) {
        printf("This is %s.\n", $person->name);
    });
/* Output:
This is Lazy Taylor.
This is Lazy Jeffrey.
*/

try {
    LazyPeople::make('Nope!');
} catch (InvalidArgumentException $e) {
    echo $e->getMessage().PHP_EOL;
}
/* Output:
Output: A People collection only accepts objects of the following type(s): Person.
*/

Mixed collections

/**
 * @extends LazyTypedCollection<array-key, int|string|Person> 
 */
class MixedTypeCollection extends TypedCollection
{
    protected static array $allowedTypes = ['int', 'string', Person::class];
}

Supported types

Supported types are class strings, like Person::class, or types recognized by the get_debug_type() function, int, float, string, bool, and array.

Helper functions

The typedCollect() helper function enables you to dynamically create typed collections on the fly:

$dateTimes = typedCollect([new DateTime(), new DateTime()], DateTimeInterface::class);

For further information on how to use Laravel Collections, have a look at the official documentation.