Custom route binding for backed enums doesn't work

[Lukasss93]

Laravel Version

11.7.0

PHP Version

8.3.3

Database Driver & Version

No response

Description

We're using a custom route binding for a backed enum in our Laravel application.

To avoid having to create a new backed enum (string) for plural words, we've been using a custom route binding to resolve the enum from plural words.

For single words, it works fine. But for plural words, it doesn't work anymore, giving the following error:

Object of class App\Enums\YourEnumHere could not be converted to string

⚠️ See the "Steps To Reproduce" section below for more details.

Possible Solution

Do not implicitly resolve backed enums when there is a custom route binding.

Steps To Reproduce

1. Create a backed enum

<?php

namespace App\Enums;

enum Fruit:string
{
    case APPLE = 'apple';
    case BANANA = 'banana';
    case PEAR = 'pear';

    public static function fromPlural(string $plural): self
    {
        return match ($plural) {
            'apples' => self::APPLE,
            'bananas' => self::BANANA,
            'pears' => self::PEAR,
        };
    }
}

2. Add custom route binding to the AppServiceProvider.php

Route::bind('fruits', fn(string $x) => Fruit::fromPlural($x));

3. Add a route to the web.php file

Route::get('shop/get/{fruit}/{id}', function (App\Enums\Fruit $fruit, string $id) {
    dd($fruit, $id); // IT WORKS!!!
});

Route::get('shop/list/{fruits}', function (App\Enums\Fruit $fruits) {
    dd($fruits); // ERROR: Object of class App\Enums\Fruit could not be converted to string
});