adrema/database/factories/UserFactory.php

<?php

namespace Database\Factories;

use App\User;
use Illuminate\Database\Eloquent\Factories\Factory;
use Illuminate\Support\Facades\Hash;

/**
 * @extends Factory<User>
 */
class UserFactory extends Factory
{
    protected $model = User::class;

    /**
     * Define the model's default state.
     *
     * @return array<string, mixed>
     */
    public function definition()
    {
        return [
            'email' => $this->faker->safeEmail,
            'password' => Hash::make('password'),
            'firstname' => $this->faker->firstName,
            'lastname' => $this->faker->lastName,
        ];
    }

    public function name(string $name): self
    {
        [$firstname, $lastname] = explode(' ', $name);
        return $this->state(['firstname' => $firstname, 'lastname' => $lastname]);
    }

    public function email(string $email): self
    {
        return $this->state(['email' => $email]);
    }
}