<?php

use JoliCode\Slack\Api\Endpoint\ChatPostMessage;

final class FixedChatPostMessageEndpoint extends ChatPostMessage
{
    protected function getFormOptionsResolver(): \Symfony\Component\OptionsResolver\OptionsResolver
    {
        $optionsResolver = parent::getFormOptionsResolver();
        $optionsResolver->setDefined(['metadata']);
        $optionsResolver->setAllowedTypes('metadata', ['string']);
        return $optionsResolver;
    }
}


$slack->executeEndpoint(new FixedChatPostMessageEndpoint([
    'channel' => $channel,
    'text' => $text,
    'metadata' => $metadata,
]));