Adjust KafkaConsumerMessage to always return an array for headers

[antonkomarev]

Jobcloud\Kafka\Message\KafkaConsumerMessage right now has this signature:

public function __construct(
    string $topicName,
    int $partition,
    int $offset,
    int $timestamp,
    $key,
    $body,
    ?array $headers
) {

Is there any reason why headers is nullable? What are the use cases for null value?

I see that headers are casting to array right now:

return new KafkaConsumerMessage(
    (string) $message->topic_name,
    (int) $message->partition,
    (int) $message->offset,
    (int) $message->timestamp,
    $message->key,
    $message->payload,
    (array) $message->headers
);

[nick-zh]

@antonkomarev not everybody leverages the usage of headers, so they might be null on Kafka side

[antonkomarev]

Okay, but you are casting them to array, why KafkaConsumerMessage headers param is nullable then? As for me empty array means that there is no headers as well as null value

[nick-zh]

@antonkomarev is a good point, i don't remember anymore why we cast it. Maybe we always wanted to return an array but forgot to change the method signature. I'll need to check ✌️

[nick-zh]

@antonkomarev sry for the delay, so i definitely think, this was an oversight on our side. I agree that we should fix that, but since either way (adjusting the interface or removing the array cast) will break the behaviour, we'll need to put it into the next major.

[antonkomarev]

You are right, that's BC break. Will look forward to it!

[nick-zh]

Thanks again for that input btw 🙏