Problem with chaining .merge()

[dgodovanets]

I've faced a really weird problem when merging streams: merging requires a kafka streams reference on the left-hand merger. By documentation, it had to work. I tried to use other method. Joining streams gives either the same error or not implemented error.

Here's my code part:

const {KafkaStreams} = require("kafka-streams");
const kafkaStreams = new KafkaStreams(config.kafkas);

const stream_1 = kafkaStreams.getKStream(config.kafka.topics[0]);
const stream_2 = kafkaStreams.getKStream(config.kafka.topics[1]);
const stream_3 = kafkaStreams.getKStream(config.kafka.topics[2]);
const stream_4= kafkaStreams.getKStream(config.kafka.topics[3]);
var mergedStream = stream_1
  .merge(stream_2)
  .merge(stream_3) // Error arises at this line
  .merge(stream_4);

By documentation, from .merge(stream) should be returned an object which can be treated both as a stream or a table. Also, .merge(stream) should work fine on a table also

I use npm@6.7.0, node@11.8.0 and kafka-streams@4.8.0

Upd: creating new KafkaStreams for each stream, giving them unique groupId didn't solve the problem

[krystianity]

should be fixed.