Upgrading to WaterDrop 2.8

PLEASE MAKE SURE TO READ AND APPLY THEM!

throw(:abort) No Longer Allowed To Abort Transactions

Replace:

producer.transaction do
  messages.each do |message|
    # Pipe all events
    producer.produce_async(topic: 'events', payload: message.raw_payload)
  end

  # And abort if more events are no longer needed
  throw(:abort) if KnowledgeBase.more_events_needed?
end

With:

producer.transaction do
  messages.each do |message|
    # Pipe all events
    producer.produce_async(topic: 'events', payload: message.raw_payload)
  end

  # And abort if more events are no longer needed
  raise(WaterDrop::AbortTransaction) if KnowledgeBase.more_events_needed?
end

return, break and throw No Longer Allowed Inside Transaction Block

Previously, transactions would abort if you exited early using return, break, or throw. This could create unexpected behavior, where users might not notice the rollback or have different intentions. For example, the following would trigger a rollback:

MAX = 10

def process(messages)
  count = 0

  producer.transaction do
    messages.each do |message|
      count += 1

      producer.produce_async(topic: 'events', payload: message.raw_payload)

      # This would trigger a rollback.
      return if count >= MAX
    end
  end
end

This is a source of errors, hence such exits are no longer allowed. You can implement similar flow control inside of your methods that are wrapped in a WaterDrop transaction:

MAX = 10

def process(messages)
  producer.transaction do
    # Early return from this method will not affect the transaction.
    # It will be committed
    insert_with_limit(messages)
  end
end

def insert_with_limit(messages)
  count = 0

  messages.each do |message|
    count += 1

    producer.produce_async(topic: 'events', payload: message.raw_payload)

    # This would trigger a rollback.
    return if count >= MAX
  end
end