Specs

handle_batch(
  batcher :: atom(),
  messages :: [Broadway.Message.t()],
  batch_info :: Broadway.BatchInfo.t(),
  context :: term()
) :: [Broadway.Message.t()]

Invoked to handle generated batches.

It expects:

• batcher is the key that defined the batcher. This value can be set in the handle_message/3 callback using Broadway.Message.put_batcher/2.
• messages is the list of Broadway.Message structs in the incoming batch.
• batch_info is a Broadway.BatchInfo struct containing extra information about the incoming batch.
• context is the user defined data structure passed to start_link/2.

It must return an updated list of messages. All messages received must be returned, otherwise an error will be logged. All messages after this step will be acknowledged according to their status.

In case of errors in this callback, the error will be logged and the whole batch will be failed. This callback also traps exits, so failures due to broken links between processes do not automatically cascade.

For more information on batching, see the "Batching" section in the Broadway documentation.