class RSpec::Rails::Matchers::ActionCable::HaveBroadcastedTo

def matches?(proc)
  raise ArgumentError, "have_broadcasted_to and broadcast_to only support block expectations" unless Proc === proc
  original_sent_messages_count = pubsub_adapter.broadcasts(stream).size
  proc.call
  in_block_messages = pubsub_adapter.broadcasts(stream).drop(original_sent_messages_count)
  check(in_block_messages)
end