class RSpec::Rails::Matchers::ActionCable::HaveStream

def base_message
  no_expected? ? "any stream started" : "stream #{expected_formatted} started, but have #{actual_formatted}"
end

def does_not_match?(subscription)
  !match(subscription)
end

def failure_message
  "expected to have #{base_message}"
end

def failure_message_when_negated
  "expected not to have #{base_message}"
end

def match(subscription)
  case subscription
  when ::ActionCable::Channel::Base
    @actual = subscription.streams
    no_expected? ? actual.any? : actual.any? { |i| expected === i }
  else
    raise ArgumentError, "have_stream, have_stream_from and have_stream_from support expectations on subscription only"
  end
end

def matches?(subscription)
  raise(ArgumentError, "have_streams is used for negated expectations only") if no_expected?
  match(subscription)
end

def no_expected?
  !defined?(@expected)
end