action_cable_tests.rb

def test_broadcasts
  assert_broadcasts 'messages', 0
  ActionCable.server.broadcast 'messages', { text: 'hello' }
  assert_broadcasts 'messages', 1
end

def test_subscribed_with_room_number
  subscribe room_number: 1
  assert subscription.confirmed?
  assert_has_stream "chat_1"
  assert_has_stream_for Room.find(1)
end

def test_perform_speak
  subscribe room_number: 1
  perform :speak, message: "Hello, Rails!"
  assert_equal "Hello, Rails!", transmissions.last["text"]
end

def test_connects_with_cookies
  connect cookies: { user_id: users[:john].id }
  assert_equal "John", connection.user.name
end