Method: ActionCable::TestHelper#assert_broadcast_on

Defined in:
actioncable/lib/action_cable/test_helper.rb

#assert_broadcast_on(stream, data, &block) ⇒ Object

Asserts that the specified message has been sent to the stream.

def test_assert_transmitted_message
  ActionCable.server.broadcast 'messages', text: 'hello'
  assert_broadcast_on('messages', text: 'hello')
end

If a block is passed, that block should cause a message with the specified data to be sent.

def test_assert_broadcast_on_again
  assert_broadcast_on('messages', text: 'hello') do
    ActionCable.server.broadcast 'messages', text: 'hello'
  end
end



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# File 'actioncable/lib/action_cable/test_helper.rb', line 116

def assert_broadcast_on(stream, data, &block)
  # Encode to JSON and back–we want to use this value to compare with decoded
  # JSON. Comparing JSON strings doesn't work due to the order if the keys.
  serialized_msg =
    ActiveSupport::JSON.decode(ActiveSupport::JSON.encode(data))

  new_messages = broadcasts(stream)
  if block_given?
    new_messages = new_broadcasts_from(new_messages, stream, "assert_broadcast_on", &block)
  end

  message = new_messages.find { |msg| ActiveSupport::JSON.decode(msg) == serialized_msg }

  error_message = "No messages sent with #{data} to #{stream}"

  if new_messages.any?
    error_message = new_messages.inject("#{error_message}\nMessage(s) found:\n") do |error_message, new_message|
      error_message + "#{ActiveSupport::JSON.decode(new_message)}\n"
    end
  else
    error_message = "#{error_message}\nNo message found for #{stream}"
  end

  assert message, error_message
end