Module: ActionCable::TestHelper

Relationships & Source Files
Extension / Inclusion / Inheritance Descendants
Included In: `Channel::TestCase`, `Channel::TestCase::Behavior`, `TestCase`
Defined in:	actioncable/lib/action_cable/test_helper.rb

Overview

Provides helper methods for testing Action Cable broadcasting

Instance Attribute Summary

#broadcasts readonly
#clear_messages readonly

Instance Method Summary

#assert_broadcast_on(stream, data, &block)

Asserts that the specified message has been sent to the stream.
#assert_broadcasts(stream, number, &block)

Asserts that the number of broadcasted messages to the stream matches the given number.
#assert_no_broadcasts(stream, &block)

Asserts that no messages have been sent to the stream.
#capture_broadcasts(stream, &block)

Returns the messages that are broadcasted in the block.
#new_broadcasts_from(current_messages, stream, assertion, &block) private
#after_teardown Internal use only
#before_setup Internal use only
#pubsub_adapter Internal use only

Instance Attribute Details

#broadcasts (readonly)

[ GitHub ]

# File 'actioncable/lib/action_cable/test_helper.rb', line 146


delegate :broadcasts, :clear_messages, to: :pubsub_adapter

#clear_messages (readonly)

[ GitHub ]

# File 'actioncable/lib/action_cable/test_helper.rb', line 146


delegate :broadcasts, :clear_messages, to: :pubsub_adapter

Instance Method Details

#after_teardown

This method is for internal use only.

[ GitHub ]

# File 'actioncable/lib/action_cable/test_helper.rb', line 18


def after_teardown # :nodoc:
  super
  ActionCable.server.instance_variable_set(:@pubsub, @old_pubsub_adapter)
end

#assert_broadcast_on(stream, data, &block)

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

[ GitHub ]

# 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

#assert_broadcasts(stream, number, &block)

Asserts that the number of broadcasted messages to the stream matches the given number.

def test_broadcasts
  assert_broadcasts 'messages', 0
  ActionCable.server.broadcast 'messages', { text: 'hello' }
  assert_broadcasts 'messages', 1
  ActionCable.server.broadcast 'messages', { text: 'world' }
  assert_broadcasts 'messages', 2
end

If a block is passed, that block should cause the specified number of messages to be broadcasted.

def test_broadcasts_again
  assert_broadcasts('messages', 1) do
    ActionCable.server.broadcast 'messages', { text: 'hello' }
  end

  assert_broadcasts('messages', 2) do
    ActionCable.server.broadcast 'messages', { text: 'hi' }
    ActionCable.server.broadcast 'messages', { text: 'how are you?' }
  end
end

[ GitHub ]

# File 'actioncable/lib/action_cable/test_helper.rb', line 48


def assert_broadcasts(stream, number, &block)
  if block_given?
    new_messages = new_broadcasts_from(broadcasts(stream), stream, "assert_broadcasts", &block)

    actual_count = new_messages.size
    assert_equal number, actual_count, "#{number} broadcasts to #{stream} expected, but #{actual_count} were sent"
  else
    actual_count = broadcasts(stream).size
    assert_equal number, actual_count, "#{number} broadcasts to #{stream} expected, but #{actual_count} were sent"
  end
end

#assert_no_broadcasts(stream, &block)

Asserts that no messages have been sent to the stream.

def test_no_broadcasts
  assert_no_broadcasts 'messages'
  ActionCable.server.broadcast 'messages', { text: 'hi' }
  assert_broadcasts 'messages', 1
end

If a block is passed, that block should not cause any message to be sent.

def test_broadcasts_again
  assert_no_broadcasts 'messages' do
    # No job messages should be sent from this block
  end
end

Note: This assertion is simply a shortcut for:

assert_broadcasts 'messages', 0, &block

[ GitHub ]

# File 'actioncable/lib/action_cable/test_helper.rb', line 80


def assert_no_broadcasts(stream, &block)
  assert_broadcasts stream, 0, &block
end

#before_setup

This method is for internal use only.

[ GitHub ]

# File 'actioncable/lib/action_cable/test_helper.rb', line 8


def before_setup # :nodoc:
  server = ActionCable.server
  test_adapter = ActionCable::SubscriptionAdapter::Test.new(server)

  @old_pubsub_adapter = server.pubsub

  server.instance_variable_set(:@pubsub, test_adapter)
  super
end

#capture_broadcasts(stream, &block)

Returns the messages that are broadcasted in the block.

def test_broadcasts
  messages = capture_broadcasts('messages') do
    ActionCable.server.broadcast 'messages', { text: 'hi' }
    ActionCable.server.broadcast 'messages', { text: 'how are you?' }
  end
  assert_equal 2, messages.length
  assert_equal({ text: 'hi' }, messages.first)
  assert_equal({ text: 'how are you?' }, messages.last)
end

[ GitHub ]

# File 'actioncable/lib/action_cable/test_helper.rb', line 96


def capture_broadcasts(stream, &block)
  new_broadcasts_from(broadcasts(stream), stream, "capture_broadcasts", &block).map { |m| ActiveSupport::JSON.decode(m) }
end

#new_broadcasts_from(current_messages, stream, assertion, &block) (private)

[ GitHub ]

# File 'actioncable/lib/action_cable/test_helper.rb', line 149


def new_broadcasts_from(current_messages, stream, assertion, &block)
  old_messages = current_messages
  clear_messages(stream)

  _assert_nothing_raised_or_warn(assertion, &block)
  new_messages = broadcasts(stream)
  clear_messages(stream)

  # Restore all sent messages
  (old_messages + new_messages).each { |m| pubsub_adapter.broadcast(stream, m) }

  new_messages
end

#pubsub_adapter

This method is for internal use only.

[ GitHub ]

# File 'actioncable/lib/action_cable/test_helper.rb', line 142


def pubsub_adapter # :nodoc:
  ActionCable.server.pubsub
end