# frozen_string_literal: true
module ActionCable
# Provides helper methods for testing Action Cable broadcasting
module TestHelper
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
def after_teardown # :nodoc:
super
ActionCable.server.instance_variable_set(:@pubsub, @old_pubsub_adapter)
end
# 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
#
def assert_broadcasts(stream, number)
if block_given?
original_count = broadcasts_size(stream)
yield
new_count = broadcasts_size(stream)
actual_count = new_count - original_count
else
actual_count = broadcasts_size(stream)
end
assert_equal number, actual_count, "#{number} broadcasts to #{stream} expected, but #{actual_count} were sent"
end
# 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
#
def assert_no_broadcasts(stream, &block)
assert_broadcasts stream, 0, &block
end
# 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
#
def assert_broadcast_on(stream, data)
# 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?
old_messages = new_messages
clear_messages(stream)
yield
new_messages = broadcasts(stream)
clear_messages(stream)
# Restore all sent messages
(old_messages + new_messages).each { |m| pubsub_adapter.broadcast(stream, m) }
end
message = new_messages.find { |msg| ActiveSupport::JSON.decode(msg) == serialized_msg }
assert message, "No messages sent with #{data} to #{stream}"
end
def pubsub_adapter # :nodoc:
ActionCable.server.pubsub
end
delegate :broadcasts, :clear_messages, to: :pubsub_adapter
private
def broadcasts_size(channel)
broadcasts(channel).size
end
end
end
