[ruby-talk:444215] Is this the correct behaviour of `super`

12 May 2023

      I have been investigating a test failure triggered by upgrading selenium-webdriver from v4.9.0 to v4.9.1. This has lead me to produce the following test code that demonstrates the problem which occurs as an interaction between capybara and selenium. The test produces the following error
...
wrong number of arguments (given 2, expected 0..1) (ArgumentError)
Here is some code that reproduces the error

-----8<-----8<-----8<-----8<-----8<-----8<------8<-----8<-----8<-----
require 'selenium/webdriver/atoms'
require 'selenium/webdriver/common'
require 'selenium/webdriver/version'

module DeprecationSuppressor
  def initialize(*)
    puts 'in DeprecationSuppressor::initialize'
    super
  end
end
Selenium::WebDriver::Logger.prepend DeprecationSuppressor

class Demo
  def initialize
    @logger = Selenium::WebDriver::Logger.new('Selenium', ignored: true)
    puts @logger.class
  end
end

Demo.new
-----8<-----8<-----8<-----8<-----8<-----8<------8<-----8<-----8<-----

Here is it failing

➜ ruby -v
ruby 3.2.2 (2023-03-30 revision e51014f9c0) [arm64-darwin22]
➜ ruby demo.rb
in DeprecationSuppressor::initialize
/Users/my/.rvm/gems/ruby-3.2.2@test/gems/selenium-webdriver-4.9.1/lib/selenium/webdriver/common/logger.rb:51:in `initialize': wrong number of arguments (given 2, expected 0..1) (ArgumentError)

The error is raised by the `super` call in the initialize method of the DeprecationSuppressor module.

Naming the arguments in the initialize method fixes the problem
e.g.

-----8<-----8<-----8<-----8<-----8<-----8<------8<-----8<-----8<-----
module DeprecationSuppressor
  def initialize(*args)
    puts 'in DeprecationSuppressor::initialize'
    super args
  end
end
Selenium::WebDriver::Logger.prepend DeprecationSuppressor
-----8<-----8<-----8<-----8<-----8<-----8<------8<-----8<-----8<-----

➜ ruby demo.rb
in DeprecationSuppressor::initialize
Selenium::WebDriver::Logger 

I have also found that using `initialize(...)` works too.

I've tested this on Ruby 3.2.2 and 3.1.4

For further context of the wider problem, here is the initialize method in selenium-webdriver 4.9.0 and 4.9.1
4.9.0: https://github.com/SeleniumHQ/selenium/blob/selenium-4.9.0/rb/lib/selenium/w...
4.9.1: https://github.com/SeleniumHQ/selenium/blob/selenium-4.9.1/rb/lib/selenium/w...
The difference being that two more named arguments have been added

Finally it looks to me as though the Capybara team are preparing to fix this in v3.9.1 (https://github.com/teamcapybara/capybara/issues/2666)

My question is whether Ruby is behaving correctly? It seems to me that the `super` call in the initialize(*) method should work.

[ruby-talk:444215] Is this the correct behaviour of `super`

mark_young＠hotmail.com