Rubocop: Idea: Cop for unnecessary `||=` operator in the initializer

[joromir]

Is your feature request related to a problem? Please describe.

I often stumble across code like this:

class Person
  def initialize(full_name)
    @full_name ||= full_name
  end

  # ...
end

Describe the solution you'd like

In this case, I find the ||= usage unnecessary as the #initialize method is called just once.

I believe that this is an offence and deserves a dedicated cop.

Thank you for your time and consideration. Would be happy to hear back from you.

Describe alternatives you've considered

Blank

Additional context

Blank

[mikegee]

I recently reviewed some code and recommended changing ||= to = in an initialize method. 👍

[jaredbeck]

👍 but, consider a constructor that calls super:

def initialize
  super
  @x ||= 1
end

The location of the super matters. Consider also:

include MaybeSetIvars
def initialize
  maybe_set_ivars # from MaybeSetIvars
  @x ||= 1
end

We could write an imperfect implementation that only registers obvious offenses. There's still some value in that.

[jaredbeck]

Cop added by https://github.com/rubocop-hq/rubocop/pull/6608