class Rubocop::Cop::Style::AvoidPerlisms

This cop looks for uses of Perl-style global variables.

def on_gvar(node) 

def on_gvar(node)
  global_var, = *node
  global_var = global_var.to_s
  if PREFERRED_VARS[global_var]
    add_offence(
      :convention,
      node.loc.expression,
      "Prefer #{PREFERRED_VARS[global_var]} over #{global_var}."
    )
  end
  super
end