Cop for raise arguments doesn't account for a splat operator

[mattdowdell]

Related to #552.

The following example causes an offense:

class MyException < StandardError
  def initialize(message, other_arg)
    super "#{message.inspect} -- #{other_arg.inspect}"
  end
end

args = ['message', 'other argument']

begin
  raise MyException.new(*args)
rescue MyException => exc
  puts exc.message
end

The offense here being "Provide an exception class and message as arguments to raise."

I think the example is relatively self explanatory in what it's trying to achieve, but let me know if there's any questions.

Expected behavior

Rubocop should either not have a problem with use of the splat operator in this case, or detect if the array has more than one argument before raising the offense.

RuboCop version

$ rubocop -V
0.43.0 (using Parser 2.3.1.4, running on ruby 2.3.0 x86_64-linux)

[jonas054]

Rubocop should either not have a problem with use of the splat operator in this case, or detect if the array has more than one argument before raising the offense.

Yes. I think we should contend ourselves with not reporting when the splat operator is used, like in raise MyException.new(*args). Determining the size of the array is just too hard, generally speaking.