Two cops crash when scanning code using super

[jonas054]

This code:

class Base
  def func
    "Hello"
  end
end

class Derived < Base
  def func
    super.slice(1..2)
  end
end

puts Derived.new.func

gives this stack dump:

/home/jonas/.rvm/gems/ruby-1.9.3-p194/gems/rubocop-0.6.0/lib/rubocop/cop/hash_literal.rb:12:in `block in inspect': undefined method `[]' for nil:NilClass (NoMethodError)
    from /home/jonas/.rvm/gems/ruby-1.9.3-p194/gems/rubocop-0.6.0/lib/rubocop/cop/cop.rb:84:in `block (2 levels) in each'
[...]
    from /home/jonas/.rvm/gems/ruby-1.9.3-p194/gems/rubocop-0.6.0/lib/rubocop/cop/cop.rb:83:in `each'
    from /home/jonas/.rvm/gems/ruby-1.9.3-p194/gems/rubocop-0.6.0/lib/rubocop/cop/hash_literal.rb:9:in `inspect'
    from /home/jonas/.rvm/gems/ruby-1.9.3-p194/gems/rubocop-0.6.0/lib/rubocop/cli.rb:74:in `block (2 levels) in run'
    from /home/jonas/.rvm/gems/ruby-1.9.3-p194/gems/rubocop-0.6.0/lib/rubocop/cli.rb:66:in `each'
    from /home/jonas/.rvm/gems/ruby-1.9.3-p194/gems/rubocop-0.6.0/lib/rubocop/cli.rb:66:in `block in run'
    from /home/jonas/.rvm/gems/ruby-1.9.3-p194/gems/rubocop-0.6.0/lib/rubocop/cli.rb:44:in `each'
    from /home/jonas/.rvm/gems/ruby-1.9.3-p194/gems/rubocop-0.6.0/lib/rubocop/cli.rb:44:in `run'
    from /home/jonas/.rvm/gems/ruby-1.9.3-p194/gems/rubocop-0.6.0/bin/rubocop:13:in `block in <top (required)>'
    from /home/jonas/.rvm/rubies/ruby-1.9.3-p194/lib/ruby/1.9.1/benchmark.rb:295:in `realtime'
    from /home/jonas/.rvm/gems/ruby-1.9.3-p194/gems/rubocop-0.6.0/bin/rubocop:12:in `<top (required)>'
    from /home/jonas/.rvm/gems/ruby-1.9.3-p194/bin/rubocop:19:in `load'
    from /home/jonas/.rvm/gems/ruby-1.9.3-p194/bin/rubocop:19:in `<main>'

So HashLiteral crashes. The same goes for ArrayLiteral if HashLiteral is disabled. I have a fix for the problem.

[bbatsov]

Nice catch.