module Minitest::Hooks::ClassMethods

def before(type=nil, &block)

If type is :all, set the before_all hook instead of the before hook.
def before(type=nil, &block)
  if type == :all
   define_method(:before_all) do
      super()
      instance_exec(&block)
    end
    nil
  else
    super
  end
end