introspection_fun.rb

def inspect_class(klass)
  klass.new.methods.sort.each do |meth|
    just = klass.new.methods.sort.max_by(&:length).length
    hjust = just / 2
    klass_meth   = klass.new.method(meth)

    label = "#{klass}.new.#{meth.to_s.ljust(just)}"
    location = "is defined in #{klass_meth.owner.to_s.ljust(hjust)}"

    response = [label, location]

    next if meth =~ /(pry|binding)/

    begin
      return_value = klass_meth.call
      return_klass = return_value.class

      if return_klass.to_s =~ /^[AEIOU]/
        response << "returns an #{return_klass}"
      else
        response << "returns a  #{return_klass}"
      end

    rescue StandardError => e
      response << "throws #{e.class}"
      if e.is_a?(ArgumentError)
        response <<  "because #{meth.to_sym.inspect.ljust(hjust)} requires #{klass_meth.arity} argument#{"s" if klass_meth.arity > 1}"
      end
    ensure
      puts response.join(", ")
    end
  end
end

inspect_class(Array)