gistfile1.txt

def expect
  begin
    yield
  rescue Exception => excn
    o = Struct.new(:excn).new(excn)
    def o.to(arg)
      arg.call(excn)
    end
    o
  end
end

def something
  raise
end

def raise_error(expected)
  Proc.new { |actual|
    yield [expected, actual]
  }
end

expect { something }.to raise_error(NotImplementedError) { |e| p e }