How to verify an link points to the right image and has the right target and title

Question

I am using capybara with cucumber in rails 2.3.9 application.

Here is my html code

<a href="http://twitter.com/dorelal" target="_blank" title="twitter">
  <img alt="twitter" src="/images/social/twitter.png?1284129939" />
</a>

I want to verify following items

image should be ending with twitter.png
image alt should be "twitter"
link should have href "http://twitter.com/dorelal"
link should have target "_blank"
link should have title "twitter"