Even if you can query IdP Attribute Authority with resolvertest, and you can test the tiny details with a curl call, a ruby attribute authority client is handy should you desire, for instance, to bulk load the IdP with many parallel requests.
Moreover, the curl approach is very slow because you need to modify the request xml file to put a timely IssueInstant and a unique RequestID.
You can browse the source at the github project page
