Something for #ruby folks who have to deal with SAML, particularly when operating as a service provider:
I and my colleagues have just released a gem that provides a micro IdP for use within feature specs, so you can have a full SSO flow tested. As a bonus, you can also use it in your development environment to avoid needing an external service for manual testing. The gem is called ssolo. ☺️
https://github.com/covidence/ssolo