Allow testing against a deployed site

[cburgmer]

In some instances we might not be able to integrate testing into the application and run tests against a local code base. The same origin restriction doesn't allow us to test against a deployed website served from a different origin.

[cburgmer]

A quick solution is to run that through a CORS proxy like https://github.com/cburgmer/tinycors.

[cburgmer]

Latest commits including ae2864d tackle this by routing all pages under test through a backend.

TODO:

• Support URLs without host part together with full ones
• Remove script elements once inlined to work around duplicate call
• Report failed resources
• Add caching parameters
• Sandbox JS execution in backend
• Add a bit of user niceness to server

[zeroxme]

+1

[cburgmer]

Here's an idea how to do it right now:

1. Grab fzaninotto/screenshot-as-a-service and start the service

2. Register a page like that:

    csscritic.add('http://localhost:3000/?url=https://github.com');

   This should get you started. I'd be happy about feedback, and willing to add some more functionality around that, although this is currently not my main area of focus.

[cburgmer]

CSS Critic moves towards providing tests around a style guide. This aims for small components instead of full blown pages.

Having said that, CSS Critic loads both HTML and just simple images from any given URL as long as it's allowed to access those resources following the same origin policy. Solutions mentioned above will provide flexibility around accessing more complex resources.