frame aggregation test coverage

[flrgh]

In the default case it makes sense to be as transparent as possible, forwarding all frames as-is. When aggregate_fragments is turned on, however, we are no longer a completely neutral intermediary, so we need to do a little more work to detect protocol errors and incorrect behavior.

This is a test suite for WebSockets with many helpful test cases around fragmentation. It would be good to implement this in CI or translate the fragmentation test cases into Test::Nginx::Socket.

[flrgh]

It might make sense to factor out the fragment aggregation into another module that wraps resty.websocket.{client,server} and presents a more high-level WebSocket API for send/recv (easier to test that way as well).

[flrgh]

@thibaultcha before I break ground on any of this, do you have a strong opinion on using GH actions + Autobahn vs adding some tests to our existing Test::Nginx::Socket corpus? Seems like they each require a medium amount of effort and have tradeoffs:

• Autobahn
  • 👍 all test cases already written for us
  • 👎 still some overhead to set up (need to write a small test driver)
  • 👎 not as tightly-integrated / more effort required to run tests locally
• Test::Nginx::Socket
  • 👍 integrated with existing test suite
  • 👎 much more code to write to achieve similar level of test coverage

[thibaultcha]

No opinion.