A while back I played around with making my own implementation of Cap'n Proto in Rust and for that I really wanted a good test suite that covers corner cases. And so I started building that.
Because I thought that good test data might also be relevant to other implementations I tried making a setup that would be easily usable by other implementations so that you can compare your implementation to the reference C++ one.
It consists of schemas and messages as well as JSON representation of those messages as the capnp tool sees them. The idea is that most languages have some JSON library that you can use to read the JSON messages and you can then compare that to how your implementation reads the binary message.
I would love you hear your input.