Open sourcing h3i: a command line tool and library for low-level HTTP/3 testing and debugging

What this post added

This post introduces h3i, a new open-source command-line tool and Rust library for low-level HTTP/3 testing and debugging. It details the motivation behind its development, its role in ensuring standards-compliant software and production systems, and provides guidance on its usage. The post also includes a recap of QUIC and HTTP/3, and background on Cloudflare's existing testing methodologies for these protocols, highlighting the need for more accessible and maintainable tools like h3i to test edge cases and protocol deviations.