This reminds me of a forgotten project I did for a previous employer. We had a lot of MySQL databases and wanted to be able to run test environments that were much lighter than production. I implemented in Typescript the minimum of the MySQL network protocol so that it could be called from our applications, using an SQLite database as the real data store. It worked pretty well for our purposes, and it was tons of fun. Alas, I don't have access to that codebase anymore.