Interesting idea to implement a proxy that does something on each new connection. I’ll have to think about that but very cool concept that lets this work for tests written in any language.

Will each testcase need to run migrations after connecting for the first time? Also, I’m used to using clients which lazily pool connections, do they still work with this model?

Op, I’d be curious what you think of my project pgtestdb, which takes a different approach: use a single server, but create new databases each time. Maybe there is some middle ground where a proxy creates a new cloned db after each connection? https://github.com/peterldowns/pgtestdb