I'm struggling to find out whether Flipper should be able to memoize during the usage of Fibers within a single thread. We just happen to use graphql-ruby heavily, and it relies on fibers:

GraphQL::Dataloader uses Ruby’s Fiber, a lightweight concurrency primitive which supports application-level scheduling within a Thread. By using Fiber, GraphQL::Dataloader can pause GraphQL execution when data is requested, then resume execution after the data is fetched.

I notice Flipper relies on Thread.current[:flipper_instance] which you can see does not persist across Fiber boundaries:

> Flipper.instance.__id__
=> 418860
> Fiber.new { puts Flipper.instance.__id__ }.resume
470320
> Fiber.new { puts Flipper.instance.__id__ }.resume
475280
> Flipper.instance.__id__
=> 418860

I understand if catering to Fiber usage is outside the scope of Flipper's goals, but wanted to open a discussion for my (and others') future reference.