Make it clear that the cache store can be required

[frenkel]

In order to prevent issues such as #225

[grzuy]

Sounds good to me

[grzuy]

Well, thinking again, you don't necessarily need to configure it. It depends whether it's defaulting to Rails.cache or not... right?

Changed my mind after reviewing second time

[lmansur]

The gem uses Rails.cache as a fall back in case you didn't configure Rack::Attack::Cache.store. Depending on your Rails version, Rails.cache in development environment uses NullStore, which doesn't actually store anything.

I think we could add some kind of notice regarding this possible case to avoid unnecessary debugging.

[grzuy]

Agree.

E.g. #274 was an attempt to aid users in debugging store config errors, but there's definitely room for more improvement. Either by giving better warning/errors and/or clearer docs.

[grzuy]

Created a new issue to track that need: #300

[grzuy]

Closing this PR for now given the conversation stalled, plus there were other changes which were trying to solve the same confusion as part of #300.

@frenkel Thank you for trying to contribute anyway. Let me know if you still think what you were trying to solve isn't yet covered, so we can continue discussing how to do that.