Add FactoryBot jump to the definition support

[lekemula]

I wondered about some sort of FactoryBot support - eg trying to jump to the definition for create(:blog_post) would jump me to the factory :blog_post do.... declaration.

Or, with regular Rails fixtures, whether blog_posts(:introduction) might be able to jump to fixtures/blog_posts.yml .

(Both sound quite hard to me, not sure what's possible).

Originally posted by @jdelStrother in #3 (comment)

[lekemula]

@jdelStrother thanks again for bringing this up. This is definitely one of the end-games in my mind and something hopefully we'll get to at some point! But as you've guessed that's not easy at all, and I won't be lying to you to say that this will come anytime soon-ish.

The problem is that currently, solargraph does not seem to support a way for go-to-definition based on method arguments, ie. create(:blog_post). If the DSL would be in the form of a method call like, create_blog_post(..params), that'd be more feasible. I faced the same issue when it came to supporting shared examples/contexts eg. include_example "some shared context".

Arguably the support for FactoryBot can be also seen as a separate plugin in itself, but I would be okay to start experimenting here and see where that leads us. However, I think that there are still lots of other low-hanging fruits to implement for RSpec itself, before moving to FactoryBot, and that's my focus right now. Once we have the "shared_examples" sorted, which I expect will involve changes upstream, only then I can start thinking on moving to factories.

What is more possible though, in current state of the affairs, is that we could bring the type inference based on the factories. In your example: create(:blog_post) => @return [BlogPost]. That's something I could probably implement much sooner.

[ShadiestGoat]

I've started working on this (for a POC at least), with my plan being to use overloads to have it work with different returns. Of course, this wouldn't work with "jump to definition", but will provide an almost perfect solution. (If it works)

[ShadiestGoat]

Hey, it looks like my POC worked! Unfortunately I can't open a proper PR or write up a plan or anything until my evening, but I just wanted to let you know that it is possible & I am gonna work on it!

[lekemula]

Appreciate you taking a stab at this @ShadiestGoat, having the factory bot return values properly inferred would be a great addition!

Of course, this wouldn't work with "jump to definition", but it will provide an almost perfect solution. (If it works)

Spoiler alert: I'm already looking into extending Solargraph to enable that ability by adding a new pin type to support "factory parameters", which looks very promising. That should obviate the need to use overloads for return types inference, but until I'm able to finalise the work, I'm fine to have this as an intermediary solution.

Looking forward to your PR!