feat: allow interfaces to implement other interfaces

[santialbo]

This is a initial draft for allowing interfaces to implement other interfaces which is one of the features coming with graphql v15.
Things I've considered:

• No need to call t.implements with all the interfaces like it is required on grapqhl. It automatically pulls all the transitive "implements" when building the schema.
• Check for circular dependencies before building the types in order to avoid stack overflow exceptions.

Please let me know if you prefer this to be handled in another way or if you would like me to add more tests and what kind of tests you would like to see.

BTW: I missed having some sort of autoformatter when working on this. Seeing that you use prettier on https://github.com/graphql-nexus/nexus would you accept a PR adding it here with the same config?

closes #389

[tgriesser]

Cool stuff, definitely want to get this in here. Mind getting it up-to-date with develop?

No need to call t.implements with all the interfaces like it is required on grapqhl. It automatically pulls all the transitive "implements" when building the schema.

Sounds like a good feature!

Check for circular dependencies before building the types in order to avoid stack overflow exceptions.

Nice

BTW: I missed having some sort of autoformatter when working on this. Seeing that you use prettier on graphql-nexus/nexus would you accept a PR adding it here with the same config?

Yeah, it definitely used to be in here. I'm guessing with all the shuffling around with Prisma things it got lost in the mix. Feel free to add!

[codecov]

Codecov Report

Merging #496 into develop will increase coverage by 0.02%.
The diff coverage is 96.36%.

@@             Coverage Diff             @@
##           develop     #496      +/-   ##
===========================================
+ Coverage    93.56%   93.58%   +0.02%     
===========================================
  Files           42       42              
  Lines         2438     2480      +42     
  Branches       504      509       +5     
===========================================
+ Hits          2281     2321      +40     
- Misses         157      159       +2     

[jasonkuhrt]

Tests appear to be passing. NPM is having issues right now so can ignore that failure:

[jasonkuhrt]

Thanks @santialbo !