Throw exception on multi-level interface

[smyrick]

📝 Description

According to the spec, an interface can not implement another interface. This is not caught by our schema generator but instead just returns the first level interface as the type in the schema. We are now throwing an exception to help translate this understanding of GraphQL through the Kotlin code

Is this a breaking change? Someone may be using 1.0.0 today and just by updating their version they will have to fix something.

🔗 Related Issues

Resolves #419

[smyrick]

I would also be fine not merging this and just keeping the implementation today that only includes the first level

[codecov-io]

Codecov Report

Merging #420 into master will decrease coverage by 0.06%.
The diff coverage is 85.71%.

@@             Coverage Diff              @@
##             master     #420      +/-   ##
============================================
- Coverage     97.81%   97.74%   -0.07%     
- Complexity      325      326       +1     
============================================
  Files           105      106       +1     
  Lines          1236     1242       +6     
  Branches        204      207       +3     
============================================
+ Hits           1209     1214       +5     
  Misses            7        7              
- Partials         20       21       +1

Impacted Files	Coverage Δ	Complexity Δ
...up/graphql/exceptions/InvalidInterfaceException.kt	100% <100%> (ø)	1 <1> (?)
...p/graphql/generator/extensions/kClassExtensions.kt	100% <100%> (ø)	0 <0> (ø)	⬇️
...agroup/graphql/generator/types/InterfaceBuilder.kt	100% <100%> (ø)	2 <0> (ø)	⬇️
...oup/graphql/generator/filters/superclassFilters.kt	80% <50%> (-20%)	0 <0> (ø)

---

Continue to review full report at Codecov.

Legend - Click here to learn more
Δ = absolute <relative> (impact), ø = not affected, ? = missing data
Powered by Codecov. Last update f0b3590...449b198. Read the comment docs.

[smyrick]

Question for the team? Do we need to look multiple levels deep when resolving interfaces. Currently we only look one level from the class

[dariuszkuc]

Question for the team? Do we need to look multiple levels deep when resolving interfaces. Currently we only look one level from the class

I think supporting generation of the schema based on class -> common abstract (ignored) -> interface pattern might be useful. Currently we don't support that as we only look at direct ancestors.

[smyrick]

@dariuszkuc Updated to return multiple levels deep now