Federation example

[smyrick]

Add a federation example with two running spring boot apps and a Node.js app running @apollo/gateway

Here is a query sent to the gateways which resolves data directly from both apps, and also runs a query from base-app (getWidgetById) by then is extended with data from extend-app

[dariuszkuc]

@smyrick as per the federation docs workaround around graphql-java limitation is to use @extends directive instead (link)

[smyrick]

@dkuc84 Ah I missed that, ok that means graphql-kotlin-federation has a bug right now because the type Query does not have this directive on it

[dariuszkuc]

@smyrick SDL used by federation is correct but yes there is a mismatch between generated Query type and the SDL returned by the _service { sdl } (https://github.com/ExpediaDotCom/graphql-kotlin/blob/master/graphql-kotlin-federation/src/main/kotlin/com/expedia/graphql/federation/FederatedSchemaGeneratorHooks.kt#L69).

[codecov]

Codecov Report

Merging #315 into master will increase coverage by 0.02%.
The diff coverage is 100%.

@@             Coverage Diff              @@
##             master     #315      +/-   ##
============================================
+ Coverage     93.56%   93.58%   +0.02%     
  Complexity      267      267              
============================================
  Files            76       77       +1     
  Lines           963      967       +4     
  Branches        176      175       -1     
============================================
+ Hits            901      905       +4     
  Misses           36       36              
  Partials         26       26

Impacted Files	Coverage Δ	Complexity Δ
.../graphql/federation/directives/ExtendsDirective.kt	100% <100%> (ø)	0 <0> (?)
...raphql/federation/FederatedSchemaGeneratorHooks.kt	100% <100%> (ø)	7 <0> (ø)	⬇️
...ia/graphql/generator/extensions/kTypeExtensions.kt	100% <0%> (ø)	0% <0%> (ø)	⬇️

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[dariuszkuc]

Maybe we should put all examples under single example folder?, e.g.

graphql-kotlin
- graphql-kotlin-federation
- graphql-kotlin-schema-generator
- examples
|- spring
|- federation
  |- base-app
  |- extend-app
  |- gateway 

thoughts?

[smyrick]

Yea, I was thinking about that. It would make the top level easier to look at. I will update

[dariuszkuc]

is there a way we could run both examples during build? unsure about travis but maybe we could utilize github actions?

[smyrick]

@dkuc84 I would love to start using actions, but we need the org admins to opt-in to the feature.

Right now the maven modules are at least compiled