hello, I'm trying to figure out the proper way to ...

# coroutines

[Dariusz Kuc]

hello, I'm trying to figure out the proper way to do interop between reactor and coroutines - I need to populate reactor subscriber context with value computed from coroutine.

[Dariusz Kuc]

i tried doing something like this https://github.com/dariuszkuc/graphql-kotlin/blob/spring_server/graphql-kotlin-spring-server/src/main/kotlin/com/expediagroup/graphql/spring/execution/ContextWebFilter.kt#L38

[Dariusz Kuc]

but it fails unit test with step verifier -> https://github.com/dariuszkuc/graphql-kotlin/blob/spring_server/graphql-kotlin-spring-server/src/test/kotlin/com/expediagroup/graphql/spring/execution/ContextWebFilterTest.kt#L44

[gildor]

Probably make sense to ask in #spring or check their implementation, as I remember the last versions of Spring provide some integration with reactor context for coroutines

[Dariusz Kuc]

yeah already did and waiting for response

[withoutclass]

Latest spring supports coroutines and should not require special interop

[Dariusz Kuc]

also as a side note -> that webfilter logic does seem to work fine as when i start the spring boot app it properly populates it

[gildor]

https://github.com/Kotlin/kotlinx.coroutines/issues/284

[Dariusz Kuc]

might be just unit test

[Dariusz Kuc]

yeah it "should" work 🙂

[withoutclass]

https://www.baeldung.com/spring-boot-kotlin-coroutines

[gildor]

I'm not familiar with reactor, but curious what kind integration so you need, what you want to achieve

[Dariusz Kuc]

well i'm trying to have some unit test for verifying the context is populated right

[Dariusz Kuc]

so that step verifier tests worked fine when i used regular method to calculate value to be stored in the reactor subscriber context

[Dariusz Kuc]

but unfortunately it broke when i moved to coroutines

[Dariusz Kuc]

it does seem like an issue with reactor step verifier

[Dariusz Kuc]

to complete the thread -> so the issue was that step verifier attempts to verify the context on the result of the filter mono chain. Since final value is not yet computed there is nothing yet added to the context so the StepVerifier checks against the context will fail.

Unit test fix was to manually capture the context in the reactor chain and then complete it before attempting to verify the context (https://github.com/ExpediaGroup/graphql-kotlin/pull/361/commits/f746a886ddd97fa11dd29badecc8d7014d6fc75c)