[BUG][kotlin-server] Kotlin Server Generator Does Not Support UUID

[luisvt]

Bug Report Checklist

• Have you provided a full/minimal spec to reproduce the issue?
• Have you validated the input using an OpenAPI validator?
• Have you tested with the latest master to confirm the issue still exists?
• Have you searched for related issues/PRs?
• What's the actual output vs expected output?
• [Optional] Sponsorship to speed up the bug fix or feature request (example)

Description

When having next spec:

definitions:
  UuidTest:
    type: object
    required:
      - uuidReq
    properties:
      uuidReq:
        type: string
        format: uuid
        example: 72f98069-206d-4f12-9f12-3d1e525a8e84
      uuidNoReq:
        type: string
        format: uuid
        example: 72f98069-206d-4f12-9f12-3d1e525a8e84

the generator generates next code:

@Serializable
data class UuidTest(
  val uuidReq: UUID,
  var uuidNoReq: UUID,
)

which causes next compilation error after running gradle assemble:

Details: kotlinx.serialization compiler plugin internal error: unable to transform declaration, see cause
...
Caused by: java.lang.IllegalStateException: Serializer for element of type java.util.UUID? has not been found
	at org.jetbrains.kotlinx.serialization.compiler.backend.ir.SerializerSearchUtilKt.findTypeSerializerOrContext(SerializerSearchUtil.kt:84)

To solve this issue is it should generate next kotlin code with the annotation @Contextual from kotlinx.serialization package:

@Serializable
data class UuidTest(
  @Contextual
  val uuidReq: UUID,
  @Contextual
  var uuidNoReq: UUID,
)

openapi-generator version

7.4.0

Generation Details

openapi-generator generate -i uuid-test.yaml -g kotlin-server

Suggest a fix

[Chrimle]

Hi @luisvt thanks for the bug report!

Could you clarify what the issue is?
What you expect vs what you get

Thanks! 😊

[luisvt]

@Chrimle I just updated the description