[Kotlin] Make ApiClient in jvm-retrofit2 be able to add additional retrofit Converter.Factory

[shanselm-ergon]

Description

In our project we use the openapi-generator 5.0.0-beta2 for generating our kotlin client stubs. The ApiClient offers some constructor parameters but I'm missing an option to add an additional retrofit Converter.Factory. I need this option to specify a factory, which serializes a date object as query parameter string (in our custom format, .toString() is not enough for me). In our project we use GSON as serialization library and I couldn't figure out how it is possible to set such a retrofit converter for query parameters with the currently available options.

For testing purposes I extended the generated ApiClient class with an additional constructor parameter to add our specific Converter.Factory and with this change the query parameter could successfully be serialized.

Is there already a possibility to achieve my requested behaviour with the SerializerBuilder I can pass into the class? Or is there a different approach to achieve this? What is your opinion to my described workaround?

Thank you

openapi-generator version

5.0.0-beta2

Suggest a fix/enhancement

Add an option (constructor param) to add custom retrofit converter factories. This should be optional and not break current clients.
I could create a pull request with a possible change if you wish.

[shanselm-ergon]

Resolved with [#9316 ]