[BUG][Kotlin] Generated Serializer for ApiClient does not support BigDecimal

[nilskuhn]

Description

Generating a Kotlin client for an API that uses BigDecimal in the model, the generated ApiClient doesn't work because the generated Moshi serializer does not have a type adapter for BigDecimal. Unfortunately, there is no way to inject the type adapter yourself.

openapi-generator version

4.3.1

Steps to reproduce

Any API with BigDecimal should demonstrate the problem. Generate Kotlin API and try to send message. I get exception:

java.lang.IllegalArgumentException: Platform class java.math.BigDecimal (with no annotations) requires explicit JsonAdapter to be registered
	at com.squareup.moshi.ClassJsonAdapter$1.create(ClassJsonAdapter.java:60) ~[moshi-1.8.0.jar:na]
	at com.squareup.moshi.Moshi.adapter(Moshi.java:137) ~[moshi-1.8.0.jar:na]

Suggest a fix

Add BigDecimal adapter here: com.kn.containerDashboard.backend.client.rgs.infrastructure.Serializer

[wing328]

@nilskuhn thanks for reporting the issue. Do you mind filing a PR with the suggested fix?

[nilskuhn]

Yes, I will try to find the time.

[zarr]

Possible workaround

Set the serializationLibrary to jackson in the generator configuration as described in https://openapi-generator.tech/docs/generators/kotlin

[kuFEAR]

Hi, I added BigDecimal/BigInteger in my fork kuFEAR@05bd4e1, I'll send it later to parent repo after merge another one pr

[codymikol]

@kuFEAR did you ever send in a PR for this?