[REQ][Kotlin] Use Moshi codegen instead of reflection for generating JSON adapters

Is your feature request related to a problem? Please describe.

Moshi can generate JSON adapters two different ways. The old way used reflection. There is a newer way that avoids reflection and uses code generation instead. Typically, code generation performs better than reflection.

OpenAPI uses the reflection approach when generating Kotlin Moshi code.

Describe the solution you’d like

Ideally, OpenAPI Generator would use the code generation approach over reflection.

Remove com.squareup.moshi:moshi-kotlin dependency. Remove Moshi.Builder().add(KotlinJsonAdapterFactory()) Add com.squareup.moshi:moshi-kotlin-codegen dependency. Annotate each generated model with @JsonClass(generateAdapter = true)

Describe alternatives you’ve considered

The alternative is leaving it as is, but that may affect performance.

Additional context

See: https://github.com/square/moshi#kotlin

[alexfacciorusso]

Hi all!

I think the moshiCodeGen : true option is not listed anywhere, and it should be added to the doc!

[stephen-mojo]

And closing again. Sorry about the back and forth! Once again, I spoke before thinking hard enough.

My issue was that I had the following dependency… implementation "com.squareup.moshi:moshi-kotlin-codegen:$moshi_version"

…when I should have had this: kapt "com.squareup.moshi:moshi-kotlin-codegen:$moshi_version"

Thanks again for your help!