Support for non-nullable types in Kotlin

NB: This is a more specific continuation of issue #269

When generating apidocs from Kotlin data classes the non-nullable fields are not listed as required.

data class Person(
    val name: String
    val nickname: String?
)

The name property should be in the required list:

"Person": {
        "required": [
          "name"
        ],
...

There are workarounds like annotating the non-nullable properties with javax.validation.NotNull, but that is too verbose to my taste.

[fveerden]

Hi @bnasslahsen ,

It seems to work for function parameters, but not on the response data classes in the components.schemas section of the openapi document. Can you reopen the issue?

Kind regards, Frank.

[lsuski]

It seems that it does not work for request body parameters and responses wrapped with ResponseEntity