[BUG][KOTLIN] kotlin-server generator bug that skips imports for enum classes in Paths.kt file

Created by: svok

Bug Report Checklist

Have you provided a full/minimal spec to reproduce the issue?
Have you validated the input using an OpenAPI validator (example)?
What's the version of OpenAPI Generator used?
Have you search for related issues/PRs?
What's the actual output vs expected output?
[Optional] Bounty to sponsor the fix (example)

Description

The full sample project is published in https://github.com/svok/openapi-test The bug concerns kotlin-server (KTOR) generator. The main bug consequence is a lucking import declaration for the enum class in the Paths.kt file that causes Unresolved reference: SomeStatus error message.

openapi-generator version

4.2.3

OpenAPI declaration file content or url

Full declaration is over there: https://github.com/svok/openapi-test/blob/master/spec.yaml

The code causing error is following:

  /pet/findByStatus:
    get:
      tags:
        - pet
      parameters:
        - name: status
          in: query
          schema:
            type: array
            items:
              $ref: '#/components/schemas/SomeStatus'
components:
  schemas:

    SomeStatus:
      type: string
      default: available
      enum:
        - available
        - pending
        - sold

Command line used for generation

The complete set of the parameters can be foun in the generateKotlinModels task of the https://github.com/svok/openapi-test/blob/master/build.gradle.kts file.

Steps to reproduce

To reproduce the error you need to start:

./gradlew generateKotlinModels

After that you can find in Paths.kt file:

    @KtorExperimentalLocationsAPI
    @Location("/pet/findByStatus") class findPetsByStatus(val status: kotlin.Array<SomeStatus>)

where SomeStatus is undeclared

The extra lines to be included into the file:

import org.example.rest.models.SomeStatus

NOTE! The same declaration in kotlin/org/example/rest/models/Pet.kt contains import for SomeStatus, but there it is not required.

Related issues/PRs

Not found

Suggest a fix

Right now I have no idea. The bug may relate to the following file: https://github.com/OpenAPITools/openapi-generator/blob/master/modules/openapi-generator/src/main/resources/kotlin-server/libraries/ktor/Paths.kt.mustache