springdoc-openapi:generate does not respect @field:Schema(enumAsRef = true) on a kotlin data class property

[damiankaplon]

Good morning, evening!

Having

@RestController
class HelloController {

	@GetMapping("/hello")
	fun hello() = Response(status = Response.Status.SUCCESS)
}

data class Response(@field:Schema(enumAsRef = true) val status: Status) {
	enum class Status {
		SUCCESS,
		ERROR
	}
}

generates response schema ⬇ :

"schemas":{"Response":{"type":"object","properties":{"status":{"type":"string","enum":["SUCCESS","ERROR"]}}}}

I expected ⬇ :

"schemas":{"Response":{"type":"object","properties":{"status":{"$ref":"#/components/schemas/Status"}}},"Status":{"type":"string","enum":["SUCCESS","ERROR"]}}}

It can be achieved annotating an enum class with Schema(enumAsRef = true) but I'd prefer to annotate a data class property instead) 🙏🏼

Here is a minimal, reproducible example

Versions:

                         <groupId>org.springframework.boot</groupId>
		        <artifactId>spring-boot-starter-parent</artifactId>
		        <version>3.5.0</version>

			<groupId>org.springdoc</groupId>
			<artifactId>springdoc-openapi-starter-webmvc-api</artifactId>
			<version>2.8.0</version>

			<groupId>org.springdoc</groupId>
			<artifactId>springdoc-openapi-starter-common</artifactId>
			<version>2.8.0</version>

	                 <groupId>org.springdoc</groupId>
			<artifactId>springdoc-openapi-maven-plugin</artifactId>
			<version>1.4</version>