[BUG][Kotlin-Spring] Query Parameter Bean Validation missing since 7.13.0

[jothepro]

Bug Report Checklist

• Have you provided a full/minimal spec to reproduce the issue?
• Have you validated the input using an OpenAPI validator?
• Have you tested with the latest master to confirm the issue still exists?
• Have you searched for related issues/PRs?
• What's the actual output vs expected output?
• [Optional] Sponsorship to speed up the bug fix or feature request (example)

Description

In 7.13.0 the bean validation in the kotlin-spring generator is missing. Apparently it was removed in this PR: https://github.com/OpenAPITools/openapi-generator/pull/20885/files#diff-31eb66768f4412e178af87d063b704a1e3a3ef250e1a69af791ec24298cea6c7

I could not find any explanation on why it was removed in the PR or the Release notes for 7.13.0.

openapi-generator version

This is a regression since 7.13.0

OpenAPI declaration file content or url

Example spec that defines a regex pattern for a query parameter:

openapi: 3.0.3
info:
  title: Sample API
  version: 1.0.0
  description: A small OpenAPI spec with one endpoint and a query parameter.
paths:
  /example:
    get:
      parameters:
        - name: queryParam
          in: query
          required: true
          schema:
            type: string
            pattern: '^[a-zA-Z0-9_-]{3,10}$'
      responses:
        '200':
          description: Successful response

Generation Details

This was executed in order to generate the code:

docker run --rm -v "${PWD}:/local" openapitools/openapi-generator-cli:latest generate \
    -i /local/spec.yaml \
    -g kotlin-spring \
    -o /local/out/kotlin-spring

According to this documentation useBeanValidation is enabled by default. No special configurations where given to the generator.

Steps to reproduce

• In v7.12.0 the kotlin-spring generator produced the following output for the /example endpoint in the openapi-spec provided above:

      @RequestMapping(
          method = [RequestMethod.GET],
          value = ["/example"]
      )
      fun exampleGet(@NotNull @Pattern(regexp="^[a-zA-Z0-9_-]{3,10}$") @Parameter(description = "", required = true) @Valid @RequestParam(value = "queryParam", required = true) queryParam: kotlin.String): ResponseEntity<Unit> {
          return ResponseEntity(HttpStatus.NOT_IMPLEMENTED)
      }

• Running the same generator on v7.13.0 or latest results in the following. The output misses the @NotNull and @Pattern validation annotations, which is unexpected because no such regression was documented in the release:

      @RequestMapping(
          method = [RequestMethod.GET],
          value = ["/example"]
      )
      fun exampleGet( @RequestParam(value = "queryParam", required = true) queryParam: kotlin.String): ResponseEntity<Unit> {
          return ResponseEntity(HttpStatus.NOT_IMPLEMENTED)
      }

The bean validation is now missing. This is also reflected in these adjustments to the testing in the Misk Kotlin Generator PR.

Related issues/PRs

• Add new Misk Kotlin OpenAPI Generator  #20885

Suggest a fix

I suggest to undo the changes from https://github.com/OpenAPITools/openapi-generator/pull/20885/files#diff-31eb66768f4412e178af87d063b704a1e3a3ef250e1a69af791ec24298cea6c7 that introduced the regression.