[BUG] [scala-http4s] Enum names lose underscores due to camelCase conversion

[theresa-fun]

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

The EnumEntryLambda inner class in
ScalaHttp4sClientCodegen.java (line ~628)
calls formatIdentifier(fragment, true) on enum entry values. This delegates to AbstractScalaCodegen.formatIdentifier() which runs camelize() — stripping all underscores.

So an enum value like ACTIVE_STATUS becomes ACTIVESTATUS in the generated Scala code, which is incorrect — ACTIVE_STATUS is a perfectly valid Scala identifier and should be preserved as-is.

openapi-generator version

7.13.0

OpenAPI declaration file content or url

openapi: "3.0.3"
info:
  title: Test
  version: "1.0"
paths: {}
components:
  schemas:
    MyStatus:
      required:
        - status
      type: object
      additionalProperties: false
      properties:
        status:
         description: current status
        enum:
          - ACTIVE_STATUS
          - INACTIVE_STATUS
        type: string

Generation Details

openapi-generator-cli generate \
  -g scala-http4s \
  -i spec.yaml \
  -o output/
  --global-property models

Steps to reproduce

1. Generate code with the spec above using scala-http4s generator
2. Look at the generated enum values — ACTIVE_STATUS becomes ACTIVESTATUS, INACTIVE_STATUS becomes INACTIVESTATUS

Expected: ACTIVE_STATUS stays ACTIVE_STATUS .

Actual: All enum values are run through camelize(), which strips underscores.

Related issues/PRs

• did not find any

Suggest a fix

In ScalaHttp4sClientCodegen.java, change EnumEntryLambda.formatFragment() to preserve valid identifiers and only backtick-escape invalid ones:

private class EnumEntryLambda extends CustomLambda {
    @Override
    public String formatFragment(String fragment) {
        if (fragment.matches("^[A-Za-z_][A-Za-z0-9_]*$") && !isReservedWord(fragment)) {
            return fragment;
        }
        return "`" + fragment + "`";
    }
}