[BUG][RUBY] Integer default enum value references constant that does not exist

Bug Report Checklist

• Have you provided a full/minimal spec to reproduce the issue?
• Have you validated the input using an OpenAPI validator (example)?
• 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

Generating code for ruby with an integer enum with a default references a constant that does not exist for the default value. See example

openapi-generator version

openapi-generator-cli 7.2.0-SNAPSHOT commit : 46dd875 (docker)

OpenAPI declaration file content or url

{
  "openapi": "3.0.3",
  "info": {
    "title": "Sample API",
    "version": "1.0.0"
  },
  "paths": {},
  "components": {
    "schemas": {
      "ExampleObject": {
        "type": "object",
        "properties": {
          "state": {
            "type": "integer",
            "enum": [
              128,
              2
            ],
            "default": 128,
            "description": "The state of the object."
} } } } } }

Generation Details

❯ mkdir config
❯ touch config/dummy.json
# paste the definition into dummy.json
❯ docker run --rm \
                                             -v "$(PWD)/config/:/local" \
                                             -v "$(PWD):/out" \
                                            --pull always \
                                             openapitools/openapi-generator-cli generate \
                                               --skip-validate-spec \
                                               --generator-name ruby --output /out \
                                               --input-spec /local/dummy.json \
                                               --additional-properties gemName=dummy

Steps to reproduce

In the generated code, search for STATE::N128. There is no declaration for this constant. The N128 seems to come from the default 128. Example:

# lib/probely/models/example_object.rb

      if attributes.key?(:'state') 
        self.state = attributes[:'state']
      else
        self.state = STATE::N1 # Line 86
      end

Related issues/PRs

This looks very similar to https://github.com/OpenAPITools/openapi-generator/issues/16455 but for Ruby. I have tested with the latest version and it's still happening for Ruby

Suggest a fix

If the property is a string, it references the value directly, rather than a constant:

      if attributes.key?(:'state')
        self.state = attributes[:'state']
      else
        self.state = 'active'
      end

Start with the generated lib/probely/models/example_object.rb shown in the report and reproduce the issue using the provided OpenAPI JSON and Docker command. Trace how the Ruby generator handles an integer enum default compared with a string default. Done means the generated default refers to a declared value or otherwise produces valid Ruby without an undefined STATE::N128 constant.