[BUG][RUBY and others] Default parameters should not be added in code generation

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

Reading about parameters, the default is:

The default value is the one that the server uses if the client does not supply the parameter value in the request

As I understand, this means that default does not have to be added by the client. However, code generation adds the default value to the request. I would expect that this is not added by the client. I believe this is not specific to Ruby (the one I tried this with)

openapi-generator version

openapi-generator-cli 7.2.0-SNAPSHOT
commit : 46dd875

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": "string",
            "enum": [
              "foo",
              "bar"
            ],
            "default": "foo",
            "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

# lib/probely/models/example_object.rb

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

I think this else should not be there

Related issues/PRs

There was this old discussion here

Suggest a fix

In the description

Start with the reproduced output in lib/probely/models/example_object.rb and rerun the documented Docker command using the Ruby generator and dummy.json. Compare the generated handling of the state default with the issue's expected behavior; done means the client does not add the schema default when the parameter was not supplied, consistently across the affected generators.