CSharp Code Generation: GenerateOptionalPropertiesAsNullable is not respected for OAS Schema Components

[Jesse0451]

Related to RicoSuter/NSwag#2313

Optional Scalar properties do not produce nullable C# built-in value types when the types are defined in components/schema.

openapi: '3.0.2'
info:
  title: API Title
  version: '1.0'
servers:
  - url: https://api.server.test/v1
paths:
  /test:
    post:
      requestBody:
        required: true
        content: 
         application/json:
            schema: 
              type: object
              properties:
                requiredInlineNumber:
                  type: integer
                  minimum: 1
                optionalInlineNumber:
                  type: integer
                  minimum: 1
                requiredSchemaNumber: 
                    $ref: "#/components/schemas/naturalNumber"
                optionalSchemaNumber: 
                    $ref: "#/components/schemas/naturalNumber"
              required: 
                - requiredInlineNumber
                - requiredSchemaNumber
              additionalProperties: false
      responses:
        '200':
          description: OK
components:
  schemas:      
    naturalNumber:
      type: integer
      minimum: 1

Generated C# class:

    public partial class Body 
    {
        [Newtonsoft.Json.JsonProperty("requiredInlineNumber", Required = Newtonsoft.Json.Required.Always)]
        [System.ComponentModel.DataAnnotations.Range(1, int.MaxValue)]
        public int RequiredInlineNumber { get; set; }
    
        [Newtonsoft.Json.JsonProperty("optionalInlineNumber", Required = Newtonsoft.Json.Required.DisallowNull, NullValueHandling = Newtonsoft.Json.NullValueHandling.Ignore)]
        [System.ComponentModel.DataAnnotations.Range(1, int.MaxValue)]
        public int? OptionalInlineNumber { get; set; }
    
        [Newtonsoft.Json.JsonProperty("requiredSchemaNumber", Required = Newtonsoft.Json.Required.Always)]
        [System.ComponentModel.DataAnnotations.Range(1, int.MaxValue)]
        public int RequiredSchemaNumber { get; set; }
    
        [Newtonsoft.Json.JsonProperty("optionalSchemaNumber", Required = Newtonsoft.Json.Required.DisallowNull, NullValueHandling = Newtonsoft.Json.NullValueHandling.Ignore)]
        [System.ComponentModel.DataAnnotations.Range(1, int.MaxValue)]
        public int OptionalSchemaNumber { get; set; }
    
    
    }

When GenerateOptionalPropertiesAsNullable is true, OptionalSchemaNumber is expected to be nullable (int?) as per OptionalInlineNumber.

[RicoSuter]

Touching nullability is very dangerous as it could break other things.. can you create a PR with a unit test reproducing this here (with a JSOn Schema)?

[tjmcdonough]

Is it possible to also GenerateOptionalPropertiesAsNullable when required is false? I am using an Open API schema where required is false but they haven't specified if the schema.nullable is true

[RicoSuter]

Might be fixed with the next version of NJS/NSwag.