[BUG] OneOf problem

[devhl-labs]

Please see this branch which illustrates the problem. https://github.com/devhl-labs/openapi-generator/tree/one-of-issue

The issue is that oneOf options are treated inconsistently.

public BillingInvoiceCustomer(CustomerId? customerId, string customerId, string name)

Here you can see one of the oneOf options is being wrapped in it's own class of CustomerId. But then the other option is not wrapped in it's own class. I would expect it to be more like this

public BillingInvoiceCustomer(CustomerId customerId)
public BillingInvoiceCustomer(CustomerDetails customerDetails)

[devhl-labs]

Taking another look, I see that CustomerDetails does exist but the properties of that class are also in the model's codegen collections.

The yaml in question is openapi-generator\bin\configs\csharp-netcore-OpenAPIClient-generichost-netcore5.0-nrt.yaml
But append this yaml to the spec

    CustomerId:
      type: object
      properties:
        customerId:
          type: string
    CustomerDetails:
      type: object
      properties:
        customerId:
          type: string
        name:
          type: string
    BillingInvoice:
      type: object
      properties:
        billingId:
          type: string
        customer:
          oneOf:
            - $ref: '#/components/schemas/CustomerId'
            - $ref: '#/components/schemas/CustomerDetails'

[JMLX42]

I think the Rust generator exhibits the exact same problem:

      "MaterialPbrMetallicRoughnessResourceSparseRelationshipsObject": {
        "type": "object",
        "properties": {
          "baseColorTexture": {
            "oneOf": [
              {
                "type": "null"
              },
              {
                "$ref": "#/components/schemas/TextureInfoResourceRelationshipToOne"
              }
            ]
          },
          "metallicRoughnessTexture": {
            "oneOf": [
              {
                "type": "null"
              },
              {
                "$ref": "#/components/schemas/TextureInfoResourceRelationshipToOne"
              }
            ]
          }
        }
      },

generates:

#[derive(Clone, Default, Debug, PartialEq, Serialize, Deserialize)]
pub struct MaterialPbrMetallicRoughnessResourceSparseRelationshipsObject {
    #[serde(rename = "baseColorTexture", default, with = "::serde_with::rust::double_option", skip_serializing_if = "Option::is_none")]
    pub base_color_texture: Option<Option<models::TextureInfoResourceRelationshipToOne>>,
    #[serde(rename = "metallicRoughnessTexture", default, with = "::serde_with::rust::double_option", skip_serializing_if = "Option::is_none")]
    pub metallic_roughness_texture: Option<Option<models::MaterialPbrMetallicRoughnessResourceSparseRelationshipsObjectMetallicRoughnessTexture>>,
}

instead of:

#[derive(Clone, Default, Debug, PartialEq, Serialize, Deserialize)]
pub struct MaterialPbrMetallicRoughnessResourceSparseRelationshipsObject {
    #[serde(rename = "baseColorTexture", default, with = "::serde_with::rust::double_option", skip_serializing_if = "Option::is_none")]
    pub base_color_texture: Option<Option<models::TextureInfoResourceRelationshipToOne>>,
    #[serde(rename = "metallicRoughnessTexture", default, with = "::serde_with::rust::double_option", skip_serializing_if = "Option::is_none")]
    pub metallic_roughness_texture: Option<Option<models::TextureInfoResourceRelationshipToOne>>,
}

[JMLX42]

Might be related: #9834

[JMLX42]

Fixed in 7.13.0 by #21043