encodedName does not apply to discriminator

[xiangyan99]

I have such code in tsp file https://github.com/Azure/azure-rest-api-specs/blob/6835b53e2d8ba8a41fcf88b1eae56d4ad44ff9fb/specification/search/Azure.Search/models-service.tsp#L6202-L6214:

/**
 * Base type for character filters.
 */
@discriminator("odataType")
model CharFilter {
  /** The discriminator for derived types. */
  #suppress "@azure-tools/typespec-azure-core/no-string-discriminator" "Existing"
  @encodedName("application/json", "@odata.type")
  odataType: string;

  /**
   * The name of the char filter. It must only contain letters, digits, spaces,
   * dashes or underscores, can only start and end with alphanumeric characters, and
   * is limited to 128 characters.
   */
  name: string;
}

I expected odataType can be renamed into @odata.type, including the one in the discriminator.

But the generated openapi.json https://github.com/Azure/azure-rest-api-specs/blob/6835b53e2d8ba8a41fcf88b1eae56d4ad44ff9fb/specification/search/data-plane/Search/stable/2024-07-01/openapi.json#L2899-L2918 only has

"CharFilter": {
      "type": "object",
      "description": "Base type for character filters.",
      "properties": {
        "@odata.type": {
          "type": "string",
          "description": "The discriminator for derived types.",
          "x-ms-client-name": "odataType"
        },
        "name": {
          "type": "string",
          "description": "The name of the char filter. It must only contain letters, digits, spaces,\ndashes or underscores, can only start and end with alphanumeric characters, and\nis limited to 128 characters."
        }
      },
      "discriminator": "odataType",
      "required": [
        "@odata.type",
        "name"
      ]
    },

It still uses "discriminator": "odataType".

The entire project can be found at https://github.com/Azure/azure-rest-api-specs/tree/search_tsp/specification/search/Azure.Search

[iscai-msft]

@xiangyan99 since this is an openapi emitter issue, you should open this issue in the TypeSpec repo. I also confirmed this isn't an issue on the python emitter, we're generating with wire name @odata.type. Would you be ok if I transferred this to the typespec repo?