How do I mark a field as required in a request body model?

[camille-villanueva]

Using OpenAPI 3.0.0.

Goal: I want the updated_by field to be marked as required, and the rest are optional.

What I've tried:
I have this model that defines the structure of the request payload:

model UpdateRecordRequestBody {
  ...OptionalProperties<OmitProperties<Record, "id" | "created_by" | "created_at" | "updated_at" | "updated_by">>;

  @format("uuid")
  updated_by: string;
}

However, doing it this way does not seem to work as the updated_by field is not marked as a required field in the generated OpenAPI file. Is there a way to achieve this?

[timotheeguerin]

how are you using this model? by default properties are required in typespec and this is transfered to the openapi3. Can you share a repro here https://typespec.io/playground?

[camille-villanueva]

Repro

[camille-villanueva]

@timotheeguerin If it helps, what I've observed so far is that this only seems to happen if I use a model and reference it in the op parameters. If I skip using the model, it generates the expected OpenAPI specs correctly (i.e. updated_by is listed as a required field).

// This works:

op updateCollection(
    // ...
    @body request: {
      ...OptionalProperties<OmitProperties<Collection, "id" | "created_by" | "created_at" | "updated_at" | "updated_by">>;
      
      @format("uuid")
      updated_by: string;
    };
  ) // ...;

[timotheeguerin]

ah the reason is because the operation you have is a @patch operation which right now http library makes the assumption it is a merge patch which apply if you use a model(so you can reuse the resource model)
Currently to disable that you have to put

@parameterVisibility

with no parameters on the operation playground

Please note however that this is something we are trying to change to make more explicit. @willmtemple might be able to say more