$withUpdateableProperties does not make updatable properties optional. Which either it or the openapi3 emitter should.

[johanste]

import "@cadl-lang/rest";

model Something {
  @key
  id: string;

  thisIsUpdatable: string;
}

@Cadl.Http.post op stuff(properties: UpdateableProperties<Something>): Something;

=>

"schemas": {
      "UpdateableProperties_Something": {
        "type": "object",
        "properties": {
          "id": {
            "type": "string"
          },
          "thisIsUpdatable": {
            "type": "string"
          }
        },
        "description": "The template for adding updateable properties.",
        "required": [
          "id",
          "thisIsUpdatable" // <-- this should not be required
        ]

Playground Link

[markcowl]

There is a separate template for optional properties. This gets used in patch bodies for ARM: https://github.com/Azure/cadl-azure/blob/main/packages/cadl-azure-resource-manager/lib/arm.cadl#L92

[markcowl]

@johanste can we close this?