@joeytwiddle thank you for opening this pull request. The proposed changes are going in the right direction, but I am don't think we have the required underlying block already in place.

-    @requestBody() data: Todo,
+    @requestBody() data: Partial<Todo>,

The way how @requestBody() currently works: it's using the so-called design:type metadata produced by TypeScript to learn about the type of the argument value (a Todo constructor). When this design:type is a model, then the decorator emits a JSON/OpenAPI schema describing model properties as the accepted value.

When you change the type from Todo to Partial<Todo>, this metadata is lost and @requestBody() decorator sees only a generic object type. As a result, the OpenAPI spec describing application's REST API is describing the endpoint as accepting an empty object. At least that's what I remember - could you please check the actual behavior yourself?

If my description above still holds, then we need to find a way how to explicitly tell requestBody decorator what type is the parameter accepting, before we can change the CRUD Controller template used by our CLI. See the discussion in #1722 for implementation proposals.

Would you like to take a look at this underlying feature first?

-    @requestBody() data: Todo,
+    @requestBody() data: Partial<Todo>

As a result, the OpenAPI spec describing application's REST API is describing the endpoint as accepting an empty object. At least that's what I remember - could you please check the actual behavior yourself?

I can confirm - Partial<Todo> describes endpoint as accepting empty object.

I am closing this pull request as abandoned, feel free to reopen if you get time to work on this again.