Question on declaring @anyOf on Named Unions

[Devon (Devon-White)]

I'm finding that declaring a Named Union with the @oneOf decorator doesn't seem to enforce anyOf becoming oneOf is the spec file when used as a value in a Model.

I also tried decorating the property in the Model that accepts the Named Union as the value with oneOf, same behavior.

Example can be found here

However, removing the Name Union and using a Union Expression inside the model, will allow it to generate with oneOf.

Example can be found here

Should the first example work?

[Timothee Guerin (timotheeguerin)]

I think in the first case it might be a confusion in the syntax that result in not exactly what you expect

In named union the variants are separated with comma ,. What you have is a union of model A and B inside that named union. So when openapi3 sees it, it sees a union with a single variant A | B so just ignore anyOf or oneOf and just render the single variant which happens to be a union which is then not annotated with @oneOf

See this playground showing the difference