Internally Tagged Enum Definitions

[RXminuS]

Hey I'm trying to generate typescript types from the generated JSON schema and am running into a bit of a design constraint.

Basically the generated type for an enum that has [#serde(tag="...")] gets turned into an anyOf where the resulting types are directly mentioned without them being given a definition. This is in contrast from for instance using [#serde(tag="t", content="c")] where a new definition is inserted for every type of content.

When generating Typescript the latter is much more convenient since you get a discriminated union where you can still refer to each individual item since they will be named. In contrast the former just gives a giant union blob where it's hard to do things like casting to a specific type.

I would like to figure out a way we can make the JSON schema more verbose and essentially generate definitions for every enum item. Happy to make a PR if someone can point me in the right direction of where to find the relevant code bits.

[jetuk]

@RXminuS did you ever resolve this query?

[Tails]

@GREsau what would the difficulty of implementing this be? If we have a checklist here we could work on it in a PR.

• [x] create test based on internally tagged enum to include discriminator
• [ ] add 'discriminator' option to OpenAPI schema settings definition to enable/disable generation of property
• [x] find out where parsed serde attributes are stored / used -> expr_for_internal_tagged_enum()#191
• [ ] make sure every instance has the 'type' property referred by the 'discriminator'
• [ ] create Visitor implementation to add this property to schema
• [ ] have Visitor set the discriminator based on whether the serde struct is tagged
• [ ] ...

See https://github.com/parture-org/schemars/tree/openapi-discriminator for WIP

[stevenliebregt]

This would be really nice to have

[tomas789]

I have done some research into this and summarized it here. It has a manual workaround to this issue. It would still be nice to have the PR finished up and merged 👍