Union intermediate types don't include the variant name

[MJDSys]

Expected Behavior

I'm trying to generate a Union enumeration where some of the variants use the same type for their contents. In this case, the enumeration represents a state machine where some states share the same contents. I want the states to be separate though as they represent different points in the machine. A minimal example looks like:

#[derive(Object)]
struct Details {
    pub field: i32,
}

#[derive(Union)]
#[oai(discriminator_name = "state")]
#[oai(one_of)]
enum State {
    Variant1(Details),
    Variant2(Details),
}

Ideally the generated OpenAPI definition would still fully distinguish between these states.

Actual Behavior

The actual generated schema generates one type for both variants, which makes them indistinguishable and not a valid oneOf OpenAPI type. The generated schema looks like:

components:
  schemas:
    Details:
      type: object
      title: Details
      required:
      - field
      properties:
        field:
          type: integer
          format: int32
    State:
      type: object
      oneOf:
      - $ref: '#/components/schemas/State_Details'
      - $ref: '#/components/schemas/State_Details'
      discriminator:
        propertyName: state
        mapping:
          Variant1: '#/components/schemas/State_Details'
          Variant2: '#/components/schemas/State_Details'
    State_Details:
      allOf:
      - type: object
        required:
        - state
        properties:
          state:
            type: string
            enum:
            - Variant2
            example: Variant2
      - $ref: '#/components/schemas/Details'

Steps to Reproduce the Problem

I've created a full sample here: https://github.com/MJDSys/poem-repo

The issue seems to be here:

poem/poem-openapi-derive/src/union.rs

Line 83 in db58a4a

::std::format!("{}_{}", <Self as #crate_name::types::Type>::name(), <#object_ty as #crate_name::types::Type>::name())

Where the schema name is generated based on the type of the interior struct. If it is an acceptable change, I could submit a PR changing this to be based on the variant's name in the enumeration which would be unique.

Specifications

• Version: 5.1.14
• Platform: Linux
• Subsystem: poem-openapi

[attila-lin]

Feel free to make a pr if it works for you~