Unable to use allOf within an anyOf with discriminator

[dan-j]

What version of ogen are you using?

$ go list -m github.com/ogen-go/ogen

github.com/ogen-go/ogen v0.72.0

Can this issue be reproduced with the latest version?

Yes

What did you do?

Try to generate code from this schema:

openapi: 3.1.0
info:
  title: Test API
  version: 0.0.1
  license:
    name: MIT
    identifier: MIT
servers:
  - url: http://localhost:8080
paths:
  /vehicle:
    get:
      responses:
        '200':
          description: OK
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/Vehicle'
        default:
          description: Error
          content:
            application/json:
              schema: {}
components:
  schemas:
    VehicleType:
      type: string
      enum:
        - car
        - bike
    VehicleBase:
      type: object
      properties:
        id:
          type: string
        type:
          $ref: '#/components/schemas/VehicleType'
        numberOfWheels:
          type: integer
          minimum: 0
    Car:
      type: object
      allOf:
        - $ref: '#/components/schemas/VehicleBase'
        - type: object
          properties:
            type:
              const: car
            numberOfDoors:
              type: integer
              minimum: 0
    Bicycle:
      type: object
      allOf:
        - $ref: '#/components/schemas/VehicleBase'
        - type: object
          properties:
            type:
              const: bike
            bicycleType:
              type: string
              enum:
                - road
                - mountain
                - hybrid
    Vehicle:
      type: object
      discriminator:
        propertyName: type
        mapping:
          car: '#/components/schemas/Car'
          bike: '#/components/schemas/Bicycle'
      oneOf:
        - $ref: '#/components/schemas/Car'
        - $ref: '#/components/schemas/Bicycle'

What did you expect to see?

The code generate successfully

What did you see instead?

The following error output:

generate:
    main.run
        PATH_TO_PROJECT/vendor/github.com/ogen-go/ogen/cmd/ogen/main.go:304
  - build IR:
    main.generate
        PATH_TO_PROJECT/vendor/github.com/ogen-go/ogen/cmd/ogen/main.go:64
  - make ir:
    github.com/ogen-go/ogen/gen.NewGenerator
        PATH_TO_PROJECT/vendor/github.com/ogen-go/ogen/gen/generator.go:112
  - operations:
    github.com/ogen-go/ogen/gen.(*Generator).makeIR
        PATH_TO_PROJECT/vendor/github.com/ogen-go/ogen/gen/generator.go:130
  - path "/vehicle": get:
    github.com/ogen-go/ogen/gen.(*Generator).makeOps
        PATH_TO_PROJECT/vendor/github.com/ogen-go/ogen/gen/generator.go:171
  - responses:
    github.com/ogen-go/ogen/gen.(*Generator).generateOperation
        PATH_TO_PROJECT/vendor/github.com/ogen-go/ogen/gen/gen_operation.go:55
  - code 200:
    github.com/ogen-go/ogen/gen.(*Generator).generateResponses
        PATH_TO_PROJECT/vendor/github.com/ogen-go/ogen/gen/gen_responses.go:34
  - contents:
    github.com/ogen-go/ogen/gen.(*Generator).responseToIR
        PATH_TO_PROJECT/vendor/github.com/ogen-go/ogen/gen/gen_responses.go:182
  - media: "application/json":
    github.com/ogen-go/ogen/gen.(*Generator).generateContents
        PATH_TO_PROJECT/vendor/github.com/ogen-go/ogen/gen/gen_contents.go:330
  - generate schema:
    github.com/ogen-go/ogen/gen.(*Generator).generateContents.func1
        PATH_TO_PROJECT/vendor/github.com/ogen-go/ogen/gen/gen_contents.go:271
  - oneOf:
    github.com/ogen-go/ogen/gen.(*schemaGen).generate2
        PATH_TO_PROJECT/vendor/github.com/ogen-go/ogen/gen/schema_gen.go:247
  - discriminator: unable to map "car" to "file://PATH_TO_PROJECT/openapi.yaml#/components/schemas/Car":
    github.com/ogen-go/ogen/gen.(*schemaGen).oneOf
        PATH_TO_PROJECT/vendor/github.com/ogen-go/ogen/gen/schema_gen_sum.go:297

It looks like because the Car/Bicycle schema is being merged from a allOf,

ogen/gen/schema_gen_sum.go

Line 278 in eb1bcf6

if vschema == v {

is false so it never finds a mapping.

[dan-j]

Also, everything works if you omit the discriminator.mapping field, but many documentation tools use this to help the user browse the API so ideally we want to keep it in.

[dan-j]

Solved by #979