Generation of schema that references outside schema

[oondaasta]

Description

Generation of a schema, that references other schemas in the $ref results in a invalid schema.ts, with "unkown" types and wrong property referencing Property 'Problem' does not exist on type 'unknown'

Name	Version
openapi-typescript	6.2.4
Node.js	20.1.0
OS + version	macOS 13, Windows 11, etc.

Reproduction

Run following code as a .yml in the generator:

openapi: 3.0.0
servers:
  - url: https://dummy.to.server/v1
info:
  description: Test YAML
  version: 0.1.0
  title: Test
  termsOfService: ''
security:
  - bearerAuth: [ ]
tags:
  - name: Test Object
    description: Basic operations on a test object
paths:
  /test-object/{uuid}:
    get:
      summary: Returns a test object
      tags:
        - Test Object
      description: Returns a single test object if exists
      parameters:
        - name: uuid
          in: path
          required: true
          schema:
            type: string
      operationId: getLatestTOByUUID
      responses:
        '200':
          description: Test Object
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/TestObject'
        '404':
          description: Test Object not found
          content:
            application/problem+json:
              schema:
                $ref: 'https://opensource.zalando.com/restful-api-guidelines/models/problem-1.0.0.yaml#/Problem'
        default:
          description: Unexpected error
          content:
            application/problem+json:
              schema:
                $ref: 'https://opensource.zalando.com/restful-api-guidelines/models/problem-1.0.0.yaml#/Problem'
components:
  schemas:
    TestObject:
      type: object
      properties:
        uuid:
          type: string
        id:
          type: integer
  securitySchemes:
    bearerAuth:
      type: http
      scheme: bearer
      bearerFormat: JWT

How can this be reproduced / when did the error occur?

Generate a schema based on the prior .yml file.

Expected result

(in case it’s not obvious)

Checklist

• My OpenAPI schema passes the Redocly validator (npx @redocly/cli@latest lint)

[drwpow]

This seems like a definite bug. Thank you for the thorough reproduction! 🙏 That helps immensely in diagnosing the problem.

[mitchell-merry]

The issue here is that the external schema looks like:

Problem:
  type: object
  properties:
    type:
      type: string
      format: uri
      description: |
        An absolute URI that identifies the problem type.  When dereferenced,
        it SHOULD provide human-readable documentation for the problem type
        (e.g., using HTML).
      default: 'about:blank'
      example: 'https://zalando.github.io/problem/constraint-violation'
    title:
      type: string
      description: |
        A short, summary of the problem type. Written in english and readable
        for engineers (usually not suited for non technical stakeholders and
        not localized); example: Service Unavailable
    status:
      type: integer
      format: int32
      description: |
        The HTTP status code generated by the origin server for this occurrence
        of the problem.
      minimum: 100
      maximum: 600
      exclusiveMaximum: true
      example: 503
    detail:
      type: string
      description: |
        A human readable explanation specific to this occurrence of the
        problem.
      example: Connection to database timed out
    instance:
      type: string
      format: uri
      description: |
        An absolute URI that identifies the specific occurrence of the problem.
        It may or may not yield further information if dereferenced.

Even though the $ref specifies Problem in the example:

$ref: 'https://opensource.zalando.com/restful-api-guidelines/models/problem-1.0.0.yaml#/Problem'

the subschema is being read as

{
  "hint": "SchemaObject",
  "schema": {
    "Problem": {
      "type": "object",
      "properties": { ... }
    }
  }
}

instead of

{
  "hint": "SchemaObject",
  "schema": {
    "type": "object",
    "properties": { ... }
  }
}

(So in this case, not a SchemaObject, but one level above, the Map<string, SchemaObject>)