[FEATURE/BUG] Reusable Enum values / References not supported

[macjohnny]

Bug Report Checklist

• Have you provided a full/minimal spec to reproduce the issue?
• Have you validated the input using an OpenAPI validator (example)?
• What's the version of OpenAPI Generator used?
• Have you search for related issues/PRs?
• What's the actual output vs expected output?
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Description

According to swagger-api/swagger-editor#609 (comment) and OAI/OpenAPI-Specification#300 (comment) yaml files support references, which could serve to reuse e.g. enum values.
However, the following error occurs:

schemas.enum is not of type `array`

openapi-generator version

4.0.3

OpenAPI declaration file content or url

openapi: '3.0.0'
info:
  version: 1.0.0
  title: Petstore

paths:
  /pet:
    get:
      parameters:
        - $ref: '#/components/parameters/livingEnvironment'
      responses:
        '200':
          description: 'Pet'
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/Pet'
components:
  schemas:
    Pet:
      required:
        - id
        - name
      properties:
        id:
          type: integer
        name:
          type: string
        tag:
          type: string
        livingEnvironment:
          type: string
          enum: &livingEnvironmentEnum
            - Water
            - Land
            - Air

  parameters:
    livingEnvironment:
      name: livingEnvironment
      required: false
      in: query
      schema:
        type: string
        enum: *livingEnvironmentEnum

Command line used for generation

openapi-generator generate -i api-definition2.yml -g typescript-angular -o frontend-client

Steps to reproduce

Related issues/PRs

Suggest a fix

[macjohnny]

closing, as this can be solved with e.g.

openapi: '3.0.0'
info:
  version: 1.0.0
  title: Petstore
paths:
  /pets:
    get:
      parameters:
        - $ref: '#/components/parameters/livingEnvironment'
      responses:
        '200':
          description: 'An array of pets'
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/Pets'
components:
  schemas:
    LivingEnvironment:
      type: string
      enum:
        - Water
        - Land
        - Air

    Pet:
      required:
        - id
        - name
      properties:
        id:
          type: integer
        name:
          type: string
        tag:
          type: string
        livingEnvironment:
          $ref: '#/components/schemas/LivingEnvironment'
    Pets:
      type: array
      items:
        $ref: '#/components/schemas/Pet'

  parameters:
    livingEnvironment:
      name: livingEnvironment
      required: false
      in: query
      schema:
        $ref: '#/components/schemas/LivingEnvironment'

[pablo53]

I have the same issue. The bug is not resolved, this is only a workaround for the issue of not handling the enum references correctly.