Openapi-generator: [BUG] [Dart] Generated code does not support model of array of objects

[markathomas]

Bug Report Checklist

• [X] Have you provided a full/minimal spec to reproduce the issue?
• [X] Have you validated the input using an OpenAPI validator (example)?
• [X] What's the version of OpenAPI Generator used? 3.0.0
• [X] Have you search for related issues/PRs?
• [X] What's the actual output vs expected output?

Description

I have an API that returns a JSON array of objects modeled in the attached spec. The generated code has both a ListOfMessage object and a Message object but the ListOfMessage object has no fields.

openapi-generator version

3.0.0

OpenAPI declaration file content or url

openapi: 3.0.0
info:
  description: Chat API
  version: "1.0.0-oas3"
  title: Chat API
  contact:
    email: [email protected]
  license:
    name: Apache 2.0
    url: 'http://www.apache.org/licenses/LICENSE-2.0.html'
tags:
  - name: admins
    description: Secured Admin-only calls
  - name: developers
    description: Operations available to regular developers
paths:
  '/api/v1/chat/{acctNum}/room/{id}/messages':
    get:
      tags:
        - developers
      summary: searches for messages by room
      operationId: messagesByRoomV1
      parameters:
        - in: path
          name: acctNum
          description: Account number of organization
          required: true
          schema:
            type: string
        - in: path
          name: id
          description: Chat room id
          required: true
          schema:
            type: integer
      responses:
        '200':
          description: search results matching criteria
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/ListOfMessage'
        '400':
          description: bad input parameter
        '403':
          description: >-
            forbidden if account number does not match user organization account
            number and user is not a super-admin
        '500':
          description: internal server error
servers:
  - url: 'https://test.fake.io'
components:
  schemas:
    ListOfMessage:
      type: array
      items:
        $ref: '#/components/schemas/Message'
    Message:
      required:
        - id
        - createdOn
        - updatedOn
        - owner
        - ownerName
        - content
        - chatRoomId
      properties:
        id:
          type: integer
        createdOn:
          type: integer
        updatedOn:
          type: integer
        owner:
          type: integer
        ownerName:
          type: string
        content:
          type: string
        chatRoomId:
          type: integer

Suggest a fix

The generated code could simply return a Dart list of Message or a a list of Message could be added to the ListOfMessage class. It seems the generator does not support components of type array in this language.

A workaround is to change the ListOfMessage definition to the following:

ListOfMessage:
      required:
        - messages
      properties:
        messages:
          type: array
          items:
            $ref: '#/components/schemas/Message'

however, I was only able to do this because I control the API.

[wing328]

Instead of using/defining ListOfMessage, what about defining the content as the following instead?

          content:
            application/json:
              schema:
                type: array
                items:
                  $ref: '#/components/schemas/Message'

[markathomas]

Thanks @wing328 that worked!

[wing328]

No problem. Glad to help out.

[artellan]

@wing328 I don't believe this bug should have been closed. Following the thread above, it seems that you closed it because the workaround worked, but it requires control over the api spec. If you don't have control over the spec, you cannot apply the workaround.