[Feature] [TYPESCRIPT] Generator parses to Array instead of Set

Bug Report Checklist

• Have you provided a full/minimal spec to reproduce the issue?
• Have you validated the input using an OpenAPI validator (example)?
• Have you tested with the latest master to confirm the issue still exists?
• Have you searched for related issues/PRs?
• What's the actual output vs expected output?

Description

If I generate a typescript-angular client with the latest 5.0 stable release, query the mentioned endpoint and try to use user.authority.has(UserAuthorityEnum.Admin) within a component I get the following error. (In Both Template/Component the Error occurs)

ERROR TypeError: _angular_core__WEBPACK_IMPORTED_MODULE_0__.ɵɵpipeBind1(...).authority.has is not a function
    at DashboardComponent_Template (main.js:2043)
    at executeTemplate (vendor.js:65785)
    at refreshView (vendor.js:65654)
    at refreshComponent (vendor.js:66801)
    at refreshChildComponents (vendor.js:65460)
    at refreshView (vendor.js:65704)
    at refreshEmbeddedViews (vendor.js:66755)
    at refreshView (vendor.js:65678)
    at refreshComponent (vendor.js:66801)
    at refreshChildComponents (vendor.js:65460)
    at refreshView (vendor.js:65704)
    at refreshEmbeddedViews (vendor.js:66755)
    at refreshView (vendor.js:65678)
    at refreshComponent (vendor.js:66801)
    at refreshChildComponents (vendor.js:65460)

With further investigation it seems like the field authority is an Array instead of a Set. I am not sure if this is a bug or if this is a result of a faulty spec. I validated with the cli validator, as well as the swagger editor and the referenced validator.
This behaviour was also present in the 5.0 beta 3 and I hoped it would be solved with the stable release.

Can anyone point me in the right direction?
If there are any more specs/configs I can help you with, don't hesitate to ask for them.

openapi-generator version

Latest stable release (5.0.0)

OpenAPI declaration file content or url

openapi: 3.0.1
info:
  title: Some Api
  description: Some Desc
  version: 0.2.0
servers:
- url: https://sample.url.com
  description: Generated server url
security:
- bearerAuth: []
paths:
  /api/users/me:
    get:
      tags:
      - user-resource
      operationId: getMe
      responses:
        "200":
          description: OK
          content:
            '*/*':
              schema:
                $ref: '#/components/schemas/User'

components:
  schemas:
    User:
      required:
      - authority
      - firstName
      - id
      - lastName
      - userStatus
      type: object
      properties:
        id:
          type: integer
          format: int64
          example: 12
        firstName:
          type: string
          example: Average
        lastName:
          type: string
          example: Joe
        phoneNumber:
          type: string
          example: "01101001001"
        userStatus:
          type: string
          example: ACTIVATED
          enum:
          - UNUSED
          - ACTIVATED
          - BLOCKED
        facilityId:
          type: integer
          format: int64
          example: 13
        authority:
          uniqueItems: true
          type: array
          example: "[CUSTODIAN]"
          items:
            type: string
            example: "[CUSTODIAN]"
            enum:
            - CUSTODIAN
            - EDUCATOR
            - FACILITY_DIRECTOR
            - SUPPORT
            - ADMIN
        childIds:
          uniqueItems: true
          type: array
          example:
          - 1
          - 2
          - 3
          items:
            type: integer
            format: int64
  securitySchemes:
    bearerAuth:
      type: http
      scheme: bearer
      bearerFormat: JWT

Generation Details

config.yaml (string enum doesn't affect thus error, I tried it with the default value as well)

snapshot: true
npmName: '@repo/api-ts-client'
npmRepository: 'https://repo-url.com/repository/npm-internal/'
stringEnums: true

Steps to reproduce

generate client

java -jar openapi-generator-cli.jar validate -i api-docs.yaml
java -jar openapi-generator-cli.jar generate -o npm-client -g typescript-angular -c config.yaml -i api-docs.yaml
cd npm-client
npm install
npm run build
npm publish dist

install it within your angular project and try to call method and try to call user.authority.has(UserAuthorityEnum.Admin) on a fetched user. You can use this json for as it is my server response

{
"id":1,
"firstName":"Admin",
"lastName":"Admin",
"phoneNumber":"01101001001",
"userStatus":"ACTIVATED",
"facilityId":null,
"authority":["ADMIN"],
"childIds":[]
}

Look in the console and look for the mentioned problem.

Related issues/PRs

I didn't find any related PR/Issues

Start with api-docs.yaml and config.yaml, then run the validate and generate commands for the typescript-angular generator. Inspect the generated authority field and compare it with the expected Set behavior shown by user.authority.has(UserAuthorityEnum.Admin); done means the reported usage works or the specification limitation is clearly established.