Incorrect enum values generated if query is optional

[frankie567]

openapi-typescript version

7.10.1

Node.js version

24.13.0

OS + version

macOS 26.2

Description

When an OpenAPI operation has all optional query parameters, the generated TypeScript types mark the query object itself as optional (query?:). However, the generated enum value constants don't account for this and try to index directly into the potentially-undefined query object.

Therefore, TypeScript complains:

output.ts:64:116 - error TS2339: Property 'status' does not exist on type '{ status?: "pending" | "active" | "completed"; } | undefined'.

export const pathsItemsGetParametersQueryStatusValues: ReadonlyArray<paths["/items"]["get"]["parameters"]["query"]["status"]> = ["pending", "active", "completed"];

Reproduction

Reproduction repository here: https://github.com/frankie567/openapi-ts-enum-repro-bug

1. Given this OpenAPI schema:

openapi: 3.1.0
info:
  title: Minimal Reproduction
  version: 1.0.0
  license:
    name: MIT
    identifier: MIT
servers:
  - url: https://api.example.org
    description: API server
security: []
paths:
  /items:
    get:
      operationId: listItems
      summary: List items with optional filters
      security: []
      parameters:
        - name: status
          in: query
          required: false
          schema:
            type: string
            enum:
              - pending
              - active
              - completed
      responses:
        "200":
          description: Success
          content:
            application/json:
              schema:
                type: array
                items:
                  type: object
        "400":
          description: Bad Request

2. Generate types with openapi-typescript:

openapi-typescript ./input.yml --enum-values -o ./output.ts

3. Run TypeScript on the output:

tsc --noEmit

Expected result

The generator should wrap the query accessor with NonNullable:

export const pathsItemsGetParametersQueryStatusValues: ReadonlyArray<
  NonNullable<paths["/items"]["get"]["parameters"]["query"]>["status"]
> = ["pending", "active", "completed"];

Allowing TypeScript to pass.

Required

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

Extra

• I’m willing to open a PR (see CONTRIBUTING.md)

[frankie567]

Duplicate of #2138