[string, null] definition is converted to unknown

[LarsOlt]

Description

Source:

Output:

Expected:

"image-path": string | null

Name	Version
openapi-typescript	5.4.1
Node.js	16.18.0
OS + version	Win 11

Reproduction

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

I am using the https://developers.themoviedb.org/ OAS API definition.

npx openapi-typescript https://api.stoplight.io/v1/versions/9WaNJfGpnnQ76opqe/export/oas.json --output tmdb-oas.ts

Expected result

(in case it’s not obvious)

Checklist

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

[LarsOlt]

Seems to be related to #898 ?

[drwpow]

Thank you for raising! v6 will add OpenAPI 3.1 support so will make sure this makes it in.