Responses without bodies also omit headers from generated output.

[openreply-dleinhaeuser]

Description

When an OpenAPI spec does not specify a response body for a response (say 204 No Content), the generated type for that response becomes never, which omits any headers that might be specfied for that response.

Name	Version
openapi-typescript	6.2.4
Node.js	20.1.0
OS + version	macOS 13.3.1

Reproduction

Convert the following OpenAPI schema to TypeScript using openapi-typescript:

openapi: "3.0.2"
info:
  title: Response header bug example
  version: "1.0.0"
  contact:
    email: [email protected]
servers:
  - description: local server
    url: http://localhost
paths:
  "/foo":
    get:
      responses:
        "204":
          description: No Content
          headers:
            foo:
              schema:
                type: string
  "/bar":
    get:
      responses:
        "200":
          description: OK
          headers:
            "bar":
              schema:
                type: string
          content:
            "application/json":
              schema:
                type: object

Expected result

paths["/foo"]["get"]["responses"][204] is { headers: { foo?: string; } }; content: {}; } or something similar instead of never.

Checklist

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