[BUG] [typescript-axios] Models not generated for multipart/form-data request

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?
• [Optional] Sponsorship to speed up the bug fix or feature request (example)

Description

The typescript-axios (client) code generator does not generate model classes for multipart/form-data requests.

openapi-generator version

5.4.0

OpenAPI declaration file content or url

https://gist.github.com/cyberflohr/1961192f24060b9bbd05a649f5245c5f

Generation Details

npx openapi-generator-cli generate -g typescript-axios -i openapi.json -o .

Steps to reproduce

After the generation step, search the generated files for the desired model classes.

grep -e TemplateCreate -e AreaAttribute *

The grep command does not list any classes for TemplateCreate and AreaAttribute

api.ts:     * @type {Array<AreaAttribute>}
api.ts:    'attributes': Array<AreaAttribute>;
openapi.json:                "$ref": "#/components/schemas/TemplateCreate"
openapi.json:      "AreaAttribute": {
openapi.json:              "$ref": "#/components/schemas/AreaAttribute"
openapi.json:      "TemplateCreate": {

Changing the request from "multipart/form-data" to "application/json" and re-generate the classes again will list the missing classes -> IMO a bug in combination with "multipart/form-data".

Related issues/PRs

Suggest a fix

Start by generating the typescript-axios client from the linked OpenAPI declaration with the shown command, then inspect api.ts and the generated files for TemplateCreate and AreaAttribute. Compare the multipart/form-data result with the application/json result; done means both models are generated and referenced correctly for the multipart request.