I would like to make a factory method for all my Axios Api classes (generated by OpenAPI generator).

So Open-API generates me a BaseAPI class with a constructor and dozen of Api classes extending this BaseAPI corresponding to my Backend Controllers.

So i tried that function:

import { BaseAPI } from "@/api/base";

abstract class AbstractControllerHandler {
  protected createApi<T extends typeof BaseAPI>(clazz: T)  {
    return new clazz(
      undefined,
      "",
      AxiosInstanceHolder.getInstance().getAxiosInstance(),
    );
  }

Which is used by this other class:

import { CrudCapitalsourceControllerApi } from "@/api";

class CapitalsourceControllerHandler extends AbstractControllerHandler {
  private api: CrudCapitalsourceControllerApi;

  public constructor() {
    super();

    this.api = super.createApi(CrudCapitalsourceControllerApi);
  }
}

CrudCapitalsourceControllerApi is defined as class CrudCapitalsourceControllerApi extends BaseAPI and is generated by OpenAPI.

I’m getting a ts(2739) basically stating that createApi returns type BaseAPI which cannot be assigned to a variable of type CrudCapitalsourceControllerApi.

I guess I have to specify a return type for createApi to get it to work, but T as return type does not work. It raises a ts(2322) and I don’t return a type I return an instance… so any idea of how I can fix this? I guess I would need something as “instanceof T” for the return type declaration