Define type for wrapping library function-CodePudding

I’m trying to learn TypeScript but have an issue that I struggle to resolve.

function makeClient(api, kubeconfig: string) {
  const config = new k8s.KubeConfig()

  if (kubeconfig) {
    config.loadFromFile(kubeconfig)
  } else {
    config.loadFromCluster()
  }

  return config.makeApiClient(api)
}

I need to create a function that wraps another function from a library (Kubernetes client), what I want to do is to allow two arguments to my function: api and kubeconfig.
If kubeconfig is set, I will create a client for the given api argument using the given file.
If kubeconfig is not set or empty/null, I will create an in-cluster client for the given api.

My issue is that I somehow need to provide a type for the api parameter. The library provides some types, but when I look at the types of the makeApiClient function argument, I get this:

export declare class KubeConfig {
  // ...
  makeApiClient<T extends ApiType>(apiClientType: ApiConstructor<T>): T;
  // ...
}
export interface ApiType {
    defaultHeaders: any;
    setDefaultAuthentication(config: api.Authentication): void;
}
declare type ApiConstructor<T extends ApiType> = new (server: string) => T;

How should I provide a type to my api argument so that it allows only supported values?

CodePudding user response：

Why not make your wrapping function also generic? Then you can just use the type that is expected by makeAPICLient. Like this:

function makeClient<T extends k8s.ApiType>(api: k8s.ApiConstructor<T>, kubeconfig: string | null): T {
  const config = new k8s.KubeConfig()

  if (kubeconfig) {
    config.loadFromFile(kubeconfig)
  } else {
    config.loadFromCluster()
  }

  return config.makeApiClient(api)
}