http-client.ts

export interface IHTTPClient {
   request(requset: Request): Promise<Response>
}
     
export class HTTPClient implements IHTTPClient {
  private _fetch: window['fetch']
     
  constructor(
     fetch: window['fetch']
  ) {
    this._fetch = fetch   
  }     
     
  request(requset: Request): Promise<Response> {
    return this._fetch(request)
  }
}

minimal-http-cleint.ts

export interface IHTTPClient {
   fetch(requset: Request): Promise<Response>
}