factory2.ts

interface StoreOptions {

}

interface DbStoreOptions extends StoreOptions {
  dsn: string
}

interface FileStoreOptions extends DbStoreOptions {
  path: string
}

interface IStore {
  get(): void;
}

class DbStore implements IStore {
  constructor(options: DbStoreOptions) { }
  get() {
    console.log("beep beep");
  }
}
class FileStore implements IStore {
  constructor(options: FileStoreOptions) { }
  get() {
    console.log("tick tock");
  }
}





function factory(storeName: string, storeOptions: StoreOptions): IStore {
  const storeMap: {
    [index: string]: any
  } = { file: FileStore, db: DbStore }
  return new storeMap[storeName](storeOptions)
}

const store = factory('file', { path: 'test' })
store.get()