URL Factory

factory.ts

const urlFactory = {
  verify: (token: string) => `/verify/${token}`,
  deed: ({ orgId, deedId }: { deedId: number; orgId: number }) => `/deed/${orgId}/${deedId}`
}

// Turn a factory object (like the one above) into a mapped type.
type URLFactoryMapped<T extends Record<keyof T, (...args: any) => any>> =
  { [K in keyof T]: (...args: Parameters<T[K]>) => ReturnType<T[K]> }

const url = <T extends keyof typeof urlFactory>(key: T, ...args: Parameters<typeof urlFactory[T]>) => {
  // This is necessary for TS to understand that the function it gets through `key`
  // has the arguments of the function it gets through `key`.
  // https://stackoverflow.com/a/75514493/3844098
  const _urlFactory: URLFactoryMapped<typeof urlFactory> = urlFactory;
  return _urlFactory[key](...args);
}

console.log({
  verify: url('verify', 'my-token'),
  deed: url('deed', { deedId: 1, orgId: 2 }),
});