type Command = (...args: Array<any>) => any;

type Client<C extends Command> = {
  command: C;
};

type ClientOptions<C extends Command> = {
  command: C;
}

type Setup<C extends Command> = (client: Client<C>) => unknown;

function test1<C extends Command>(
  setup: Setup<C>,
  options: ClientOptions<C>
): void {}

test1(async client => {
  // `client.command` type is `Command`, but should be inferred from `options.command`
  client.command('message');
  //     ^?
}, {
  command(message: string): void {
    console.log(message);
  }
});

function test2<C extends Command>(
  setup: Setup<C>,
  command: C
): void {}

test2(async client => {
  // works as expected, "client.command" type is inferred from `command` (the next argument)
  client.command('message');
  //     ^?
}, (message: string): void => {
  console.log(message);
});