type ValidAttributes = "FOO" | "BAR" | "BAZ";

interface MyInterface {
  attributes: {
    [s in keyof ValidAttributes]: string;
  };
}

const doSomething = (data: MyInterface): void => {
  const foo = data.attributes.FOO;
  //Error:(10, 31) TS2339: Property 'FOO' does not exist on type '{ toString: string; charAt: string; charCodeAt: string; concat: string; indexOf: string; lastInde...'.

  const bar = data.attributes["BAR"];
  //Error:(13, 15) TS7017: Element implicitly has an 'any' type because type '{ toString: string; charAt: string; charCodeAt: string; concat: string; indexOf: string; lastInde...' has no index signature.
}