User object can have different types of social media accounts (email, google, twitter), and each type stores the username in a unique key (address for email, name for Google, and username for X (formerly known as Twitter)). I am attempting to dynamically retrieve the username for a given social type by passing the type as a parameter to a function.

interface email {
  address: string;
}
interface google {
  name: string;
}
interface twitter {
  username: string;
}

interface User {
  email?: email;
  google?: google;
  twitter?: twitter;
}
function getUsername(social: "email" | "google" | "twitter", user: User) {
  const userUsernames = {
    email: "address",
    google: "name",
    twitter: "username",
  } as const;
  const socialAccount = user[social];

  const username = socialAccount ? socialAccount[userUsernames[social]] : null;
  return username
}

But I am getting

Element implicitly has an ‘any’ type because expression of type ‘”address” | “name” | “username”‘ can’t be used to index type ’email | google | twitter’

I am aware that I could use if statements or a switch case to handle type-specific property access, but I am exploring if there’s a way to achieve this dynamically in TypeScript without explicitly checking each type. How can this be done while ensuring type safety?