Phantom type variant in TypeScript

text.ts

interface PlainText extends String {
  __plaintext__: never
}
interface Base64Encoded extends String {
  __base64Encoded__: never
}
interface Encrypted extends String {
  __encrypted__: never
}

export const text = (s: string): PlainText => <PlainText><any>s;

export const base64Encode = (s: PlainText): Base64Encoded => {
  return <Base64Encoded><any>atob(s.toString());
};

export const logBase64Encoded = (s: Base64Encoded): void => {
  console.log(s);
};

export const sendOverNetwork = (s: Encrypted): void => {
  // Dummy implementation
  return;
};

export const usage = () => {
  const plainText = text("Some text here");
  const base64Encoded = base64Encode(plainText);
  logBase64Encoded(base64Encoded);
  // logBase64Encoded(plainText);
};