Component.ts

import * as Message from ‘../path/to/message.ts’;

const message: Message = Message.createText({ text: ‘hello world’ });

if (Message.isText(message)) {
  return <p>This is a text</p>;
} else {
  return <p>This is an image</p>;
}

// or

return fold({
  Text: () => <p>This is a text</p>,
  Image: () => <p>This is an image</p>,
})(message)