Inside a file like Button.tsx, I define the props like this:

type ButtonProps = {
  label: string;
  disabled?: boolean;
}

However, my editor (Visual Studio Code) is telling me that disabled is boolean. Not boolean | undefined, which is what I expect because of the optional ?.

If I specify disabled: string | boolean, then my editor is happy to acknowledge that disabled is a string or a boolean. If I change it to string | undefined, it goes right back to thinking it’s a string.

What am I doing wrong here?