Unfortunately, this only worked because of a feature called import elision. When TypeScript outputs JavaScript files, it sees that Options is only used as a type, and it automatically drops its import. The resulting output looks kind of like this:

The onBlur function can take a SyntheticFocusEvent like it would if you had given it directly to an <input/> component, but you can also just call it: props.input.onBlur() to mark the field as blurred (inactive).