Relying on hacks for production code is usually a red flag/code smell that indicates there was probably a better alternative. `string & {}` definitely feels like one of those hacks.

As an alternative, wouldn't it be better to map the list of supported values in a structure like an enum?

Example:

```

enum HelloWorldValue {

  Hello: 'hello',

  World: 'world'

}

const value = HelloWorldValue.Hello

```

And now you can call that enum when declaring a variable value and get its contents in autocomplete. As a nice bonus, because these are references and not strings, you can ask your IDE for all places instantiating those values, which can be a life saver.