> I've seen people create classes containing only a string That can be a good way to improve type-checking in code that would otherwise pass around bare string

> I've seen people create classes containing only a string That can be a good way to improve type-checking in code that would otherwise pass around bare strings. It reduces the chances that e.g. a plain text string is confused with an HTML string. If your language supports it, an opaque type alias would be more explicit: https://flow.org/en/docs/types/opaque-types/ https://flow.org/en/docs/types/opaque-types/