Comment by Nadya

Yes. Your type can encode what the proper format for a string should be and if a string is passed that does not meet that format it will throw an error allowing you to make any necessary adjustments to handle the new date year_quarter format.

eg. `type DateString = ${number}/${number}/${number}`

A super naïve check for using "/" instead of "-" as the separator character for a date formatted as a string. If a date is provided with some other separator character it will throw an error. If my function takes a DateString the string must be formatted correctly to pass the type check. Obviously this isn't enough (YYYY/MM/DD is different than DD/MM/YYYY) but the intention was to show a way to enforce something via types rather than validating a string to check that your have a DateString you can simply enforce that you have one.