How to use TypeScript brand enum to type-check date string
🌱 seed (?)
[!tldr] Don't follow me, i'm lost too I don't know how to do this yet. I created this note to record the details of what I'd like to learn.
Objective: To have a type that accepts date strings like 2021-04-14, which we can use to create a valid Date instance.
Examples:
// should pass
new Date("2021-04-14") // "Wed Apr 14 2021 07:00:00 GMT+0700"
// should fail
new Date("14/04/2021") // ❌ Invalid Date
new Date("auouououoo") // ❌ Invalid DateOptionally, I want the ability to fine-tune the type, eg. to only accept YYYY-MM-DD or the ISO 8601 format.
TODO — prompts:
- how do we "connect" the type declaration to the function that checks/validates eg. the date string?
- what is Nominal typing exactly?
- what are Type guards exactly?
Link dump:
- https://gist.github.com/dphilipson/e62e894fabca8c614baffef9615d970b
- https://spin.atomicobject.com/2017/06/19/strongly-typed-date-string-typescript/
- https://basarat.gitbook.io/typescript/main-1/nominaltyping
- https://www.typescriptlang.org/play#example/nominal-typing
- https://levelup.gitconnected.com/nominal-typing-in-typescript-c712e7116006
In: TypeScript MOC