How to validate Date object through io-ts (typescript)?

Question

I haven't been able to find documentation on this, so here I am StackOverflow.

I have an interface that I want to convert and use in io-ts' run-time validation. This interface includes a field with type Date on it. I've looked through the rest of the commands on t when importing io-ts as t and I can't find a way to validate that it's a date

Ex:

export interface Transaction {
  transactionDate: Date,
  phrase: string
}

How do I convert this into a type using io-ts? Ideally it would be something like this

export const Transaction = t.type({
  transactionDate: t.date,
  phrase: t.string
})

The only thing that I've found that works is setting the Date as type t.string, but that would let any kind of string through.

Answer 1

I found an npm package called io-ts-types. I was looking at the documentation thinking it was part of io-ts already.

https://github.com/gcanti/io-ts-types

There's a module built into io-ts-types dedicated to dates

https://gcanti.github.io/io-ts-types/modules/date.ts.html

Example of usage

import * as td from 'io-ts-types'

const dateObj = t.type({
  date: td.date
})

const test = {
  date: new Date()
}

You can use the decoder to validate that this works like so isLeft(dateObj.decode(test))