Статикодинамические валидаторы

tests.ts

type TestUserType = Assert<
	typeof User.Value,
	{
		readonly name: string
		readonly birthday: Moment
		readonly email: string & { Brand: "Email" } | undefined
	}
>

validators.ts

const Email = Brand({
	Email : Pipe( Str , Check( input => /@/.test( input ) ) )
})

const User = Rec({
	name : Str ,
	birthday : Pipe( Str , Moment ) ,
	email : Maybe( Email ) ,
})

function sayHello( user : typeof User.Value ) {
	console.log( 'Hello' , user.name )
}

function sendEmail( email : typeof Email.Value ) {
	console.log( 'Send to' , email )
}

const alice = User({
	name : 'Alice' ,
	birthday : '2000-01-01T12:00:00Z' ,
})

sayHello( alice )
if( alice.email ) sendEmail( alice.email )