Interdependent attributes

[techpet]

I want to specify a new validation check where :

const Check = type({
  a: "0<integer<10",
  b: "a&integer<10",
})

so that the validation succeeds only if 0<a<b<10. Is there a way to achieve this?

[ssalbdivad]

Unfortunately, this is not currently possible via syntax alone. You'd have to use a narrowing function type for the object and compare the properties:

const check = type([
    {
        a: "0<integer<10",
        b: "0<integer<10"
    },
    "=>",
    ({ a, b }, problems) =>
        a < b || !problems.mustBe("an object with a less than b")
])

There is an issue #485 in the backlog to support these kinds of relative comparisons. The more feedback we get on it, the sooner we can prioritize it!

[techpet]

Thank you @ssalbdivad , I am completely fine with that solution. You are building a very well thought out library!