Enhance ZodArray .min() and .length() Types

[samchungy]

Resolves #2658

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[colinhacks]

I dig the concept but this particular incarnation won't fly. That recursive alias can really hurt performance under the best of circumstances, and I'm sure there are many usages of z.number().length(10000) in the wild.

Since this ultimately resolves to a tuple type I'd be more amenable to keeping separate from ZodArray. (In retrospect even .nonempty() should probably have returned a ZodTuple).

Maybe a .tuple() method on ZodType?

z.string().tuple(3);
// ZodTuple<[ZodString, ZodString, ZodString]>

[samchungy]

Closing to rethink

[damian-balas]

@samchungy @colinhacks Any progress on this?

I need this type

type TypeINeed = [number, number];
type TypeItProduces = [number, ...number[]];

I've used this methonds, but none returned infered type as: [number,number]

{
  rooms: z.array(z.number()).nonempty().min(2).max(2).length(2),
  rooms: z.number().array().min(2).nonempty(),
  rooms: z.number().array().min(2).max(2).nonempty(),
}

Is there a way in the current version?

[samchungy]

@samchungy @colinhacks Any progress on this?

I need this type

type TypeINeed = [number, number];
type TypeItProduces = [number, ...number[]];

I've used this methonds, but none returned infered type as: [number,number]

{
  rooms: z.array(z.number()).nonempty().min(2).max(2).length(2),
  rooms: z.number().array().min(2).nonempty(),
  rooms: z.number().array().min(2).max(2).nonempty(),
}

Is there a way in the current version?

Sounds like you're after a tuple rather than an array

[dca123]

I've a usecase where I'm using length to ensure that I only have 8 elements in the array. Figured i should use tupples instead. However, I don't wanna wanna write those elements, 8 times in the array in my code (would be quite verbose) so i built this lil helper function to do that for me.

type TimesTuple<
  N extends number,
  T,
  R extends Array<T> = [],
> = R['length'] extends N ? R : TimesTuple<N, T, [...R, T]>;

function times<N extends number, T>(n: N, obj: T): TimesTuple<N, T> {
  const returnArr = [];
  for (let i = 0; i < n; i++) {
    returnArr.push(obj);
  }
  return returnArr as TimesTuple<N, T>;
}

would it make sense to have an optional param as the second parameter to have this repeating feature ? wonder how people commonly use the tuples feature 🤔