Is it possible to type string literals using Valibot/v.pipe?

[zaydek]

I am wondering if it's possible to do something like:

import * as v from "valibot";

export const GlobalShopifyProductID = v.pipe(v.string(), v.startsWith("gid://shopify/Product/"));

type GlobalShopifyProductIDType = v.InferOutput<typeof GlobalShopifyProductID>;
//   ^ type GlobalShopifyProductIDType = string

But instead get something like gid://shopify/Product/${string} instead of string. Is that possible? I'm on version "valibot": "^0.31.0-rc.6".

[fabian-hiller]

Yes, this is possible but only when using custom or transform:

import * as v from 'valibot';

export const GlobalShopifyProductID = v.custom<`gid://shopify/Product/${string}`>(
  (input) => typeof input === 'string' && input.startsWith('gid://shopify/Product/')
);

type GlobalShopifyProductIDType = v.InferOutput<typeof GlobalShopifyProductID>;
//   ^ type GlobalShopifyProductIDType = `gid://shopify/Product/${string}`

import * as v from 'valibot';

export const GlobalShopifyProductID = v.pipe(
  v.string(),
  v.startsWith('gid://shopify/Product/'),
  v.transform((input) => input as `gid://shopify/Product/${string}`)
);

type GlobalShopifyProductIDType = v.InferOutput<typeof GlobalShopifyProductID>;
//   ^ type GlobalShopifyProductIDType = `gid://shopify/Product/${string}`

[zaydek]

Thank you, haven't seen this before. 🙂