Is conditional generation of pipes possible?

[ceigh]

I have some schema of the form in json (from backend), from which I generate the form markup itself and want to use this schema for validation via valibot.

// Part of form schema
const fieldOpts = {
  type: 'string',
  minLength: 4,
}

To do this, I conditionally add validators to the array and then pass them to pipe() (playground demo).

const rules: Parameters<typeof v.pipe>[1][] = []

if (fieldOpts.type === 'string')
  rules.push(v.string())

if (fieldOpts.minLength) 
  rules.push(v.minLength(fieldOpts.minLength))

const Schema = v.pipe(...rules)

It works, but I get type errors. So, how to fix the types and is it even possible to use pipe() in this way, maybe there is a better option?

Thank you in advance!

[fabian-hiller]

Yes, something like this is possible. Here is a playground.

import * as v from 'valibot';

// Part of form schema
const fieldOpts = {
  type: 'string',
  minLength: 4,
};

let Schema: v.GenericSchema | null = null;

if (fieldOpts.type === 'string') {
  const rules: v.PipeItem<string, string, v.BaseIssue<unknown>>[] = [];

  if (fieldOpts.minLength) rules.push(v.minLength(fieldOpts.minLength));

  Schema = v.pipe(v.string(), ...rules);
}

if (Schema) {
  const result = v.safeParse(Schema, 'example');

  console.log(result);
}

[fabian-hiller]

There will be a GenericPipeItem with the next release:

// Now
type T = v.PipeItem<string, string, v.BaseIssue<unknown>>;

// Then
type T = v.GenericPipeItem<string>;

[ceigh]

Thanks a lot, it works!
I didn't think about something like PipeItem...