Nullable but if not null, meet the following requirements

[ahoiroman]

I want a field to be optional, but if someone enters something into the input, it must match some rules.

I got this schema:

const state = reactive({
  description: ''
})

const schema = v.lazy(() => v.object({
  description: v.nullable(
    v.pipe(
      v.string(),
      v.minLength(1, 'too short'),
      v.maxLength(255, 'too long')
    )
  )
}))

This does not work. If I dont enter anything to "description", I still get the "too short" message.
What did I miss?

[fabian-hiller]

By optional, do you mean an empty string? Here is one solution. Try it out in this playground.

import * as v from 'valibot';

const Schema = v.object({
  foo: v.union([
    v.literal(''),
    v.pipe(
      v.string(),
      v.minLength(3, 'too short'),
      v.maxLength(255, 'too long'),
    ),
  ]),
});