Conditionally validate using pipes

[ttonyh]

Now that the new version is released, what's the proper way to handle conditional validation? What's the best way to handle it based on parameters external to the schema (ie. not the typical scenario of "password" / "verify password")?

[fabian-hiller]

The official recommendation is to use the check action together with the forward method. This week or next I will also work on a partialCheck and refine action (issue #597) that will help cover more advanced cases.

import * as v from 'valibot';

const RegisterSchema = v.pipe(
  v.object({
    email: v.pipe(
      v.string(),
      v.nonEmpty('Please enter your email.'),
      v.email('The email address is badly formatted.')
    ),
    password1: v.pipe(
      v.string(),
      v.nonEmpty('Please enter your password.'),
      v.minLength(8, 'Your password must have 8 characters or more.')
    ),
    password2: v.string(),
  }),
  v.forward(
    v.check(
      (input) => input.password1 === input.password2,
      'The two passwords do not match.'
    ),
    ['password2']
  )
);

[fabian-hiller]

Update: Previously, check was not executed if the email field was untyped. This problem can now be solved with our new partialCheck action.

import * as v from 'valibot';

const RegisterSchema = v.pipe(
  v.object({
    email: v.pipe(
      v.string(),
      v.nonEmpty('Please enter your email.'),
      v.email('The email address is badly formatted.'),
    ),
    password1: v.pipe(
      v.string(),
      v.nonEmpty('Please enter your password.'),
      v.minLength(8, 'Your password must have 8 characters or more.'),
    ),
    password2: v.string(),
  }),
  v.forward(
    v.partialCheck(
      [['password1'], ['password2']],
      (input) => input.password1 === input.password2,
      'The two passwords do not match.',
    ),
    ['password2'],
  ),
);