React hook form with zod resolver optional field

Question

I want to make a form with React-hook-form and zod resolver where all fields are optional but fields still required despite making them optional in zod schema:

const schema = z.object({
    name: z.string().min(3).max(50).optional(),
    description: z.string().min(3).max(255).optional(),
    image: clientImageSchema.optional(),
  })
const {...} = useForm({ resolver: zodResolver(schema) }) 

when submitting the form with blank inputs it validates fields as required. Where is the error or the mistake?

Answer 1

I had the same issue. There may be some bug or issue regarding the handling of empty strings. There was similar thing happening with enums https://github.com/react-hook-form/react-hook-form/issues/3985 .

For now just running the field with .preprocess() seems to be working. What I mean is:

const schema = z.object({
  // Watch out, z.preprocess takes two arguments
  foo: z.preprocess(
    (foo) => {
      // this line won't work
      // return foo

      // this line will work, dunno why
      // console.log(typeof email)

      // I'm using this
      if (!foo || typeof foo !== 'string') return undefined
      return foo === '' ? undefined : foo
    },
    z
      .string()
      .email({
        message: 'Please correct your email address',
      })
      .optional(),
  ),
})

So this will give us an optional field that will be validated as an email field once not-empty. There may be some other way but that's what I've found.