Define custom message as function, not string

I need to integrate yup with i18n-next for translations. That’s why I need to be able to define messages as functions. There was discussion about this in #71, but I cannot make it work:

import { setLocale } from 'yup/lib/customLocale';

setLocale({
  string: {
    required: (obj) => {
      // obj is undefined
      return `${obj.path} is required`;  // this woudnt work as I don't have obj.path available
      // return 'required';  doesn't work either as this message is never displayed
    },
  },
});

Above is just an example, but it seems that functions are not allowed. But this is really weird, as function is used in the default locale - https://github.com/jquense/yup/blob/master/src/locale.js#L8 . So question is, are functions allowed and if yes, what I am doing wrong here?

[klis87]

@mshahov you shouldn’t put any t function in schema, based on your example, your email field should be email: Yup.string() .email('invalidEmail').required('required'), so notice, in schema you put i18n CODE, not translation. You need to you t function in React, so for instance {form.errors.email && t(form.errors.email)}

But generally error message are repetitive, thats why you might just have email schema like email: Yup.string() .email() .required(), with configured setLocale to provide defaults.

[fchubu]

@klis87 thanks a lot. @jquense Why that isn’t in the documentation yet?