Formik + Yup don't validate input if untouched

问题

I am trying to use Formik + Yup to validate my form, but currently if I touch one field, and then try and submit, a field that has a minimum length will validate, and not allow me to submit.

Following my code sandbox (https://codesandbox.io/s/focused-bardeen-5fiuz), I want the user to be able to submit the form if they just change the firstName field, but without entering anything for the country field. I tried both the .notRequired() and .nullable(true) params, but did not work. Any idea how to achieve this?

回答1:

You can try use custom validate with test. A working example here https://codesandbox.io/s/laughing-dust-f9wet

country: yup
      .string()
      .test("isValidCode", "Country must be 2-letters (ISO codes).", value => {
        if (!value) {
          return true;
        }
        return value.toString().length === 2;
      })

来源：https://stackoverflow.com/questions/56844264/formik-yup-dont-validate-input-if-untouched