Yup.string().matches() alternates beween valid and invalid as you are typing

Question

Trying to validate a phone number field in Formik using Yup validation schema, but when i use Yup.string().matches(/^[0-9]*$/g, 'This is not a number') it consistently alternates between valid and invalid on each change event.

    phone: Yup.string()
      .trim()     
      .matches(/^[0-9]*$/g, 'This is not a number')    
  }),

input field is of type tel. <Field type="tel" id="phone" name="phone" />

Answer 1

Ok, appears i could have been my RegEx after all that was causing this strange behavior.

• Original regEx: /^[0-9]*$/g
• Modified regEx: /^[\d]*$/g
• FINAL regEx: /^\d+$/ <-- This solved the problem.

My regEx knowledge is limited so i would be happy if somebody could tell me why the two first regEx codes caused the alternating state of validation.