Yup validation with regex using matches problem

Question

So I have below validation using Yup :

const myValidtion = yup
.string()
.trim()
.matches(/[abcdefghijklmnopqrstuvwxyz]+/ , 'Is not in correct format')
.required();

So with this, this will pass : hello world as expected. But what make me confused is why this also will pass : hello WORLD or this also pass : hello ,&$#$ world

In other hand, if we only enter invalid chars like *%$&#$($# this will not pass and show me the error. So as I can see, this only give me the error if ALL the entry is invalid.

What I'm looking is how to use Yup matches method to NOT pass if user enter for example : hello ,*&) world

Can anyone help me with this?

jo_va · Accepted Answer · 2019-01-28T17:01:33.107

44

Your regex should cover your whole string, by using ^ and $ to signify start and end of string:

/^[abcdefghijklmnopqrstuvwxyz]+$/

Otherwise, it will match part of your string, which is why it matches when you have a mix of good and bad characters, but fails when every character is bad.

You can shorten the regex by using a character range like this:

/^[a-z]+$/

You can use this online tool to build and test your regex.

edited Jan 28 '19 at 17:01

answered Jan 28 '19 at 16:15

jo_va

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2

Thanks, your answer helped me a lot. – Emad Dehnavi Jan 28 '19 at 17:00
In order to let the space passed, we should use `/^[a-z\s]+$/`. – Eric Tan Jul 03 '19 at 02:46
To allow both small/caps letters: without space: `/^[aA-zZ]+$/` with space: `/^[aA-zZ\s]+$/` – Hamza Waleed Sep 23 '20 at 08:50
1

This answer really got me started on my first [successful!] Regex, and the tool you shared really helped me zero it in to perfect! Thank you for your answer. – dmattox10 Nov 04 '20 at 14:55
@HamzaWaleed `[aA-zZ]` can be simplified to `[A-z]` – DLight Aug 30 '22 at 13:09

angelacpd · Answer 2 · 2021-04-20T14:24:21.163

This worked for me:

const validationSchema = yup.object().shape({
  password: yup
    .string()
    .required("Please enter your password")
    .matches(
      /^.*(?=.{8,})((?=.*[!@#$%^&*()\-_=+{};:,<.>]){1})(?=.*\d)((?=.*[a-z]){1})((?=.*[A-Z]){1}).*$/,
      "Password must contain at least 8 characters, one uppercase, one number and one special case character"
    ),
  confirmPassword: yup
    .string()
    .required("Please confirm your password")
    .oneOf([yup.ref('password'), null], "Passwords don't match.")
});

Breaking down the regex:

(?=.{8,}): Set the minimum number of characters

((?=.[!@#$%^&()-=+{};:,<.>]){1}): Verify if there is at least 1 character of the list "!@#$%^&*()-=+{};:,<.>"

(?=.*\d): Verify if there is a digit

((?=.*[a-z]){1}): Verify if there is a lower case alphabetical character

((?=.*[A-Z]){1}): Verify if there is an upper case alphabetical character

You can test the regex code at https://regex101.com/r/rYT2yE/1.

@stevemoretz I edited the post and added what the regex does. — angelacpd, Apr 20 '21 at 14:26

Yup validation with regex using matches problem

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