matches() function not working correctly!?

[vnvyvu]

Describe the bug I use matches() and below regex string to check strong password myRegEx = (?=.*\d)(?=.*[a-z])(?=.*[A-Z])(?=.*[\W]).{8,}/gm

• send request: With password = "Password@123". Result: match myRegEx

• send request again: With password = "Password@123". Result: does not match myRegEx

Examples My code: https://stackblitz.com/edit/node-mub3gz or https://replit.com/join/mcrsnwazhi-vyvu

first request 2nd request

Additional context Validator.js version: 6.12.2 Node.js version: 16.10.0 OS platform: windows

Sorry if it's not a bug! ==> Temporarily I use isStrongPassword() instead of matches()

[tux-tn]

Strange behaviour, internally matches is only returning a new RegExp. Your issue may be related to the fact that your passing directly the modifiers in the regex, you are supposed to call matches this way:

str.matches(/(?=.*\d)(?=.*[a-z])(?=.*[A-Z])(?=.*[\W]).{8,}/, 'gm');

Since you are using express-validator you may find more help there or perhaps @fedeci have an idea about this issue.

[fedeci]

Hey @vnvyvu, does it work if you pass a string instead of a regexp?

body('pass').matches('(?=.*\d)(?=.*[a-z])(?=.*[A-Z])(?=.*[\W]).{8,}', 'gm')

[vnvyvu]

Hey @vnvyvu, does it work if you pass a string instead of a regexp?

body('pass').matches('(?=.*\d)(?=.*[a-z])(?=.*[A-Z])(?=.*[\W]).{8,}', 'gm')

yea, i tried and it worked!

[fedeci]

It has to be fixed for Regex objects however.

[fedeci]

Yeah, that happened to me too some times ago but never had a change to investigate it properly. I can't reproduce it in express-validator unit testing. It will be fixed as soon as I implement integration tests.

[tux-tn]

Is the problem related to express-validator? Can i close this issue?

[fedeci]

I'm not sure, but I assume it is.

[fedeci]

Found this comment: https://github.com/express-validator/express-validator/issues/1127#issuecomment-1026730522

Apparently pattern.test(str) is unreliable when preserving the same instance of a regex object, instead str.match(pattern) is. @tux-tn would a PR to change that method in this repo be accepted? We are already working on a fix on express-validator but an "upstream one" would be great!

[wyatt-substack]

Should either use .match or set pattern.lastIndex = 0; before calling .test.

[braaar]

Similar issue experienced downsteam in class-validator, as well https://github.com/typestack/class-validator/issues/1707