👀 Views: 0 💬 Answers: 1 📅 Created: 2025-09-27

regex validation javascript react node.js

I'm writing unit tests and I'm migrating some code and I'm having a hard time understanding I've looked through the documentation and I'm still confused about I've been struggling with this for a few days now and could really use some help. After trying multiple solutions online, I still can't figure this out. While refactoring our web application built with React and Node.js, I need to ensure that the user input validations are both comprehensive and flexible. We're working with various inputs such as usernames, passwords, and emails, each requiring different regex patterns. For usernames, the requirement is to allow alphanumeric characters, underscores, and dashes, with a length between 3 to 15 characters. I initially tried this regex: ```javascript const usernameRegex = /^[a-zA-Z0-9_-]{3,15}$/; ``` However, this doesn't account for edge cases like leading or trailing spaces, which can lead to confusion for users. To overcome this, I modified it to: ```javascript const usernameRegex = /^(?!\s)([a-zA-Z0-9_-]{3,15})(?<!\s)$/; ``` Next, for password validation, I need to ensure it includes at least one uppercase letter, one lowercase letter, one digit, and one special character, with a minimum length of 8 characters. My initial attempt was: ```javascript const passwordRegex = /^(?=.*[a-z])(?=.*[A-Z])(?=.*\d)(?=.*[!@#$%^&*])[A-Za-z\d!@#$%^&*]{8,}$/; ``` This worked well, but I found it was too restrictive for users who might prefer simpler passwords. Adjusting it to make the special character optional resulted in: ```javascript const passwordRegex = /^(?=.*[a-z])(?=.*[A-Z])(?=.*\d)[A-Za-z\d!@#$%^&*]{8,}$/; ``` Lastly, for email validation, I started with a standard regex: ```javascript const emailRegex = /^[a-zA-Z0-9._%+-]+@[a-zA-Z0-9.-]+\.[a-zA-Z]{2,}$/; ``` This seemed adequate, but I realized it didn't cater to all possible TLDs, especially newer ones like '.xyz'. After some consideration, I found a more inclusive regex: ```javascript const emailRegex = /^[a-zA-Z0-9._%+-]+@[a-zA-Z0-9.-]+\.[a-zA-Z]{2,10}$/; ``` As we move forward, I’m looking for best practices around regex performance and maintainability, especially since user input validation is critical for both security and user experience. Suggestions on how to better structure these regex patterns or any potential pitfalls to watch out for would be highly appreciated. Also, if anyone has experience with integrating such validations seamlessly into a form library like Formik, that would be invaluable. I'm using Javascript 3.10 in this project. Has anyone dealt with something similar? I'm on CentOS using the latest version of Javascript. For context: I'm using Javascript on CentOS. Thanks for your help in advance! This is my first time working with Javascript 3.11. Hoping someone can shed some light on this.