I'll create a custom hook for handling form validation in a React application. This hook will be versatile and reusable across different forms in your application. Let's implement it step by step.

This implementation provides a reusable custom hook for form validation in React applications. Here's a breakdown of what we've created:

1. validationRules.ts: This file contains reusable validation rules that can be applied to different form fields.

2. useFormValidation.ts: This is the custom hook that handles form state, validation, and submission. It provides:

   • State management for form values and errors
   • Field-level validation on change and blur events
   • Form-level validation on submission
   • Handling of form submission
3. SignupForm.tsx: This is an example component that demonstrates how to use the useFormValidation hook. It creates a simple signup form with username, email, and password fields, each with their own validation rules.

The custom hook is flexible and can be used with different forms by providing the initial values and validation rules specific to each form. It handles real-time validation as the user types or moves between fields, and it also performs a final validation before form submission.

To use this in your React application:

1. Copy the validationRules.ts and useFormValidation.ts files into your project.
2. Import the useFormValidation hook and any necessary validation rules in your form component.
3. Call the hook with your initial form values and validation rules.
4. Use the returned values and functions to build your form, similar to the SignupForm example.

This implementation provides a solid foundation for form validation in React applications. You can easily extend it by adding more validation rules or customizing the behavior to fit your specific needs.