How can I implement unit testing for custom validation in my application?

How can I implement unit testing for custom validation in my application?

You can start by using a testing framework like Jest or Mocha. First, create your custom validation function.

What should I include in my test cases for the validation function?

Include cases for valid inputs, invalid inputs, and edge cases. Ensure to test all possible scenarios.

Can you give me an example of a test case?

Sure! For a validation function that checks if a string is an email, you could test valid emails like '[email protected]' and invalid ones like '[email protected]'.

How do I run these tests once I've written them?

You can run your tests using the command line. For Jest, use npm test, and for Mocha, use mocha.