Writing Tests

it is not easier to test the features manually.

say you have a contact form that the user enters some info in. its got a email and a message body field. you can test that just fine manually and it wont take you long at all. so you dont write any tests. you do it yourself and make sure your validations are working. it works great. cool. then next week you have to add a phone number field so you have to go back and test ALL the fields again to make sure you didnt break anything you did before. then a few days later you have to add another field, and you have to test everything manually again. Now multiple this by 5 since you have added 5 other forms on your site since that first contact form and it goes on an on.

tests make it easy to verify your code does what its supposed to (not just forms). It also saves you time and headaches. testing that form manually after each change would have wasted a lot of time when the test does it in 3 seconds. TDD also helps you formulate how you need to make things work. there are many advantages.

that being said, EVERYTHING probably doesnt deserve a test, and its up to you to decide if you want to or not. Also TDD follows a write tests first, write code later methodology, but it might not be necessary (or even possible) to write a test first before implementing the code. sometimes you just need to build some exploratory code to flesh things out.