Tests

Hi, I’m a fairly new web dev who had just finished my bachelors in CS and work part time as an IT consultant. Throughout my education I feel like I’ve learnt about many important techniques and concept, but even though my professors and other professionals say that tests are very important it has never been a focus.

Because of that I always downprioritize writing automated tests, and it always leads to manually testing the application. I’ve tried to write tests, but writing them is hard since I don’t know what constitutes a good test. Additionally my testing methods hasn’t been flexible, and it ends up feeling tedious and painful to work with.

Firstly, what constitutes a good test? Secondly, what utilities can I create/use to make coding tests less tedious?

Also, I’m wondering why use unit tests, doesn’t integration tests basically ensure that both the unit and the components work correctly?