Testing is a very important part when developing applications or providing maintenance. When we do not write tests, we need to verify each use case manually, and if we change anything on the code, we will need to perform all the testing manually again. The same happens when we need to maintain the code; developers usually test only what has been changed, but the correct thing to do would be regression tests to see whether the change did not break anything else. So spending some time writing tests can be a win at the end. You will spend a little bit more time writing code, but then you will be able to run all the tests with a single click and then verify what is broken and what is still working.

We are also very used to performing unit tests on the server-side code. Java, PHP, Ruby, C# communities offer a lot of options to perform unit tests on the server-side code, and sometimes, we can forget to test the frontend code (in this case Ext JS). But do not worry; there...