I guess I have posted a lot of technical stuff in my blog. However, I would like to go into a more theoritical side of things about software testing today – how to write a regression test.
So, what is regression test? Everyone knows that it is a set of test to make sure that existing functionality still works after new functionalities are added.
But how to write a good regression test? Most would think that the more tests you add into a regression test suite the better it is. This is a wrong view about regression test.
There are rules to follow in order to write an effective and efficient regression test suite. These rules are:


  • Test all the core functions of the system (not the little help screen)
  • Test the happy path and user would follow (not edge cases)
  • Partition it logically based on system or core modules so that it is easily readable and accessible
  • Partition a set of tests that will be run before every release (very important core modules) and others that will only be run when necessary (changes occur)
  • Keep it as simple and short as possible
  • Avoid repetitive steps
However, please bear in mind that I am not trying to say we do not want to test more in regression test. I simply mean that most edge cases and low level tests should be in the unit test level instead of functional regression test.