Is Unit Testing worth the effort? [closed]

Question

I am working to integrate unit testing into the development process on the team I work on and there are some sceptics. What are some good ways to convince the sceptical developers on the team of the value of Unit Testing? In my specific case we would be adding Unit Tests as we add functionality or fixed bugs. Unfortunately our code base does not lend itself to easy testing.

Answer 1

[I have a point to make that I cant see above]

"Everyone unit tests, they don't necessarily realise it - FACT"

Think about it, you write a function to maybe parse a string and remove new line characters. As a newbie developer you either run a few cases through it from the command line by implementing it in Main() or you whack together a visual front end with a button, tie up your function to a couple of text boxes and a button and see what happens.

That is unit testing - basic and badly put together but you test the piece of code for a few cases.

You write something more complex. It throws errors when you throw a few cases through (unit testing) and you debug into the code and trace though. You look at values as you go through and decide if they are right or wrong. This is unit testing to some degree.

Unit testing here is really taking that behaviour, formalising it into a structured pattern and saving it so that you can easily re-run those tests. If you write a "proper" unit test case rather than manually testing, it takes the same amount of time, or maybe less as you get experienced, and you have it available to repeat again and again

Answer 2

I do not know. A lot of places do not do unit test, but the quality of the code is good. Microsoft does unit test, but Bill Gates gave a blue screen at his presentation.

Answer 3

For years, I've tried to convince people that they needed to write unit test for their code. Whether they wrote the tests first (as in TDD) or after they coded the functionality, I always tried to explain them all the benefits of having unit tests for code. Hardly anyone disagreed with me. You cannot disagree with something that is obvious, and any smart person will see the benefits of unit test and TDD.

The problem with unit testing is that it requires a behavioral change, and it is very hard to change people's behavior. With words, you will get a lot of people to agree with you, but you won't see many changes in the way they do things.

You have to convince people by doing. Your personal success will atract more people than all the arguments you may have. If they see you are not just talking about unit test or TDD, but you are doing what you preach, and you are successful, people will try to imitate you.

You should also take on a lead role because no one writes unit test right the first time, so you may need to coach them on how to do it, show them the way, and the tools available to them. Help them while they write their first tests, review the tests they write on their own, and show them the tricks, idioms and patterns you've learned through your own experiences. After a while, they will start seeing the benefits on their own, and they will change their behavior to incorporate unit tests or TDD into their toolbox.

Changes won't happen over night, but with a little of patience, you may achieve your goal.

Answer 4

Yes - Unit Testing is definitely worth the effort but you should know it's not a silver bullet. Unit Testing is work and you will have to work to keep the test updated and relevant as code changes but the value offered is worth the effort you have to put in. The ability to refactor with impunity is a huge benefit as you can always validate functionality by running your tests after any change code. The trick is to not get too hung up on exactly the unit-of-work you're testing or how you are scaffolding test requirements and when a unit-test is really a functional test, etc. People will argue about this stuff for hours on end and the reality is that any testing you do as your write code is better than not doing it. The other axiom is about quality and not quantity - I have seen code-bases with 1000's of test that are essentially meaningless as the rest don't really test anything useful or anything domain specific like business rules, etc of the particular domain. I've also seen codebases with 30% code coverage but the tests were relevant, meaningful and really awesome as they tested the core functionality of the code it was written for and expressed how the code should be used.

One of my favorite tricks when exploring new frameworks or codebases is to write unit-tests for 'it' to discover how things work. It's a great way to learn more about something new instead of reading a dry doc :)

Answer 5

Unit testing helps a lot in projects that are larger than any one developer can hold in their head. They allow you to run the unit test suite before checkin and discover if you broke something. This cuts down a lot on instances of having to sit and twiddle your thumbs while waiting for someone else to fix a bug they checked in, or going to the hassle of reverting their change so you can get some work done. It's also immensely valuable in refactoring, so you can be sure that the refactored code passes all the tests that the original code did.

Answer 6

I discovered TDD a couple of years ago, and have since written all my pet projects using it. I have estimated that it takes roughly the same time to TDD a project as it takes to cowboy it together, but I have such increased confidence in the end product that I can't help a feeling of accomplishment.

I also feel that it improves my design style (much more interface-oriented in case I need to mock things together) and, as the green post at the top writes, it helps with "coding constipation": when you don't know what to write next, or you have a daunting task in front of you, you can write small.

Finally, I find that by far the most useful application of TDD is in the debugging, if only because you've already developed an interrogatory framework with which you can prod the project into producing the bug in a repeatable fashion.