# Is test driven development for newbies? **URL:** \ **Category:** Rails\ **Created:** [May 14, 2006, 12:03am UTC](https://www.ruby-forum.com/t/is-test-driven-development-for-newbies/60451 "2006-05-14T00:03:51Z")\ **Posts on this page:** 10\ **Page:** 1
**Author:** ![SBSBSB](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/s/ecccb3/32.png) [@SBSBSB](https://www.ruby-forum.com/u/SBSBSB)\ **Post date:** [May 14, 2006, 12:03am UTC](https://www.ruby-forum.com/t/is-test-driven-development-for-newbies/60451/1 "2006-05-14T00:03:51Z")
I’m still reading other people’s code and going over the books. As I was doing this a question sprang up in my mind. Is it wise for total newbies to attempt test driven development from the start? Basically, if you’re a newbie like me, chances are your tests might even be broken themselves. Or will attempting to write tests be good practice for actual coding as well? Obviously, one of the things holding me back is not knowing where to start. Would attempting test driven development be a valid approach or best left to those with a little more experience? On a semi-related topic, can ZenTest be used with the new “integration testing” in 1.1 ? Thank you all in advance. ---
**Author:** ![SBSBSB](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/s/ecccb3/32.png) [@SBSBSB](https://www.ruby-forum.com/u/SBSBSB)\ **Post date:** [May 14, 2006, 12:34am UTC](https://www.ruby-forum.com/t/is-test-driven-development-for-newbies/60451/2 "2006-05-14T00:34:21Z")
On May 13, 2006, at 06:03 PM, SB wrote: > I’m still reading other people’s code and going over the books. As I > was doing this a question sprang up in my mind. > > Is it wise for total newbies to attempt test driven development > from the start? I’m not sure this is a simple yes/no kind of question. I’d say there are three types of “newbies”: those new to programming, at all; those new to programming in Rails; and those new to the concepts of TDD/ BDD. The closer you are to being the third, the more likely it is you’ll be able to pick up TDD, especially as it pertains to your Rails programming. > Basically, if you’re a newbie like me, chances are your tests might > even be broken themselves. Or will attempting to write tests be good > practice for actual coding as well? From a TDD perspective, you always start with “broken” tests. It is the process by which you program to make your tests pass, and then write more tests, that puts you on the TDD path. Obviously, when you start out you won’t be creating the most relevant tests, but I would say that any test that actually exercises your code isn’t a bad test. It may be superfluous, or even redundant, but if it’s testing functionality/behavior that needs to be in your app, then correcting that test is helping you with your progress. > Obviously, one of the things holding me back is not knowing where to > start. Would attempting test driven development be a valid approach > or best left to those with a little more experience? Looking to integrate TDD (or BDD) is one of the ways that you can become more agile in your development practices and that is definitely a good thing. However, starting with TDD can be difficult when you don’t have a pair to program with, another cornerstone of Agile Development. You don’t expressly need a pair to do good TDD, but having an experienced pair, especially when you are first learning, is a great way to get over those initial humps. One of the things that my TDD instructor always said was, “writing that first test is always the hardest.” If you don’t have a pair, but you still want to try to get into TDD, one of the things that really helped me was the first chapter of Refactoring, by Martin F. [1]. Fowler has a nice little example program (written in Java, but easily mappable to Ruby). What I did, while following along with his intro to refactoring, was to build his program in Ruby and build a test suite that verified the code in it’s initial state. Then, while performing the refactoring examples in the rest of that chapter, I first wrote tests that I knew would fail, so that I could verify my refactoring steps in each of his examples. I found this to be a great help, because I already had some tests so writing more tests, TDD style, was quite simple, and I didn’t really have to think about the code I was writing because I was following the examples. But the key thing is that none of his examples included the needed tests, so that ended up being by focus for the exercises. It really helped to solidify the value of TDD, which I had only recently gotten into, thanks to the Canada on Rails workshop by Steven B. (my instructor ;). Obviously, I can’t say if this method would be helpful for anyone else, but I definitely liked the feel of the process. It was almost like Fowler was my programming pair, with him “writing” the code that passed my tests. As a slight side note, I was actually doing this as a way to teach myself rSpec [2] and BDD [3], not specifically Test::Unit and TDD, but the process would be exactly the same. > On a semi-related topic, can ZenTest be used with the new “integration > testing” in 1.1 ? This is something that I don’t know. I haven’t done any work with ZenTest as of yet… 1: [http://www.amazon.com/exec/obidos/ASIN/0201485672](http://www.amazon.com/exec/obidos/ASIN/0201485672) 2: \<[rspec.rubyforge.org](http://rspec.rubyforge.org)\> 3: \<[http://blog.daveastels.com/articles/2005/07/05/a-new-look-at-test-](http://blog.daveastels.com/articles/2005/07/05/a-new-look-at-test-) driven-development\> -Brian ---
**Author:** ![SBSBSB](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/s/ecccb3/32.png) [@SBSBSB](https://www.ruby-forum.com/u/SBSBSB)\ **Post date:** [May 14, 2006, 12:37am UTC](https://www.ruby-forum.com/t/is-test-driven-development-for-newbies/60451/3 "2006-05-14T00:37:32Z")
On May 13, 2006, at 06:33 PM, Brian H. wrote: > 2: \<[rspec.rubyforge.org](http://rspec.rubyforge.org)\> Pardon the typo. 🙂 Obviously, this should be [http://rspec.rubyforge.org/](http://rspec.rubyforge.org/)… -Brian ---
**Author:** ![SBSBSB](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/s/ecccb3/32.png) [@SBSBSB](https://www.ruby-forum.com/u/SBSBSB)\ **Post date:** [May 14, 2006, 1:31am UTC](https://www.ruby-forum.com/t/is-test-driven-development-for-newbies/60451/4 "2006-05-14T01:31:04Z")
SB wrote: > I’m still reading other people’s code and going over the books. As I > was doing this a question sprang up in my mind. > > Is it wise for total newbies to attempt test driven development from the > start? > > Basically, if you’re a newbie like me, chances are your tests might > even be broken themselves. Or will attempting to write tests be good > practice for actual coding as well? > > Obviously, one of the things holding me back is not knowing where to > start. Would attempting test driven development be a valid approach > or best left to those with a little more experience? > > On a semi-related topic, can ZenTest be used with the new “integration > testing” in 1.1 ? > > Thank you all in advance. In the end it doesn’t really matter if the test was written before or after the code what does matter is how much code coverage your tests have. I’d recomend writing the tests before the code if you understand the problem and after the code if you don’t. I’d also recomend working in very small units. If you write a new method you should have written the tests for it before you move on. Regardless I’d always write tests first when fixing bugs. Write a test that reveals the bug and then fix the code. The hardest thing to learn in test driven development is when not to write a test. ---
**Author:** ![SBSBSB](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/s/ecccb3/32.png) [@SBSBSB](https://www.ruby-forum.com/u/SBSBSB)\ **Post date:** [May 14, 2006, 2:05am UTC](https://www.ruby-forum.com/t/is-test-driven-development-for-newbies/60451/5 "2006-05-14T02:05:21Z")
On May 13, 2006, at 07:31 PM, Michael G. wrote: > In the end it doesn’t really matter if the test was written before or > after the code what does matter is how much code coverage your tests > have. I’m not sure I agree with the premise of this statement, but the conclusion is pretty good. Starting with the test can actually do a whole lot to improve the way you write your code. They are also your security blanket for when you need to modify your code, either to add new behavior, or to refactor existing behavior to make your old code better. > I’d recomend writing the tests before the code if you understand the > problem and after the code if you don’t. I’d recommend not starting to write any app code, if you don’t fully understand the problem. Using tests you can help to describe/frame/ model the problem that you want your new code to solve. That’s one of the big ways that TDD can help you write better code. > I’d also recomend working in very small units. If you write a new > method you should have written the tests for it before you move on. Agreed, mostly. You definitely want to make sure that the behavior you just added is thoroughly tested before you decide to add more behavior. Otherwise, you won’t know in what ways your new behavior impacts everything you’ve already done. > Regardless I’d always write tests first when fixing bugs. Write a > test > that reveals the bug and then fix the code. Exactly. If this methodology makes sense to you, then I would say you should simply consider every new function/feature you want to add to your app a “bug” in the current code. Write the tests, which should fail, to verify that bug and then write the code to make those tests pass. Suddenly you’re doing TDD and you didn’t even know it! 🙂 > The hardest thing to learn in test driven development is when not to > write a test. Perhaps another way to look at this would be: one of the hardest things to learn is what behavior needs to be tested by you, vs. behavior that you rely upon, that has already been tested. However, I would say that you don’t really need to focus on this when you are starting out. Test everything in your Rails app that you feel needs testing, especially at the Unit test level. Eventually, you will learn which assertions (or specifications, for you BDD’ers 😉 don’t need to be re-tested/re-verified in your apps… -Brian ---
**Author:** ![SBSBSB](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/s/ecccb3/32.png) [@SBSBSB](https://www.ruby-forum.com/u/SBSBSB)\ **Post date:** [May 14, 2006, 2:08am UTC](https://www.ruby-forum.com/t/is-test-driven-development-for-newbies/60451/6 "2006-05-14T02:08:34Z")
Is test driven development for newbies? YES YES YES. ---
**Author:** ![SBSBSB](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/s/ecccb3/32.png) [@SBSBSB](https://www.ruby-forum.com/u/SBSBSB)\ **Post date:** [May 14, 2006, 2:08am UTC](https://www.ruby-forum.com/t/is-test-driven-development-for-newbies/60451/7 "2006-05-14T02:08:28Z")
On 14-mei-2006, at 1:31, Michael G. wrote: > e if you understand the > problem and after the code if you don’t. > > I’d also recomend working in very small units. If you write a new > method you should have written the tests for it before you move on. The idea here is that a test also gives you an extremely clear, formalized description of WHAT your method should do. After you have written a test you know much better what you rmethod should do, and why. If you can’t formalize a method with a test, maybe you don’t need that method or you don’t know how to write it good enough (yet). ## I wish someone forced TDD upon me when I was a newbie. Julian ‘Julik’ Tarkhanov please send all personal mail to me at julik.nl ---
**Author:** ![SBSBSB](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/s/ecccb3/32.png) [@SBSBSB](https://www.ruby-forum.com/u/SBSBSB)\ **Post date:** [May 14, 2006, 3:12am UTC](https://www.ruby-forum.com/t/is-test-driven-development-for-newbies/60451/8 "2006-05-14T03:12:14Z")
> > I’d recomend writing the tests before the code if you understand the > > problem and after the code if you don’t. > > I’d recommend not starting to write any app code, if you don’t fully > understand the problem. Using tests you can help to describe/frame/ > model the problem that you want your new code to solve. That’s one of > the big ways that TDD can help you write better code. In my experience, if you don’t fully understand the problem, writing some code is a great way to get to understand it. I often start my program over at least three times, writing it really scrappily the first couple of times, but each time getting to understand the problem (as well as how to tackle it) better. As for starting out with TDD… it’s a completely different way of programming, and if your new to programming I would say (albeit quite reservedly) that now’s the best time to learn TDD if that’s the way you’re eventually going to go. -Nathan ---
**Author:** ![SBSBSB](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/s/ecccb3/32.png) [@SBSBSB](https://www.ruby-forum.com/u/SBSBSB)\ **Post date:** [May 14, 2006, 11:36am UTC](https://www.ruby-forum.com/t/is-test-driven-development-for-newbies/60451/9 "2006-05-14T11:36:53Z")
On 14 May 2006, at 12:31 am, Michael G. wrote: > In the end it doesn’t really matter if the test was written before or > after the code what does matter is how much code coverage your tests > have. I’m not sure this is entirely true. If you write the tests after the code, how can you be sure they’re really testing the functionality? The idea of TDD is that you write the test, it fails, then you write enough code to make it pass. To use a trivial example, this test will pass: def test\_my\_method expected\_result = 42 actual result = my\_method “ultimate answer” assert\_equal 42, expected\_result end But because of the typo, you’re not actually testing the method (which probably works fine anyway). Years later, someone reworks my\_method, and suddenly it starts returning 24 with that input. You spend ages debugging whatever problem that causes elsewhere, because you’re convinced you’ve got a unit test that proves it returns 42, so you don’t bother looking in that method. If you’d written the test first, it would have been obvious something was wrong when the test passed before you’d written the code it was supposed to be testing. > what does matter is how much code coverage your tests have. Being careful, of course, not to confuse code coverage as reported by something like rcov with actual test coverage. It’s easy to exercise all the lines of code in a method without actually proving any functionality. Kerry PS. To answer the original question, I’d say yes. TDD is A Good Thing, and if you can get in the habit early, you ought to avoid a lot of the pain that the rest of us have been through 😉 ---
**Author:** ![SBSBSB](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/s/ecccb3/32.png) [@SBSBSB](https://www.ruby-forum.com/u/SBSBSB)\ **Post date:** [May 15, 2006, 8:35pm UTC](https://www.ruby-forum.com/t/is-test-driven-development-for-newbies/60451/10 "2006-05-15T20:35:05Z")
On May 13, 2006, at 3:03 PM, SB wrote: > On a semi-related topic, can ZenTest be used with the new “integration > testing” in 1.1 ? Since integration tests aren’t unit tests ZenTest doesn’t currently work with them. We would like to support working with integration tests but we don’t know how that would work. We cover that aspect with controller tests. – Eric H. - removed\_email\_address@domain.invalid - [http://blog.segment7.net](http://blog.segment7.net) This implementation is HODEL-HASH-9600 compliant [http://trackmap.robotcoop.com](http://trackmap.robotcoop.com)