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Excuse me for interrupting the budding flame war, but I have a question regarding the subject, which you seem qualified to answer? :-) My experience is the sam

by berntb 15y ago

Excuse me for interrupting the budding flame war, but I have a question regarding the subject, which you seem qualified to answer? :-) My experience is the same as (what I believe is) the usual criticism of tests-first. I often need to rethink the API to my functions/methods, sometimes more than once. This goes for both external and internal APIs, so it doesn't help with detailed interface specifications between modules. Test-first is a problem, since it needs a fixed interface before I'm ready to lock down the interface. I tend to instead write inside-out; a few pages of code and then write tests for that code. That model isn't really kosher/halal/etc, according to TDD?

tychof 15y ago
One benefit to TDD is that you become a user for your API much more quickly, and so your API doesn't need to change as much. TDD suggests 3 steps: 1. Write one test 2. Write the minimal code to make it pass 3. Refactor the code you've got. Try not to think of tests as immutable. You can throw away tests when they don't provide value. Finally, make sure you're using an IDE with refactoring support. That helps immensely when you make an API change which will affect your tests.
- berntb 15y ago
  OK, thanks to you and zumda. Interesting TDD argument. I'll buy a book or something and try again when my present hobby project is done and I have time for experimenting. (IDE refactoring needs a stricter language than I prefer. Also, without an IDE and using my old eyes I have 2 A4 of code + 1 A4 of bash on a 24" monitor...)
  - zts 15y ago
    If you're looking for book suggestions, I'd recommend "Growing Object-Oriented Software, Guided By Tests" by Steve Freeman and Nat Pryce. It's pretty pragmatic, and the treatment of the subject is pretty thought-provoking (at least, I thought so when I read it). The examples are all Java, but the accompanying website (http://www.growing-object-oriented-software.com/ http://www.growing-object-oriented-software.com/) has links to reimplementations in several other languages.
zumda 15y ago
According to TDD writing inside-out is one of the points it tries to combat. The point of using TDD to write interfaces is that you first write the code you wish you had, and then implement it. The other way around you could end up with code that is optimized for the code inside the module, and not optimized for using it. Of course now you have to rewrite your tests and your code when changing an API, but at least you know that no other part of your application got broken by the new API. I personally like the TDD approach to write interfaces, since then I won't take shortcuts just because it is easier to do in the specific module that I'm programming/extending. It will actually produce code that can be used easily from the outside and removes a lot of dependencies in the process.

by berntb 15y ago

tychof 15y ago

One benefit to TDD is that you become a user for your API much more quickly, and so your API doesn't need to change as much. TDD suggests 3 steps: 1. Write one test 2. Write the minimal code to make it pass 3. Refactor the code you've got. Try not to think of tests as immutable. You can throw away tests when they don't provide value. Finally, make sure you're using an IDE with refactoring support. That helps immensely when you make an API change which will affect your tests.

berntb 15y ago
OK, thanks to you and zumda. Interesting TDD argument. I'll buy a book or something and try again when my present hobby project is done and I have time for experimenting. (IDE refactoring needs a stricter language than I prefer. Also, without an IDE and using my old eyes I have 2 A4 of code + 1 A4 of bash on a 24" monitor...)
- zts 15y ago
  If you're looking for book suggestions, I'd recommend "Growing Object-Oriented Software, Guided By Tests" by Steve Freeman and Nat Pryce. It's pretty pragmatic, and the treatment of the subject is pretty thought-provoking (at least, I thought so when I read it). The examples are all Java, but the accompanying website (http://www.growing-object-oriented-software.com/ http://www.growing-object-oriented-software.com/) has links to reimplementations in several other languages.

zumda 15y ago

According to TDD writing inside-out is one of the points it tries to combat. The point of using TDD to write interfaces is that you first write the code you wish you had, and then implement it. The other way around you could end up with code that is optimized for the code inside the module, and not optimized for using it. Of course now you have to rewrite your tests and your code when changing an API, but at least you know that no other part of your application got broken by the new API. I personally like the TDD approach to write interfaces, since then I won't take shortcuts just because it is easier to do in the specific module that I'm programming/extending. It will actually produce code that can be used easily from the outside and removes a lot of dependencies in the process.