TDD Training by JBrains

This is the second formal TDD training I have joined (The first one was conducted by Joey Chen(https://www.facebook.com/pg/91agile/about/?ref=page_internal). I could not find online line 😦  sad..). I would like to share some “Aha” moments along the way of this training.

Before that, allow me to share how i took the training(The first 2 series, which is free 🙂 ):

1. For 1st series, I implement without TDD first. The reason why I do that is I am just very curious of what is the time difference and other difference if i am lucky to find out.
2. For 2nd series, I just follow the video and stop where ever I need to think or research or take notes.

Ok. That’s enough. Let’s go to the my “Aha Wow” moments:

1. Really step by step by step : Fail -> Add Logic -> Pass -> Commit -> Refactor
2. It’s developers responsibility to cover more tests than the general requirements from clients. (I mention this because I have an assumption from my first TDD training that developers only need to add tests based on the requirements. )
3. Avoid more complex integration test by adding unit test when small class or methods come out along the way of implementation.
4. Triangulation concept somehow makes me feel better compare to one of TDD rules: You are not allowed to write any more production code than is sufficient to pass the one failing unit test. Because when ever I try to hardcode to make the test I feel so bad and keep wondering why not find the basic logic 1st.
5. Multilevel of abstraction code smell apply not only to same functionality, but also all same level functionality with different purpose.
   e.g.
   Assume inside one function, there is one logic related to getPrice, three logic related to display price. We should abstract both the getPrice logic and the displayPrice logic to achieve same level of abstraction for easy reading and maintaining.
6. Duplicated Concepts/Ideas: Do not repeat your self is not only about code, but also the way of covering the logic.
   e.g. if  A else if B else if C …. is one example of duplicated ideas
7. Intuitive and Mechanical approach of software designer (http://blog.jbrains.ca/permalink/becoming-an-accomplished-software-designer)
8. Refactoring based on single responsibility. Re-assign responsibility makes the code much more flexible and clear. For this I am not able to express it clearly by tying here. I strongly suggest you take the 2nd series of the training. Then you may feel it more.

“Post-Credit Scene”:
For my little test “For 1st series, I implement without TDD first.”, I did it within 15mins including the tests, while the training took more than one hour. But the test cases are much more less. Reason: I understand the logic of fraction adding. So my test only focus on the logic and with few special cases. I feel some tests inside the 1st series training are duplicated. So until now, I believe that TDD can help design the code but not necessarily helpful in every development scenario.