Slashdot Mirror
Why We Refactored JUnit
Bill Venners writes "In this article, three programmers tell the story of how their frustration with JUnit's API led to the creation of Artima SuiteRunner, a free, open source test toolkit and JUnit runner. These programmers simply wanted to create a small add-on tool to JUnit, but found JUnit's design non-intuitive and API documention poor. After spending time reading through JUnit's source code and attempting to guess at the API contracts, they gave up and rewrote it."
I'm surprised, it almost seems like you didn't read much of the information on the website... like you... maybe... just read the slashdot headline and then formed your opinion... because here's what they guy who re-wrote JUnit said:
"at one point I just threw up my hands and said to myself, "Why is this so hard? It would be easier to rewrite JUnit than figure it out."
Just some friendly advice: if you ever find yourself saying it would be easier to rewrite something rather than figure it out, slap yourself. Chances are you are wrong. I certainly was. Creating SuiteRunner was a huge amount of work. Despite my frustrations with JUnit, it would have been orders of magnitude easier to decipher JUnit's source code than to create a brand new testing toolkit."
Is intuitive design necessarily good in programming.?
Recursion is intuitive but not necessarily efficient in terms of performance.
At what point do we decide which is better intuitive design or efficient design.
XP is about writing code that can easily be successfully refactored. Total-design-up-front bigots think the code "sucks" because the design wasn't much more general than actually needed at the time, not realizing that making a design at the start of the project that meets the requirements as of the end of the project is almost always impossible, and all the effort in doing so is going to be wasted.
I believe that this quote is true for commercial software. The word processors, email clients and web browsers in the world should not be designed at the beginning of a project. The cost of doing that far outweighs the benifits. But...
When you are designing life critical applications (fly-by-wire, ABS, pacemaker, cancer radiation machine...etc) it is not acceptable to be redesigning while coding.
If you cannot model the way a system must react at all times, under any input, then what makes you think that your software should be responsible for someones life.
More and more software is being designed for life critical applications. If XP is being used to develop them, I'm worried. You cannot stumble onto 100% correct software. In a large system it takes a lot of money - an exponential curve, the last 3 bugs will likely take more money than the first 100 - time and a good design.
To help answer the grandparent's question: compile != matches API.
Can you write a test-compile program that checks whether the proper public/private/proctected access modifier keywords are set up right on each method? That the method was specified for 'short foo' but the implementor used 'int foo'? Or like Mithrandir said, that no additional methods have been added (such as an overloaded version)?
Basically, compile-compatability is not the same as using the precise APIs in the spec.
Ah, you do not understand the zen of XP yet. First you write the test. Then you write the code. Then you correct the code so the test passes. The sun is warm; the grass is green.